EPAC 2006 - List of Keywords

A B C D E F G H I K L M O P Q R S T U V W X

electron

Paper	Title	Other Keywords	Page
MOXPA01	The Global Design Initiative for an International Linear Collider	collider, positron, linear-collider, proton	1
	B.C. Barish CALTECH, Pasadena, California
	Two years after the selection of the SC technology and a few months before the release of the ILC Conceptual Design Report, the presentation will review the main issues towards an ILC project and the world-wide collaboration presently set-up to address them. It will especially emphasize the challenges both technical (performances, reliability, machine protection, cost minimisation, industrialisation) and organisational, in a world-wide collaboration for the first time from the very beginning of the project. It will then present the status of the performances already demonstrated, the R&D presently envisaged to improve them or reduce the cost, the test facilities set-up to address them and the effort towards technology transfer to industry and industrialisation. Finally, it will present the plans and schedule for the future as well as the site specific parameters and cost issues.
	Transparencies

MOYAPA01	Laser-plasma Wakefield Acceleration: Concepts, Tests and Premises	laser, plasma, acceleration, target	10
	V. Malka Ecole Polytechnique, Palaiseau J. Faure CEA, Gif-sur-Yvette Y. Glinec, A. Lifschitz LOA, Palaiseau
	The presentation will review all novel methods presently developed to reach high accelerating fields from the concepts, to simulations, feasibility demonstration in real tests and performances presently achieved. It will point out and compare their potential but also their technical challenges and possible limitations. It will also present the necessary R&D and the tests presently envisaged including schedule and milestones not only in terms of fields but also of beam quality preservation and power efficiency. Finally, possible future applications will be suggested.
	Transparencies

MOYBPA02	Operation of High-luminosity Meson Factories and the Challenge to go to the Next Generation	luminosity, factory, KEKB, feedback	19
	K. Akai KEK, Ibaraki
	This talk will present an overview of the operational status of B- and Phi-Factories, and address their present luminosity performance and limitations, such as electron cloud effects. It will also discuss upgrade plans, including motivation and beam dynamics challenges, new ideas, R&D and machine experiments in view of the next generation of meson factories with ~100 times more luminosity. In particular, it will address machine tests with strong RF focusing, crab cavity developments and first operational experience at KEKB.
	Transparencies

MOZBPA01	Results from the VUV-FEL	radiation, FEL, undulator, laser	34
	J. Rossbach DESY, Hamburg
	The talk will provide the latest results from the VUV-FEL. It will cover the general performance of the machine and comparison to theory. A status will be given of the performance of key systems: the gun, accelerating modules and RF systems, electron and photon beam diagnostics, timing and synchronization and undulator performance. Future developments and implementations will also be discussed (and implications to the XFEL).
	Transparencies

MOPCH003	Seeding SPARC Facility with Harmonic Generation in Gases: Preliminary Tests of the Harmonic Generation in Gas Chamber	laser, undulator, FEL, radiation	47
	O. Tcherbakoff, M. Bougeard, P. Breger, B. Carré, D. Garzella, M. Labat, G. Lambert, H. Merdji, P. Monchicourt, P. Salieres CEA, Gif-sur-Yvette M.-E. Couprie SOLEIL, Gif-sur-Yvette A. Doria, L. Giannessi ENEA C.R. Frascati, Frascati (Roma)
	In High Gain Harmonic Generation Free Electron Laser configuration, an external light source is injected in the first part of an undulator. The electron-photon interaction leads to a coherent light emission in the second part of the undulator. We propose to use the High Order Harmonic Generation in gases process as the seed for SPARC project (Frascati, Italy). With this facility, the electron beam is accelerated to 200 MeV and passes through an undulator of 6 sections. The preliminary tests on the seeding chambers presented in this paper have been realised at the CEA (Saclay, France). The experiment is based on three vacuum chambers. In the first one, a Ti: Sa laser (800 nm, 2.5 mJ, 50 fs, 10 Hz) is focussed in a 10 Hz pulsed gas jet (Argon or Xenon), producing harmonics of the fundamental. Filters in the second chamber enable the selection of the harmonic (3rd or 5th). Finally, a telescope focuses the harmonic beam at a given position. The whole module is to be moved to the SPARC facility. Appropriate tuning of the undulator gaps will amplify the 3rd and 5th harmonics seeded, as well as non-linear harmonics of those wavelengths, allowing the perspective of producing a FEL at 53 nm

MOPCH004	Coherent Harmonic Generation Experiment on UVSOR-II Storage Ring	laser, storage-ring, undulator, klystron	50
	M. Labat CEA, Gif-sur-Yvette M.-E. Couprie SOLEIL, Gif-sur-Yvette T. Hara RIKEN Spring-8 Harima, Hyogo M. Hosaka, M. Katoh, A. Mochihashi, M. Shimada, J. Yamazaki UVSOR, Okazaki G. Lambert RIKEN Spring-8, Hyogo D. Nutarelli LAC, Orsay Y. Takashima Nagoya University, Nagoya
	Harmonic Generation schemes on Free Electron Laser devices are very promising. The injection of a traditional laser source inside the first undulator leads to an efficient energy modulation of the electron bunch, and therefore, its spatial modulation, resulting in a more coherent light emission along the second undulator. Experiments have been performed on the UVSOR-II Storage Ring at Okazaki (Japan) with electrons stored at an energy of 600 MeV, and using a 2.5 mJ Ti:Sa laser at 800 nm wavelength, 1 kHz repetition rate, and 100 fs up to 2 ps pulse duration. The experimental setup is presented, including the transport alignment and synchronisation between the laser and the electron beam. The third harmonic at 266 nm has been characterised versus various parameters: current, RF cavity voltage, undulator gap, magnetic functions of the storage ring, and laser pulse duration. Those results are compared with theory via analytical models and simulations.

MOPCH006	Beam Adaptation at the Infrared FEL, CLIO	undulator, FEL, simulation, quadrupole	56
	J.P. Berthet, F. Glotin, J.-M. Ortega CLIO/ELYSE/LCP, Orsay W. Salah The Hashemite University, Zarka
	The infrared free-electron laser CLIO is tunable from 3 to 150 5m by operating its driver RF linear accelerator between 50 and 12 MeV. This is the largest spectral range ever obtained with a single optical cavity. We have studied the electron beam transverse adaptation in the FEL undulator throughout the spectral and energy range. Each beam dimension is measured by a moving wire whose temperature dependant resistivity is monitored. The results are compared with simulations computed with the TRANSPORT code.

MOPCH007	Undulators for a Seeded HGHG-FEL Test Bench at MAX-lab	undulator, FEL, radiation, laser	59
	J. Bahrdt, H.-J. Baecker, W.F. Frentrup, A. Gaupp, K. Goldammer, A. Meseck, M. Scheer BESSY GmbH, Berlin S. Werin MAX-lab, Lund
	Undulators for a Seeded HGHG-FEL at MAX-lab Within the European FEL Design Study a seeded HGHG-FEL will be set up at MAX-lab. In the modulator, a planar pure permanent magnet undulator, the 3rd harmonic of a Ti:Sapphire laser (267nm) interacts with the electron beam. In the following dispersive section the energy modulation is converted into a spatial modulation. The radiator emits at the third harmonic (89nm). The radiator has an APPLE II type magnetic structure providing full polarization control. The undulators and the dispersive section are currently built at BESSY. The electron beam height at MAX-lab of 400mm requires a specific design of the undulator carriages. The magnetic and mechanical design of the HGHG stage will be presented.

MOPCH008	Considerations for Double Pulse Lasing from the BESSY-FEL	FEL, simulation, bunching, laser	62
	K. Goldammer, B.C. Kuske, A. Meseck BESSY GmbH, Berlin
	BESSY proposes a linac-based High-Gain Harmonic-Generation (HGHG) free electron laser (FEL) facility with three independent FEL lines. Two to four HGHG stages downconvert the initial seed wavelength (230nm to 460nm) to the desired radiation range (1.24nm to 51nm). High FEL gain is ensured as the seed radiation interacts only with unperturbed parts of the electron bunch in every HGHG-stage. This so-called fresh-bunch-technique relies on dipole chicanes that delay the electron bunches relative to the radiation. Fresh-bunch chicanes are incorporated prior to each modulator in the BESSY-FEL allowing the bunch to completely travel through all undulators. However, simulations show that bunch parts that have previously lased generate a noticeable radiation power level in the final amplifiers. This motivated simulation studies on the significance and applicability of such inherent additional pulses. It is revealed that the BESSY-FEL provides the opportunity to deliver double pulses at the FEL exit being of high interest to the user community. Temporal seperation and intensity levels can be controlled by carefully optimising the properties of the magnetic chicanes.

MOPCH011	Jitter Measurement by Spatial Electro-optical Sampling at the Flash Free Electron Laser	laser, FEL, diagnostics, polarization	71
	A. Azima, S. Düsterer, J. Feldhaus, H. Schlarb DESY, Hamburg A.L. Cavalieri MPQ, Garching, Munich D. Fritz Michigan University, Ann Arbor, Michigan K. Sengstock Uni HH, Hamburg
	For pump-probe experiments carried out at the VUV-FEL at DESY, FEL laser pulses with 32 nm wavelength have to be synchronized with high precision to optical laser pulses generated by a TiSa oscillator. To measure the relative timing variations between the FEL and the optical laser, an electro-optical experiment to determine the electron beam arrival time at the undulator has been installed. Here, the electron beam profile is encoded spatially into the laser pulse and readout by an intensified camera. A similar experimental setup has been successfully used at the sub-picosecond pulsed source (SPPS) at higher charge and shorter rms bunch length. In this paper, we report about the achievements and difficulties of the Timing Electro-Optical (TEO) setup, that allows to post-order experimental user data with a precision of 100 fs rms and better.

MOPCH012	FEL Disturbance by Ambient Magnetic Field Changes	PETRA, DESY, proton, linac	74
	H. Kapitza, P. Göttlicher, N. Heidbrook, H. Schlarb DESY, Hamburg
	The VUV-FEL at DESY in Hamburg (Germany) is mostly located inside the circular accelerator PETRA which serves as an injector for the electron proton collider HERA. SASE was regularly lost in the VUV-FEL when protons were ramped to the injection energy in PETRA. This effect was mediated by magnetic field changes in the order of 1 microtesla, caused by time-dependent uncompensated magnet currents of more than 800 A which made PETRA act like a large current loop. The resulting beam displacements of several hundred micrometers in the undulators proved to be enough to make SASE fail. This serious disturbance of user runs was eliminated by introducing an improved compensation scheme which further limits residual currents in PETRA during proton injection. The consequences of this observation for the design of the XFEL are briefly discussed.

MOPCH016	Bunch Compression Monitor	radiation, FEL, SASE, acceleration	86
	H. Delsim-Hashemi, J. Rossbach, P. Schmüser Uni HH, Hamburg O. Grimm, H. Schlarb, B. Schmidt DESY, Hamburg A.F.G. van der Meer FOM Rijnhuizen, Nieuwegein
	An accelerated bunch of electrons radiates coherently at wavelengths longer than or comparable to the bunch length. The first generation Bunch Compression Monitor (BCM) that is installed at the VUV-FEL applies this principle by measuring the total radiation intensity. For a better control on the degree of the compression, the radiated intensity in different bandwidth can be used. Dependent on the changes in the structure of the bunch, its radiation spectrum changes correspondingly. A new generation BCM uses wavelength dependent diffracting devices and multi-channel sensors to measure the signal in different wavelength channels simultaneously. This paper describes the construction of the first prototypes and experimental results in different short wavelength bands measured at the linac of the VUV-FEL at DESY, Hamburg.

MOPCH018	Macro-Pulse Generation in a Storage-Ring Free-Electron Laser: A Single-Particle Plus FEL Numerical Approach	FEL, simulation, storage-ring, ELETTRA	89
	F. Curbis, E. Allaria, G. De Ninno ELETTRA, Basovizza, Trieste
	In a storage-ring free-electron laser (FEL), the onset and growth of intra-cavity power at the fundamental resonant wavelength is naturally accompanied by coherent emission at higher harmonics. Contrary to what happens in single-pass linac-based devices, the electron beam is re-circulated in the storage ring and the microbunching becomes thermalized. As a consequence, a correct theoretical understanding of the process requires a proper modelling of the turn-by-turn evolution of the electron-beam phase space, both inside the undulators (where the FEL interaction takes place) and along the ring. To simulate this process we have coupled an ad hoc modified version of the 3D numerical code Ginger (which models the FEL interaction) together with a linear one-turn map (which propagates the electron beam along the ring). We present our results and draw a comparison with previous simplified approaches. We also present the first benchmarking of experiments carried out with the ELETTRA storage-ring FEL.

MOPCH025	Laser Comb: Simulations of Pre-modulated E- Beams at the Photocathode of a High Brightness RF Photoinjector	laser, gun, cathode, simulation	98
	M. Boscolo, M. Ferrario, C. Vaccarezza INFN/LNF, Frascati (Roma) I. Boscolo, F. Castelli, S. Cialdi INFN-Milano, Milano P. Musumeci INFN-Roma, Roma
	A density modulated beam at the photocathode though the proper modulation of the laser beam pulse does not change substantially emittance and energy spread, properties directly related to FEL. It has been found that bunch density modulation is transformed into energy modulation along the propagation through the injector. There are some physical arguments that suggest a possibility to use this modulation for the enhancement of the FEL process, or for the production of plasma wakes. Preliminary beam dynamics studies have been carried on to explore the use of electron beam pre-modulation at the cathode to adjust their longitudinal structure at the end of the beamline. Energy modulation at the end of the beamline could eventually be turned into current modulation through a magnetic compressor with R56<0. The feasibility of this experiment has to be investigated carefully, preliminary studies are discussed here. This paper focuses on simulations that explore the properties of the energy modulation at the end of the beamline correlated to the initial characteristics of the train of electron pulses. M. Biagini et al. “Beam Dynamics Studies for the SPARC Project”, Proc. of PAC03.

MOPCH029	Status of the SPARC Project	laser, emittance, gun, undulator	110
	P. Musumeci, D. Levi, M. Mattioli, G. Medici, D. Pelliccia, M. Petrarca Università di Roma I La Sapienza, Roma D. Alesini, M. Bellaveglia, S. Bertolucci, R. Boni, M. Boscolo, M. Castellano, A. Clozza, L. Cultrera, G. Di Pirro, A. Drago, A. Esposito, M. Ferrario, L. Ficcadenti, D. Filippetto, V. Fusco, A. Gallo, G. Gatti, A. Ghigo, M. Incurvati, C. Ligi, F. Marcellini, M. Migliorati, A. Mostacci, L. Palumbo, L. Pellegrino, M.A. Preger, R. Ricci, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stecchi, A. Stella, F. Tazzioli, C. Vaccarezza, M. Vescovi, C. Vicario INFN/LNF, Frascati (Roma) F. Alessandria, A. Bacci, I. Boscolo, F. Broggi, S. Cialdi, C. De Martinis, D. Giove, C. Maroli, M. Mauri, V. Petrillo, M. Rome, A.R. Rossi, L. Serafini INFN-Milano, Milano L. Catani, E. Chiadroni, A. Cianchi, E. Gabrielli, S. Tazzari INFN-Roma II, Roma F. Ciocci, G. Dattoli, A. Dipace, A. Doria, G.P. Gallerano, L. Giannessi, E. Giovenale, G. Messina, P.L. Ottaviani, S. Pagnutti, L. Picardi, M. Quattromini, A. Renieri, G. Ronci, C. Ronsivalle, M. Rosetti, E. Sabia, M. Sassi, A. Torre, A. Zucchini ENEA C.R. Frascati, Frascati (Roma) A. Perrone INFN-Lecce, Lecce S. Reiche, J.B. Rosenzweig, G. Travish UCLA, Los Angeles, California
	The SPARC Project is starting the commissioning of its photo-injector. RF gun, RF sources, RF network and control, power supplies, emittance meter, beam diagnostics and control to measure the RF gun beam are installed. The photocathode drive laser has been characterized in terms of pulse shape and quality. We expect to conduct beam measurements at RF gun exit in the next future and consequently to start the installation of accelerating sections. The design of the 12 m undulator for the FEL experiment has been completed and the first undulator section out of 6 is under construction: we expect to characterize it at Frascati ENEA laboratory within the next months. SPARC as a facility will host FEL experiments using SASE, seeding and non-linear resonant harmonics. Additional R&D on X-band and S-band structures for velocity bunching are in progress, as well as studies on new photocathode materials and exotic undulator designs. We also present studies on solenoid field defects, beam based alignments, exotic electron bunch production (blow-out of short laser pulses or intensity modulated laser pulses). The possible use of segmented superconducting micro-undulators will be discussed too.

MOPCH030	Production of Coherent X-rays with a Free Electron Laser Based on an Optical Wiggler	laser, radiation, emittance, FEL	113
	V. Petrillo, A. Colzato Universita' degli Studi di Milano, Milano A. Bacci, C. Maroli, L. Serafini INFN-Milano, Milano M. Ferrario INFN/LNF, Frascati (Roma)
	The interaction between high-brightness electron beams and counter-propagating laser pulses produces X rays via Thomson scattering. If the laser source is long enough, the electrons bunch on the scale of the emitted X-ray wavelength and a regime of collective effects establishes. In this case, the FEL instability develops and the system behaves like a FEL based on an optical undulator. Coherent X-rays are irradiated, with a bandwidth thinner than that of the incoherent emission. The emittance of the beam and gradients or irregularities in the laser energy distribution are the principal factors that limit the growth of the X-ray signal. We analyse with a 3-D code the transverse effects in the emission produced by a relativistic electron beam when it is under the action of an optical laser pulse and the X-ray spectra obtained. The scalings typical of the optical wiggler, with very short gain lengths and overall time durations of the process make possible considerable emission also in violation of the Pellegrini criterion for static wigglers. A generalized form of this criterion is validated on the basis of the numerical evidence.

MOPCH034	On a Skeleton CASSINI Ovals Current Undulator	undulator, laser, radiation, free-electron-laser	119
	A.M. Mihalache, V.I.R. Niculescu INFLPR, Bucharest - Magurele V. Babin INOE, Bucharest M.R. Leonovici, C. Stancu Bucharest University, Faculty of Physics, Bucharest-Magurele F. Scarlat Valahia University, Faculty of Sciences, Targoviste
	A new undulator structure for free electron lasers was presented. Current skeleton CASSINI ovals produced magnetic fields which are spatially periodic. The current structure was in the shape of stacks of modified CASSINI ovals. The current has alternating directions. The magnetic field components for each wire present C2 symmetry. CASSINI undulator transverse cross-section* was approximated by polygons. In cartesian coordinates the Biot-Savart law was analytically evaluated. The magnetic field was mainly transversal and easily adjusted with the current. The versatility of this structure introduces a new type of two beams longitudinal undulator or wiggler design for transverse moments. *Cassini curve; C. Mihu, I.P. Iambor-1989.

MOPCH036	Photocathode Roughness Impact on Photogun Beam Characteristics	emittance, cathode, gun, FEL	121
	T.V. Gorlov MEPhI, Moscow A.M. Tron LPI, Moscow
	Photocathode surface roughness has an impact on photoelectron yield, bunch duration, beam emittance at the exit of femtosecond photogun with an accelerating field that is considered in assumption of quasi-stationary one in the paper. The main problem in investigating the impact is determination of the field near the surface, statistical properties of which are defined through rms values of deviation and slope in profile line of the surface roughness. Developed and created code allows determining the field with relative rms error not worse than 0.001%. The results of the investigation for rms values of roughness and its slope within respectively 500…0 nm and 20…0 degrees are presented and discussed.

MOPCH038	Predicted Parameters of the Second Stage of High Power Novosibirsk FEL	FEL, undulator, simulation, ERL	124
	A.V. Kuzmin, O.A. Shevchenko, N. Vinokurov BINP SB RAS, Novosibirsk
	The first stage of Novosibirsk high power terahertz FEL was successfully put into operation in 2003. The measured parameters of the FEL turned out to be in a good agreement with calculations [2]. The second and the third stages of the FEL are under construction now. The beam energy at the second stage will be about 20 MeV and the wavelength will change in the range 40-80 μm. In this paper we present the design parameters for the second stage FEL. The simulations were carried out with the help of 1-D code based on macroparticles. This code was previously used for the first stage simulations. E. A. Antokhin et al. NIM A528 (2004) p.15-18.**A. V. Kuzmin et al. NIM A543 (2005) p.114-117.

MOPCH040	Simulations for the FEL Test Facility at MAX-lab within EUROFEL	FEL, undulator, simulation, gun	127
	S. Thorin, M. Brandin, S. Werin MAX-lab, Lund M. Abo-Bakr, J. Bahrdt, K. Goldammer BESSY GmbH, Berlin
	Within the EUROFEL project a High Gain Harmonic Generation Free Electron Laser will be constructed at MAX-lab in collaboration with BESSY. The electron bunches will be created in the existing MAX-lab injector and transported to the inside of the MAX II ring where the FEL undulators will be located. To predict FEL performance and stability, simulations of the photo injector, linac, recirculator, transport and undulator sections as well as start to end simulations have been carried out.

MOPCH042	Progress in the Design of a Two-Frequency RF Cavity for an Ultra-Low Emittance Pre-Accelerated Beam	emittance, injection, cathode, coupling	133
	J.-Y. Raguin, A. Anghel, R.J. Bakker, M. Dehler, R. Ganter, C. Gough, S. Ivkovic, E. Kirk, F. Le Pimpec, S.C. Leemann, K.L. Li, M. Paraliev, M. Pedrozzi, L. Rivkin, V. Schlott, A.F. Wrulich PSI, Villigen
	Today most of the X-rays Free-Electron Laser projects are based on state of the art RF guns, which aim at a normalized electron beam emittance close to 1 mm$·$mrad. In this paper we report on the progress made at PSI towards a hybrid DC + RF Low Emittance Gun (LEG) capable of producing a beam with an emittance below 0.1 mm.mrad. To reduce the intrinsic thermal emittance at the LEG cathode the electrons are extracted from nano-structured field-emitters. A gun test facility is under construction wherein after emission the beam is accelerated up to 500 keV in a diode before being injected and accelerated in a two-frequency 1.5-cell RF cavity. The fast acceleration in the diode configuration allows to minimize the emittance dilution due to the strong space charge forces. The two-frequency RF structure is optimized to limit the emittance blow-up due to the non-linearity of the RF field.

MOPCH043	An Optimization Study for an FEL Oscillator at TAC Test Facility	FEL, radiation, undulator, laser	136
	Ö.M. Mete, Ö. Karsli, O. Yavas Ankara University, Faculty of Engineering, Tandogan, Ankara
	Recently, conceptual design of the Turkic Accelerator Center (TAC) proposal was completed. The main goal of this proposal is a charm factory that consists of a linac-ring type electron-positron collider. In addition, synchrotron radiation from the positron ring and free electron laser from the electron linac are proposed. The project related with this proposal has been accepted by the Turkish government. It is planned that the Technical Design Report of TAC will have been written in the next three years. In this period, an infrared oscillator free electron laser (IR FEL) will be constructed as a test facility for TAC. 20 and 50 MeV electron energies will be used to obtain infrared FEL. The main parameters of the electron linacs, the optical cavities and the FEL were determined. The possible use of obtained laser beam in basic and applied research areas such as biotechnology, nanotechnology, semiconductors and photo chemistry were discussed.

MOPCH045	A Source of Coherent Soft X-ray Radiation Based on High-order Harmonic Generation and Free Electron Lasers	laser, FEL, undulator, simulation	142
	M. Gullans, J.S. Wurtele UCB, Berkeley, California G. Penn, A. Zholents LBNL, Berkeley, California
	We examine a scheme for a Free Electron Laser (FEL) harmonic amplifier seeded by a ~30-nm wavelength signal produced using a process of High-order Harmonic Generation (HHG). The seed is first amplified in an optical klystron from ~100 kW to ~30 MW using a 1 GeV electron beam and then is used for an energy modulation of electrons in the downstream undulator. Subsequently, a 100-MW level of radiation at shorter wavelengths down to 4 nm is obtained by bunching the energy modulated electrons and passing the bunched beam through an undulator tuned to the desired harmonic of 30 nm. We also compare this scheme to a more familiar harmonic cascade FEL by replacing the HHG with an additional stage of harmonic generation.

MOPCH047	Study of the Electron Beam Dynamics in the FERMI @ ELETTRA Linac	emittance, linac, laser, simulation	145
	M. Cornacchia, P. Craievich, S. Di Mitri ELETTRA, Basovizza, Trieste I.V. Pogorelov, J. Qiang, M. Venturini, A. Zholents LBNL, Berkeley, California D. Wang MIT, Middleton, Massachusetts R.L. Warnock SLAC, Menlo Park, California
	A study of the electron beam dynamics in the linac is made within the framework of the design of a free electron laser (FEL) at the Syncrotrone Trieste. A scope of the work includes analysis of two operational scenarios, one with relatively long electron bunches of the order of 1.5 ps and a moderate peak current of 500 A and one with shorter bunches of the order of 0.7 ps and higher peak current of the order of 800 A. In both cases, care has been taken to preserve the slice and projected emittances formed in the photocathode gun injector and to minimize the slice energy spread. The latter goal is accomplished by balancing the onset of the microbunching instability driven by the longitudinal space charge forces and the emission of coherent synchrotron radiation using Landau damping produced by a so-called laser heater. Various analytical techniques and tracking codes have been employed to obtain the reported results. C. Bocchetta, et al., this conference.

MOPCH051	Operation of the First Undulator-based Femtoslicing Source	laser, photon, background, radiation	154
	S. Khan Uni HH, Hamburg K. Holldack, T. Kachel, T. Quast BESSY GmbH, Berlin R. Mitzner Universität Muenster, Physikalisches Institut, Muenster
	At the BESSY II storage ring, a source of sub-100-fs x-ray pulses with tunable polarization and excellent signal-to-background ratio has been constructed in 2004, based on laser-induced energy modulation ("femtoslicing") and subsequent angular separation of the short-pulse x-rays from an elliptical undulator. After commissioning and characterizing the source, short-pulse radiation is now routinely delivered for pump-probe applications. The paper summarizes the results from commissioning and operational experience as well as possible upgrade options. A. Zholents and M. Zoloterev, PRL 76 (1996), 912.

MOPCH053	Towards Sub-picoseconds Electron Bunches: Upgrading Ideas for BESSY II	optics, radiation, focusing, storage-ring	157
	G. Wuestefeld, J. Feikes, P. Kuske BESSY GmbH, Berlin
	Sub-picoseconds bunches were achieved with the BESSY low alpha optics, and their lengths were measured using Fourier Transform spectroscopy. To avoid the coherent synchrotron radiation instability, the current in these short bunches has to be limited to theμampere level. An upgrade of the BESSY II rf gradient to much larger values is suggested to overcome this low current limitation by two orders of magnitude. Intense, picoseconds long bunches could then be achieved already at the regular user optics. The resulting short and very intense electron bunches are useful for generation of short x-ray pulses and powerful THz-radiation. Expected parameters of bunch length and current are discussed. J. Feikes et al. "Sub-Picoseconds Electron Bunches in the BESSY Storage Ring", EPAC'04, Luzerne (Switzerland), July 2004.

MOPCH056	Development of High Brightness Soft X-ray Source Based on Inverse Compton Scattering	laser, background, MCP, scattering	166
	R. Moriyama, Y. Hama, K. Hidume, A. Oshima, T. Saito, K. Sakaue, M. Washio RISE, Tokyo H. Hayano, J. Urakawa KEK, Ibaraki S. Kashiwagi ISIR, Osaka R. Kuroda AIST, Tsukuba, Ibaraki
	Compact soft X-ray source based on inverse compton scattering have been developed at Waseda University. Using 1047nm laser light from Nd:YLF laser scattered off 4.2MeV electron beam generated from a photo-cathode rf-gun, we have already suceeded to generate the soft X-ray. The energy of this x-ray is included in the part of water window, in which absorption of water is much less than that of moleculars that organize a living body. Furthermore, this x-ray source has other features such as short pulse, proportional mono-energy and energy variableness. Because of these tures, the application to the biological microscope have been expected. However, the flux of x-ray is not satisfied for the biological microscope application. Therefore, to multiply a soft X-ray flux, we utilized multi-pass amplifier for the laser light and improved a collision chamber. In this conference, we will report the experimental results and future plans.

MOPCH057	The Design of a 1.8 keV Compton X-ray Generator for a SC RF Linac at KAERI	laser, photon, linac, brilliance	169
	A.V. Bondarenko, S.V. Miginsky BINP SB RAS, Novosibirsk Y.H. Han, Y.U. Jeong, B.C. Lee, S. H. Park KAERI, Daejon
	A quasi-monochromatic X-ray source based on the KAERI SC linac system has been designed and is being manufactured now. A 10 MeV 10 mA electron beam together with a 20 W 1.06 ?m laser beam will be used for 1.8 keV Compton X-ray generation with a few percentage of energy spread and 107 photons per second. A simple straight beamline was designed to deliver the electron beam with no degradation of its emittance and energy spread and to focus it to a proper size to produce the desired X-rays. We expect the first demonstration of 1.8 keV Compton X-ray generation in autumn 2006.

MOPCH066	The Conceptual Design of 4GLS at Daresbury Laboratory	linac, radiation, FEL, undulator	181
	J.A. Clarke CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
	4GLS is a novel next generation proposal for a UK national light source to be sited at Daresbury Laboratory, based on a superconducting energy recovery linac (ERL) with both high average current photon sources (undulators and bending magnets) and three high peak current free electron lasers. Key features are a high gain, seeded FEL amplifier to generate XUV radiation and the prospect of advanced research arising from unique combinations of sources with femtosecond pulse structure. The conceptual design is now completed and a CDR recently published. The 4GLS concept is summarised, highlighting how the significant design challenges have been addressed, and the project status and plans explained.

MOPCH069	Lattice Design for the Fourth Generation Light Source at Daresbury Laboratory	linac, FEL, laser, undulator	184
	B.D. Muratori, M.A. Bowler, H.L. Owen, S.L. Smith CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire S.V. Miginsky BINP SB RAS, Novosibirsk
	The proposed Fourth Generation Light Source (4GLS) has three electron transport paths, an energy recovery loop containing the main linac, IDs and a VUV-FEL, a separate branch after the main linac for an XUV-FEL and a transport path for an IR-FEL. The first two present major challenges in lattice design. The energy recovery loop will be fed by a high average current gun, with bunches of charge of about 80 pC. High charge (1nC) bunches from a high brightness gun will be accelerated prior to the main linac and split into the XUV-FEL branch using energy separation after the main linac. We present a lattice design and results from numerical modelling of the electron bunch transport. The requirements of the machine are short bunches, a small emittance for both branches and an overall topology which gives a reasonable dimension for the building. Different transport and compression schemes were assessed to meet these requirements whilst balancing the disruptive effects of longitudinal and transverse space charge, CSR, wakefields and BBU. Investigations into all of these instabilities are summarized together with other transport issues and the resulting requirements on all IDs.

MOPCH070	The Status of the Daresbury Energy Recovery Prototype Project	gun, ERLP, linac, diagnostics	187
	D.J. Holder, J.A. Clarke, P.A. McIntosh, M.W. Poole, S.L. Smith CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire N. Bliss CCLRC/DL, Daresbury, Warrington, Cheshire E.A. Seddon CCLRC/DL/SRD, Daresbury, Warrington, Cheshire
	The major component of the UK's R&D programme towards an advanced energy recovery linac-based light source facility is a 35 MeV technology demonstrator called the energy recovery linac prototype (ERLP). This is based on a combination of a DC photocathode electron gun, a superconducting linac operated in energy recovery mode and an IR FEL. The current status of the of this project is presented, including the construction and commissioning progress and plans for the future exploitation of this scientific and technical R&D facility.

MOPCH074	Layout of an Accumulator and Decelerator Ring for FAIR	antiproton, pick-up, injection, kicker	199
	P. Beller, K. Beckert, C. Dimopoulou, A. Dolinskii, F. Nolden, M. Steck, J. Yang GSI, Darmstadt
	Antiproton physics and experiments with rare isotope beams are major research fields at FAIR. Antiproton physics requires the accumulation of high intensity antiproton beams. The accumulation of up to 10¹¹ antiprotons at 3 GeV is foreseen. This will be accomplished by the combination of the collector ring CR for stochastic precooling and the specialized accumulator ring RESR. The accumulation scheme in the RESR is based on the usage of a stochastic cooling system. The requirements of this cooling system strongly affect the magnetic structure of the RESR. For experiments with short-lived rare isotope beams the RESR serves the task of fast deceleration. Precooled rare isotope beams will be injected at 740 MeV/u and then decelerated to energies between 100 and 400 MeV/u in less than 1 s. This contribution presents the ring design and lattice studies relevant for both tasks of the ring as well as a description of the antiproton accumulation scheme.

MOPCH075	Internal Target Effects in the ESR Storage Ring with Cooling	target, simulation, ion, storage-ring	202
	V. Gostishchev, K. Beckert, P. Beller, C. Dimopoulou, A. Dolinskii, F. Nolden, M. Steck GSI, Darmstadt I.N. Meshkov, A.O. Sidorin, A.V. Smirnov, G.V. Trubnikov JINR, Dubna, Moscow Region
	The accurate description of beam-target effects is important for the prediction of operation conditions in terms of high luminosity and beam quality in the FAIR facility at GSI. Numerical models have been developed to evaluate beam dynamics in ion storage rings, where strong cooling in combination with a dense target is applied. First systematic benchmarking experiments were carried out at the existing ESR storage ring at GSI. The influence of the internal target on the beam parameters is demonstrated. Comparison of experimental results with simple models describing the energy loss of the beam particles in the target as well as with more sophisticated simulations with the BETACOOL code will be given.

MOPCH080	Design of the NESR Storage Ring for Operation with Ions and Antiprotons	ion, antiproton, storage-ring, injection	217
	M. Steck, K. Beckert, P. Beller, C. Dimopoulou, A. Dolinskii, F. Nolden, J. Yang GSI, Darmstadt
	The New Experimental Storage Ring (NESR) of the FAIR project has two major modes of operation. These are storage of heavy ion beams for internal experiments and deceleration of highly charged ions and antiprotons before transfer into a low energy experimental area. The heavy ion beams can be either stable highly charged ions or rare isotope beams at an energy of 740 MeV/u selected in a magnetic separator. The antiprotons come with an energy of 3 GeV from the production target, they are pre-cooled and accumulated in a storage ring complex. The magnetic structure of the NESR has been optimized for large transverse and longitudinal acceptance by detailed dynamic aperture calculations. This will allow storage of multi-component beams with a large spread of charge to mass ratio, corresponding to a large spread in magnetic rigidity. Highest phase space density of the stored beams is provided by an electron cooling system, which for ions covers the full energy range and for antiprotons allows intermediate cooling during the deceleration process. For experiments with short-lived isotopes the cooling time and the time of deceleration will be optimized to a few seconds.

MOPCH084	From COSY to HESR	target, COSY, proton, antiproton	226
	D. Prasuhn, J. Dietrich, A. Lehrach, B. Lorentz, R. Maier, H. Stockhorst FZJ, Jülich
	The High Energy Storage Ring (HESR) at the proposed Facility for Antiproton and Ion Research (FAIR) puts strong demands on quality and intensity of the stored antiproton beam in the presence of thick internal targets. The existing synchrotron and storage ring COSY in Juelich can be seen as a smaller model of the HESR. In this paper we will discuss possible benchmarking experiments at COSY, involving effects like beam cooling, target heating, intra-beam scattering, etc. The aim of these experiments is to support the design work for the HESR and ensure that the specified beam conditions can be achieved.

MOPCH088	Ion Cooler Storage Ring, S-LSR	laser, ion, proton, beam-cooling	237
	A. Noda, S. Fujimoto, M. Ikegami, T. Shirai, H. Souda, M. Tanabe, H. Tongu Kyoto ICR, Uji, Kyoto H. Fadil, M. Grieser MPI-K, Heidelberg T. Fujimoto, S.I. Iwata, S. Shibuya AEC, Chiba I.N. Meshkov, I.A. Seleznev, A.V. Smirnov, E. Syresin JINR, Dubna, Moscow Region K. Noda NIRS, Chiba-shi
	Ion cooler and storage ring, S-LSR has been constructed. Its beam commissioning has been successfully performed since October, 2005 and electron beam cooling for 7 MeV proton beam has been performed with both flat and hollow spatial distributions. Effect of relative velocity sweep between electron and ion beams on the cooling time* has been confirmed. Based on the success to create the peaks in the energy spectrum of laser-produced ions, injection of laser-produced ions into S-LSR after rotation in the longitudinal phase space by an RF cavity synchronized to the pulse laser is under planning in order to apply electron cooling for such real laser produced hot ions. Three dimensional laser cooling satisfying the condition of 'tapered cooling' is also under investigation. 24Mg+ ions are to be laser-cooled only in the 'Wien Filter' in order to be cooled down to the appropriate energy according to their horizontal positions*. In parallel with the computer simulation, construction of the laser cooling system with use of ring dye laser accompanied with the second harmonics generator is now underway. H. Fadil et al. Nucl. Instr. & Meth. in Phys. Res. A517, 1-8 (2004).**A. Noda and M. Grieser, Beam Science and Technology, 9, 12-15 (2005).

MOPCH096	LEIR Lattice	injection, quadrupole, optics, lattice	261
	J. Pasternak, P. Beloshitsky, C. Carli, M. Chanel CERN, Geneva
	The Low Energy Ion Ring (LEIR) is a low energy ion cooling and accumulation ring and serves to compress long ion pulses from Linac 3 into high density bunches suitable for LHC ion operation. Issues of the LEIR lattice are to fulfil all constraints with a small number of quadrupoles and compensations of perturbations due to an electron cooler and gradients seen by the beam in the bending magnets during the ramp. Furthermore, experimental investigations via orbit reponse measurements will be reported.

MOPCH102	A Straight Section Design in RHIC to Allow Heavy Ion Electron Cooling	interaction-region, RHIC, dipole, quadrupole	279
	D. Trbojevic, J. Kewisch, W.W. MacKay, T. Roser, S. Tepikian BNL, Upton, Long Island, New York
	The Relativistic Heavy Ion Collider (RHIC) has been continuously producing exciting results. One of the major luminosity limitations of the present collider is the intra beam scattering. A path towards the higher luminosities requires cooling of the heavy ion beams. Two projects in parallel electron and stochastic cooling are progressing very well. To allow interaction between electrons and the RHIC beams it is necessary to redesign one of the existing interaction regions in RHIC to allow for the longer straight section with fixed and large values of the betatron functions. We present a new design of the interaction region for the electron cooling in RHIC.

MOPCH132	Coupled Maps for Electron and Ion Clouds	ion, simulation, RHIC, proton	354
	U. Iriso CELLS, Bellaterra (Cerdanyola del Vallès) S. Peggs BNL, Upton, Long Island, New York
	Contemporary electron cloud models and simulations reproduce second order phase transitions, in which electron clouds grow smoothly beyond a threshold from "off" to "on". In contrast, some locations in the Relativistic Heavy Ion Collider (RHIC) exhibit first order phase transition behaviour, in which electron cloud related outgassing rates turn "on" or "off" precipitously. This paper presents a global framework with a high level of abstraction in which additional physics can be introduced in order to reproduce first (and second) order phase transitions. It does so by introducing maps that model the bunch-to-bunch evolution of coupled electron and ion clouds. This results in simulations that run several orders of magnitude faster, reproduce first order phase transitions, and show hysteresis effects. Coupled maps also suggest that additional dynamical phases (like period doubling, or chaos) could be observed.

MOPCH133	An Analytic Calculation of the Electron Cloud Linear Map Coefficient	simulation, LHC, RHIC, heavy-ion	357
	U. Iriso CELLS, Bellaterra (Cerdanyola del Vallès) S. Peggs BNL, Upton, Long Island, New York
	The evolution of the electron density during multibunch electron cloud formation can often be reproduced using a bunch-to-bunch iterative map formalism. The coefficients that parameterize the map function are readily obtained by fitting to results from compute-intensive electron cloud simulations. This paper derives an analytic expression for the linear map coefficient that governs weak cloud behaviour from first principles. Good agreement is found when analytical results are compared with linear coefficient values obtained from numerical simulations. This analysis is useful in predicting thresholds beyond which electron cloud formation occurs, and thus in determining safety regions in parameter space where an accelerator can be operated without creating electron clouds. The formalism explicitly shows that the multipacting resonance condition is not a sine qua non for electron cloud formation.

MOPCH134	Electron-impact Desorption at the RHIC Beam Pipes	RHIC, injection, vacuum, BNL	360
	U. Iriso, U. Iriso CELLS, Bellaterra (Cerdanyola del Vallès) W. Fischer BNL, Upton, Long Island, New York
	The electron induced molecular desorption coefficient of a material provides the number of molecules released when an electron hits its surface. This coefficient changes as a function of the material, energy of the electrons, surface status, etc. In this paper, this coefficient is inferred analyzing electron detector and pressure gauge signals during electron clouds at the Relativistic Heavy Ion Collider (RHIC) beam pipes. The evolution of the electron-impact desorption coefficient after weeks of electron bombardment is followed for both baked and unbaked stainless steel chambers, evaluating the feasibility of the scrubbing effect. Measurements of an energy spectrum during multipacting conditions are shown, and the final results are compared with laboratory simulations.

MOPCH135	Benchmarking Electron Cloud Data with Computer Simulation Codes	simulation, LEFT, RHIC, BNL	363
	U. Iriso CELLS, Bellaterra (Cerdanyola del Vallès) G. Rumolo CERN, Geneva
	Saturated electron flux and time decay of the electron cloud are experimentally inferred using many electron detector datasets at the Relativistic Heavy Ion Collider (RHIC). These results are compared with simulation results using two independent electron cloud computer codes, CSEC and ECLOUD. Simulation results are obtained over a range of different values for 1) the maximum Secondary Electron Yield (SEY), and 2) the electron reflection probability at zero energy. These results are used to validate parameterization models of the SEY as a function of the electron energy.

MOPCH147	Developments in Conditioning Procedures for the TTF-III Power Couplers	vacuum, DESY, controls, monitoring	399
	H. Jenhani, T. Garvey, P. Lepercq, M. Omeich, C.P. Prevost, V. Variola LAL, Orsay
	Despite extensive experience in many laboratories on power conditioning of couplers for RF superconducting accelerators, it is still not a well understood procedure and can produce many unpredictable phenomena. There remains considerable interest in reducing the power coupler conditioning time necessary for superconducting linear accelerators. This paper presents studies of optimisation of the conditioning procedure for the couplers intended for use on the European XFEL project.

MOPCH148	First RF Tests in the HoBiCaT Superconducting Test Facility at BESSY	vacuum, TESLA, cryogenics, controls	402
	O. Kugeler, W. Anders, J. Borninkhof, H.G. Hoberg, S. Klauke, J. Knobloch, M. Martin, G. Mielczarek, A. Neumann, D. Pflückhahn, S. Rotterdam, M. Schuster, T. Westphal BESSY GmbH, Berlin
	In preparation for the construction of the BESSY-FEL User Facility, BESSY recently completed the installation of the HoBiCaT cryogenic test facility for superconducting RF (SRF) TESLA cavity units, including all ancillary devices (helium tank, input coupler, tuner, magnetic shielding). It is designed to house two such units in a configuration similar to that envisaged for the superconducting CW linac of the BESSY FEL. Commissioning of the facility is now complete and the first TTF-III RF coupler and cavity unit have been tested. In particular, the complete production, cleaning and assembly of the cavity unit was carried out by industry. These tests thus serve as a first step at qualifying industrial partners for series production of such systems, which will be essential for the future construction of SRF based light sources. Results will be presented.

MOPCH158	HIPPI Triple-spoke Cavity Design	simulation, gun, vacuum, resonance	427
	E. Zaplatin, M. Pap, R. Tölle FZJ, Jülich
	In the frames of the European project of High Intensity Pulsed Proton Injector (HIPPI) the 352 MHz, beta=0.48 triple-spoke cavity is under development and will be built at the research center FZJ in Juelich. The criteria and results of the cavity RF and structural analyses are presented.

MOPCH160	A Beam-based High Resolution Phase Imbalance Measurement Method for the ILC Crab Cavities	dipole, positron, linear-collider, single-bunch	433
	A. Kalinin, L. Ma, R.J. Smith CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
	A high resolution method of RF phase adjustment and test is proposed for the Crab Cavity system of the ILC. The method is based on beam as ultimate test instrument. To measure phase imbalance in the pair of crab cavities (<0.02deg at 1.3GHz is required), a low energy (~1GeV) beam is used. A bunch center-of-mass trajectory through the cavities spaced (n+1/2) RF wavelengths and excited as in the case of the ILC, is a straight line for phase-balanced cavities and gets a kick when unbalanced. The kick is measured by two spaced BPMs with reference to the initial trajectory angle measured by two other BPMs. The method is insensitive to a bunch arrival time jitter and RF phase Common Mode jitter. A prototype of the test bench based on the method, is proposed. Using a 10MeV beam, two simple dipole cavities and low RF power, the prototype can be utilized for mastering high resolution measurements, for adjustment and tests of low level electronics of the Crab Cavity system and RF systems of XFEL ERLs as well. The phase resolution of the prototype is estimated as 0.01deg and the amplitude resolution as 0.01%.

MOPCH162	RF Requirements for the 4GLS Linac Systems	linac, ERL, acceleration, controls	439
	P.A. McIntosh, C.D. Beard, D.M. Dykes, A.J. Moss CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
	The 4GLS facility at Daresbury will combine energy recovery linac (ERL) and free electron laser (FEL) technologies to deliver a suite of naturally synchronised state-of-the-art sources of synchrotron radiation and FEL radiation covering the terahertz (THz) to soft X-ray regimes. CW-mode operation at high acceleration gradients are needed for the various 4GLS accelerator systems and here is where Superconducting Radio Frequency (SRF) cavities excel. Since resistive losses in the cavity walls increase as the square of the accelerating voltage, conventional copper cavities become uneconomical when the demand for high CW voltage grows with particle energy requirements. After accounting for the refrigeration power needed to provide the liquid helium operating temperature, a net power gain of several hundred remains for SRF over conventional copper cavities. This paper details the RF requirements for each of the SRF accelerating stages of the 4GLS facility, outlining techniques necessary to cope with CW-mode operation and HOM power generation.

MOPCH171	ILC Coaxial Blade Tuner	TTF, DESY, LEFT, linear-collider	466
	C. Pagani, A. Bosotti, P. Michelato, N. Panzeri, R. Paparella, P. Pierini INFN/LASA, Segrate (MI)
	A coaxial (blade) tuner solution has been developed for the compensation of the Lorentz force detuning of the superconducting cavities under the high gradient pulsed operation foreseen for ILC operation. The device is based on prototypes successfully tested at DESY in 2002 both on CHECHIA and on the superstructures inserted in the TTF string. During both tests the blade tuner performed as expected in terms of stiffness, frequency sensitivity and tuning capabilities. An improvement of the tuner characteristics has been designed by the integration of fast tuning capabilities by means of piezo-ceramic element. Two prototipes of the new INFN coaxial piezo blade tuner have just been manufactured and they will be tested at DESY and BESSY after the cavity integration. In this paper the blade tuner design and main characteristics are presented, together with the early interpretation of the cold test results.

MOPCH177	Status of HOM Load for the Cornell ERL Injector	ERL, linac, damping, emittance	478
	V.D. Shemelin, B. Gillett Cornell University, Ithaca, New York P. Barnes, M. Liepe, V. Medjidzade, H. Padamsee, G.R. Roy, J. Sears Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
	The HOM load for the injector of the Energy Recovery Linac at Cornell University is proposed to work at a temperature of 80 K. The anticipated absorbed power of the load is up to 200 W. Versions with inner diameter of 78 and 106 mm are under development. Two different kinds of ferrites and a lossy ceramic are chosen as RF absorbers for the load to cover a wide frequency range. Measurements of electromagnetic properties of absorbing materials have been performed in a frequency range from 1 to 40 GHz. The engineering design of the load is ready and technological issues of brazing the absorbing tiles and cooling have been solved. Brazing quality is controlled by IR thermograms. First warm measurements of a prototype load are expected this summer.

MOPCH184	Plasma Treatment of Bulk Niobium Surfaces for SRF Cavities	plasma, cathode, ion, controls	493
	L. Vuskovic, S. Popovic, M. Raskovic ODU, Norfolk, Virginia L. Godet, S.B. Radovanov VSEA, Gloucester, Maryland H.L. Phillips, A-M. Valente-Feliciano Jefferson Lab, Newport News, Virginia
	Cavity surface preparation has been one of the major problems in superconducting radio-frequency (SRF) accelerator technology. Accelerator performance depends directly on the physical and chemical characteristics at the SRF cavity surface. The primary objective of our work is to explore the effects of various types of electric discharge plasmas to minimize surface roughness and eliminate or minimize deterioration of cavity properties by oxygen, hydrogen and other chemical contaminants. To optimize the plasma etching process, samples of bulk Nb are being exposed to three types of electrical discharge in various experimental set-ups. The surface quality obtained by the three methods was compared with samples treated with buffer chemical polishing techniques. Surface comparisons are made using digital imaging (optical) microscopy, scanning electron microscopy, and atomic force microscopy. In preliminary tests, samples compared with those treated conventionally have shown comparable or superior properties. Tests have also shown that surface quality varies with plasma conditions and their optimization to obtain the best SRF cavity surface is a major goal of the ongoing work.

MOPCH192	Operation of a Helium Cryogenic System for a Superconducting Cavity in an Electron Storage Ring	cryogenics, controls, superconducting-magnet, storage-ring	511
	F. Z. Hsiao, S.-H. Chang, W.-S. Chiou, H.C. Li NSRRC, Hsinchu
	A 500 MHz superconducting cavity maintaining the energy of electrons in the storage ring of TLS light source started from the year 2005. A helium system dedicated to keep the niobium cavity at 4.5 K has begun its operation since the year 2003. The cryogenic system provides maximum refrigeration of 469 W or liquefaction rate of 134 l/hr. The constraint from the superconducting cavity leads to specific features of the cryogenic system. This paper presents the operation of the cryogenic system as the superconducting cavity at different conditions. The interaction in between the cryogenic system and the superconducting cavity and the constraints on the starting and shutdown of the cryogenic system are indicated.

MOPLS021	Beam Pipe Desorption Rate in RHIC	ion, RHIC, vacuum, beam-losses	583
	H. Huang, W. Fischer, P. He, H.-C. Hseuh, U. Iriso, V. Ptitsyn, D. Trbojevic, J. Wei, S.Y. Zhang BNL, Upton, Long Island, New York
	Increase of beam intensity in RHIC has caused several decades of pressure rises in the warm sections during operation. This has been a major factor limiting the RHIC luminosity. About 250 meters of NEG coated beam pipes have been installed in many warm sections to ameliorate this problem. Beam ion induced desorption is one possible cause of pressure rises. A series beam studies in RHIC has been dedicated to estimate the desorption rate of various beam pipes (regular and NEG coated) at various warm sections. Correctors were used to generate local beam losses and consequently local pressure rises. The experiment results are presented and analyzed in this paper.

MOPLS025	Experience in Reducing Electron Cloud and Dynamic Pressure Rise in Warm and Cold Regions in RHIC	emittance, proton, RHIC, luminosity	595
	S.Y. Zhang, L. Ahrens, J.G. Alessi, M. Bai, M. Blaskiewicz, P. Cameron, R. Connolly, K.A. Drees, W. Fischer, J. Gullotta, P. He, H.-C. Hseuh, H. Huang, R.C. Lee, V. Litvinenko, W.W. MacKay, C. Montag, T. Nicoletti, B. Oerter, F.C. Pilat, V. Ptitsyn, T. Roser, T. Satogata, L. Smart, L. Snydstrup, S. Tepikian, P. Thieberger, D. Trbojevic, J. Wei, K. Zeno BNL, Upton, Long Island, New York
	Significant improvement has been achieved for reducing electron cloud and dynamic pressure rise at RHIC over several years; however, there remain to be factors limiting luminosity. The large scale application of non-evaporable getter (NEG) coating in RHIC has been proven effective in reducing electron multipacting and dynamic pressure rise. This will be reported together with the study of the saturated NEG coatings. Since beams with increased intensity and shorter bunch spacing became possible in operation, the electron cloud effects on beam, such as the emittance growth,are an increasing concern. Observations and studies are reported. We also report the study results relevant to the RHIC electron cloud and pressure rise improvement, such as the effect of anti-grazing ridges on electron cloud in warm sections, and the effect of pre-pumping in cryogenic regions.

MOPLS030	Recent Progress of KEKB	luminosity, KEKB, optics, vacuum	610
	Y. Funakoshi KEK, Ibaraki
	We summarize the machine operation of KEKB during the past one year, focusing on progress for this period.

MOPLS038	Beam Energy Calibration in Experiment on Precise Tau Lepton Mass Measurement at VEPP-4M with KEDR Detector	energy-calibration, resonance, lepton, polarization	625
	A. Bogomyagkov, V.E. Blinov, S. Karnaev, V. Kiselev, E.V. Kremyanskaya, E. Levichev, O.I. Meshkov, S.I. Mishnev, I. Morozov, N.Yu. Muchnoi, S.A. Nikitin, I.B. Nikolaev, A.G. Shamov, D.N. Shatilov, E.A. Simonov, A.N. Skrinsky, V.V. Smaluk, Yu.A. Tikhonov, G.M. Tumaikin, V.N. Zhilich BINP SB RAS, Novosibirsk
	Experiment on mass measurement of tau lepton requires an absolute energy calibration. The resonant depolarization technique is used for most accurate (1 keV) but once at a time energy calibration. The measured energy is used for calibration of the germanium detector for Compton backscattering energy monitoring. The developed Compton backscattering facility allows continuous energy monitoring with accuracy of 50 keV for 10 minutes of data acquisition. The tau lepton threshold is in the vicinity of integer spin resonance, which minimizes polarization lifetime in the presence of vertical orbit distortions. Therefore, spin matching of the VEPP-4M is required. The achieved lifetime is sufficient for absolute energy calibration.

MOPLS043	Studies of the Beam-beam Interaction at CESR	positron, optics, injection, lattice	637
	J.A. Crittenden Cornell University, Department of Physics, Ithaca, New York M.G. Billing CESR-LEPP, Ithaca, New York
	The Cornell Electron Storage Ring facility operates 2-GeV multi-bunch electron and positron beams in a single beam-pipe. Electrostatic separators are used to separate the two counter-rotating beams at the parasitic crossings. When the beam energy was lowered from 5 GeV in 2003, the strength of the beam-beam interaction became a more important factor in beam-current limitations, resulting in extensive experimental and calculational studies of their characteristics. The CESR lattice design procedure has been modified recently to account explicitly for their dynamic consequences. We describe our modelling of the beam-beam interaction, experimental validation techniques, and investigations into compensation strategies.

MOPLS044	Luminosity Variations along Bunch Trains in PEP-II	luminosity, synchrotron, quadrupole, positron	640
	F.-J. Decker, M. Boyes, W.S. Colocho, A. Novokhatski, M.K. Sullivan, J.L. Turner, S.P. Weathersby, U. Wienands, G. Yocky SLAC, Menlo Park, California
	In spring of 2005 after a long shut-down, the luminosity of the B-Factory PEP-II decreased along the bunch trains by about 25-30%. There were many reasons studied which could have caused this performance degradation, like a bigger phase transient due to an additional RF station in the Low-Energy-Ring (LER), bad initial vacuum, electron cloud, chromaticity, steering, dispersion in cavities, beam optics, etc. The initial specific luminosity of 4.2 sloped down to 3.2 and even 2.8 for a long train (typical: 130 of 144), later in the run with higher currents and shorter trains (65 of 72) the numbers were more like 3.2 down to 2.6. Finally after steering the interaction region for an unrelated reason (overheated BPM buttons) and the consequential lower luminosity for two weeks, the luminosity slope problem was mysteriously gone. Several parameters got changed and there is still some discussion about which one finally fixed the problem. Among others, likely candidates are: the LER betatron function in x at the interaction point got reduced, making the LER x stronger, dispersion reduction in the cavities, and finding and fixing a partially shorted magnet.

MOPLS045	Achieving a Luminosity of 10³⁴/cm²/s in the PEP-II B-factory	luminosity, injection, positron, beam-beam-effects	643
	J. Seeman, J. Browne, Y. Cai, W.S. Colocho, F.-J. Decker, M.H. Donald, S. Ecklund, R.A. Erickson, A.S. Fisher, J.D. Fox, S.A. Heifets, R.H. Iverson, A. Kulikov, A. Novokhatski, V. Pacak, M.T.F. Pivi, C.H. Rivetta, M.C. Ross, P. Schuh, K.G. Sonnad, M. Stanek, M.K. Sullivan, P. Tenenbaum, D. Teytelman, J.L. Turner, D. Van Winkle, M. Weaver, U. Wienands, W. Wittmer, M. Woodley, Y.T. Yan, G. Yocky SLAC, Menlo Park, California M.E. Biagini INFN/LNF, Frascati (Roma) W. Kozanecki CEA, Gif-sur-Yvette
	For the PEP-II Operation Staff: PEP-II is an asymmetric e⁺e^- collider operating at the Upsilon 4S and has recently set several performance records. The luminosity has exceeded 1x10³⁴/cm²/s and has delivered an integrated luminosity of 728/pb in one day. PEP-II operates in continuous injection mode for both beams, boosting the integrated luminosity. The peak positron current has reached 2.94 A and 1.74 A of electrons in 1732 bunches. The total integrated luminosity since turn on in 1999 has reached over 333/fb. This paper reviews the present performance issues of PEP-II and also the planned increase of luminosity in the near future to over 2 x 10³⁴/cm²/s. Upgrade details and plans are discussed.

MOPLS054	On Increasing the HERA Luminosity	luminosity, proton, lepton, optics	667
	Y.A. Kot, F.J. Willeke DESY, Hamburg
	The luminosity of the HERA lepton proton collider is limited in part by the bunch length of the protons of 20cm. This limitation is expected to be removed by the installation of a new damper system which will control longitudinal coupled bunch instabilities of the proton beam and avoid the bunch lengthening of a factor of two. This opens the possibility for increasing the luminosity HERA since the beta functions at IP for both leptons and protons can be lowered by about 20% without noticeable reduction of the corresponding luminosity by the so-called hour-glass effect. The beam spot size can be further reduced if the beam-beam focusing of the leptons (dynamic beta) at IP is increased by softening the rigorous beam beam-beta beat compensation which is accomplished by proper phasing of the two IP's. Unfortunately the non-linear chromaticity compensation would be weakened as well, which will cause an enhancement of the synchro-betatron resonances and may lead to poor lifetime and poor background conditions. Therefore, the non-linear chromaticity needs to be reduced by means of a more complex scheme of chromaticity compensating sextupole magnets.

MOPLS056	QCD Explorer Proposal: E-linac versus E-ring	LHC, collider, CLIC, LEP	673
	H. Karadeniz TAEK, Ankara S. Sultansoy Gazi University, Faculty of Science and Arts, Ankara
	TeV center of mass energy lepton-hadron collider is necessary both to clarify fundamental aspects of strong interactions and for adequate interpretation of the LHC data. Recently proposed QCD Explorer utilizes the energy advantage of the LHC proton and ion beams, which allows the usage of relatively low energy electron beam. Two options for the LHC based ep collider are possible: construction of a new electron ring in the LHC tunnel or construction of an e-linac tangentially to the LHC. In the latter case, which seems more acceptable for a number of reasons, two options are under consideration for electron linac: the CLIC technology allows shorter linac length, whereas TESLA technology gives higher luminosity.

MOPLS058	eRHIC - Future Machine for Experiments on Electron-ion Collisions	proton, luminosity, ion, positron	676
	V. Ptitsyn, J. Beebe-Wang, I. Ben-Zvi, A.V. Fedotov, W. Fischer, W. Graves, V. Litvinenko, W.W. MacKay, C. Montag, S. Ozaki, T. Roser, S. Tepikian, D. Trbojevic BNL, Upton, Long Island, New York D.P. Barber DESY, Hamburg W.A. Franklin, R. Milner, B. Surrow, C. Tschalaer, E. Tsentalovich, D. Wang, F. Wang, A. Zolfaghari, T. Zwart, J. van der Laan MIT, Middleton, Massachusetts A.V. Otboev, Y.M. Shatunov BINP SB RAS, Novosibirsk
	The paper presents recent developments for the design of the high luminosity electron-ion collider, eRHIC, proposed on the basis of the existing RHIC machine. The goal of eRHIC is to provide collisions of electrons and positrons on ions and protons in the center-of-mass energy range from 30 to 100 GeV. Lepton beams as well as the beam of protons (and, possibly, light ions) should be polarized. Two independent designs are under development, the so-called 'ring-ring' and 'linac-ring' options. The 'ring-ring' option is based on a 10 GeV electron storage ring. The design issues for the 'ring-ring' option are similar to those at existing B-factories. In the 'linac-ring' option, the electron beam is accelerated in a 10 GeV recirculating energy recovery linac. This option may provide higher luminosities (> 1·10³³ cm-2s-1 for e-p collisions), but requires considerable R&D studies for a high current electron polarized source. In order to maximize the collider luminosity, ion ring upgrades, such as electron cooling and ion beam intensity increase, are considered.

MOPLS068	Beam Impact of the ILC Collimators	simulation, LEFT, monitoring, positron	703
	G. Ellwood, R.J.S. Greenhalgh CCLRC/RAL, Chilton, Didcot, Oxon
	Spoilers in the ILC Beam Delivery System are required to survive a minimum of 1-2 direct impacts from each energetic electron or positron bunch of charged particles without failure, in addition to maintaining low geometric and resistive wall wakefields. The transient shock wave resulting from rapid localised beam heating and its implications for spoiler design are studied using ANSYS. The realistic patterns of energy deposition are taken from FLUKA.The results presented quantify uncertainties in the predictions and consider possible options for spoiler jaws for the ILC.

MOPLS069	Development of a Superconducting Helical Undulator for the ILC Positron Source	undulator, positron, linear-collider, CERN	706
	Y. Ivanyushenkov, E. Baynham, T.W. Bradshaw, A.J. Brummitt, F.S. Carr, J. Rochford CCLRC/RAL, Chilton, Didcot, Oxon I.R. Bailey, D.P. Barber, J.A. Clarke, J.B. Dainton, O.B. Malyshev, D.J. Scott, B.J.A. Shepherd Cockcroft Institute, Warrington, Cheshire P. Cooke, L.I. Malysheva Liverpool University, Science Faculty, Liverpool G.A. Moortgat-Pick CERN, Geneva
	An undulator positron source has been recently selected by the International Linear Collider (ILC) community as a baseline. For the ILC a helical undulator capable of producing 10 MeV photons and with a period as close as possible to 10 mm is required. The HeliCal collaboration in the UK is looking at the merits of both permanent magnet and superconducting technologies for the design of a helical undulator. For the superconducting option, several prototypes have been built and tested. This paper details the design, construction and test results of the first superconducting prototypes.

MOPLS071	TDR Measurements in support of ILC Collimator Studies	impedance, simulation, synchrotron, SLAC	712
	C.D. Beard, P.A. Corlett, A.J. Moss, J.H.P. Rogers CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire R.M. Jones Cockcroft Institute, Warrington, Cheshire
	In this report the outcome of the "wire method" cold test, experimental results and their relevance toward the ILC set-up is considered. A wire is stretched through the centre of a vessel along the axis that the electron beam would take, and a voltage pulse representing the electron bunch is passed along the wire. The parasitic mode loss parameter from this voltage can then be measured. The bunch length for the ILC is 0.3mm, requiring a pulse rise time of ~1ps. The fastest rise time available for a time domain reflectrometry (TDR) scope is ~10ps. Reference vessels have been examined to evaluate the suitability of the test gear at comparable bunch structures to the ILC.

MOPLS072	Status of the HeLiCal Contribution to the Polarised Positron Source for the International Linear Collider	undulator, positron, photon, polarization	715
	J.A. Clarke, O.B. Malyshev, D.J. Scott CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire I.R. Bailey, P. Cooke, J.B. Dainton, L.I. Malysheva Liverpool University, Science Faculty, Liverpool D.P. Barber DESY, Hamburg E. Baynham, T.W. Bradshaw, A.J. Brummitt, F.S. Carr, Y. Ivanyushenkov, J. Rochford CCLRC/RAL, Chilton, Didcot, Oxon G.A. Moortgat-Pick Durham University, Durham
	The baseline positron source for the International Linear Collider is a helical undulator-based design, which can generate unprecedented quantities of polarised positrons. A major thrust of the global design in this area is led by the UK-based HeLiCal collaboration. The collaboration takes responsibility for the design and prototyping of the helical undulator itself, which is a highly demanding short period device with very small aperture, and also leads the start to end simulations of the polarised particles to ensure that the high polarisation levels generated are maintained from the source, right through the beam transport systems and up to the interaction point itself. This paper will provide an update on the work of the collaboration, focusing on these two topic areas, and will also discuss future plans.

MOPLS073	Shower Simulations, Comparison of Fluka, Geant4 and EGS4	simulation, radiation, target, SLAC	718
	L. Fernandez-Hernando CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire R.J. Barlow UMAN, Manchester A. Bungau Cockcroft Institute, Warrington, Cheshire L. Keller SLAC, Menlo Park, California N.K. Watson CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
	Computer simulations with different packages (Fluka, Geant4 and EGS4) were run in order to determine the energy deposition of an ILC bunch in a spoiler of specified geometry at various depths. The uncertainty in these predictions is estimated by comparison of their results. Various candidate spoiler designs (geometry, material) are studied. These shower simulations can be used as inputs to thermal and mechanical studies using programs such as ANSYS.

MOPLS075	Progress towards Crab Cavity Solutions for the ILC	luminosity, focusing, quadrupole, positron	724
	G. Burt, A.C. Dexter Cockcroft Institute, Warrington, Cheshire C.D. Beard, P. Goudket CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire L. Bellantoni Fermilab, Batavia, Illinois
	In order to achieve acceptable luminosity for ILC crossing angles greater than a few mrad, RF deflection cavities must be used to rotate electron and position bunches leading up to the IP. A bunch that passes through a deflection cavity at a phase where the deflection averages to zero receives a crab kick leading to a finite rotation at the IP. For a beam energy of 500GeV and a crossing angle of 20mrad, the required crab kick is about 19.5MV at 1.3GHz and 6.5MV at 3.9GHz. Cavities are needed on both beams and are likely to be positioned about 12m before the IP. Any RF phase error between the bunch and the cavity leads to a deflection of the bunch in addition to a rotation of the bunch. Any differential phase error between the cavities leads to differing deflections and consequential loss in luminosity. Collaborative work with FNAL, being undertaken to develop a variant of their 3.9GHz CKM cavity optimised for an ILC solution, is described. Current analysis favours a solution with four nine-cell cavities on each beam. It is anticipated that the cavities will be run CW and driven from small Klystron/s (< 5kW) or solid state amplifiers.* *We would like to thank Chris Adolphsen, SLAC, for his help in technical discussions, which were greatly appreciated.

MOPLS076	The Stimulated Breit-Wheeler Process as a Source of Background e⁺e^- Pairs at the ILC	photon, background, resonance, electromagnetic-fields	727
	A.F. Hartin, A.F. Hartin OXFORDphysics, Oxford, Oxon
	Passage of beamstrahlung photons through the bunch fields at the interaction point of the ILC determines background pair production. The number of background pairs per bunch crossing due to the Breit-Wheeler, Bethe-Heitler and Landau-Lifshitz processes is well known. However the Breit-Wheeler process also takes place in and is modified by the bunch fields. A full QED calculation of this Stimulated Breit-Wheeler process reveals cross section resonances due to the virtual particle reaching the mass shell. The one loop Electron Self energy in the bunch field is also calculated and included as a radiative correction. The bunch field is considered to be a contant crossed electromagnetic field with associated bunch field photons. Resonance is found to occur whenever the energy of contributed bunch field photons is equal to the beamstrahlung photon energy. The Stimulated Breit-Wheeler cross section exceeds the ordinary Breit-Wheeler cross section by several orders of magnitude and a significantly different pair background may result.

MOPLS079	The Charged Beam Dumps for the International Linear Collider	linear-collider, collider, photon, TESLA	736
	R. Appleby UMAN, Manchester J.R.J. Bennett, T.A. Broome CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon C. Densham CCLRC/DL, Daresbury, Warrington, Cheshire H. Vincke CERN, Geneva
	The baseline configuration of the International Linear Collider requires 2 beam dumps per interaction region, each rated to 18MW of beam power, together with additional beam dumps for tuning purposes and machine protection. The baseline design uses high pressure moving water dumps, first developed for the SLC and used in the TESLA design, although a gas based dump is also being considered. In this paper we discuss the progress made by the international community on both physics and engineering studies for the beam dumps.

MOPLS080	A Laser-wire System at the ATF Extraction Line	laser, photon, extraction, optics	738
	S.T. Boogert, G.A. Blair, G.E. Boorman, A. Bosco, L. Deacon, C. Driouichi Royal Holloway, University of London, Surrey A. Aryshev, H. Hayano, V. Karataev, K. Kubo, N. Terunuma, J. Urakawa KEK, Ibaraki A. Brachmann, J.C. Frisch, M.C. Ross SLAC, Menlo Park, California N. Delerue JAI, Oxford S. Dixit, F.B. Foster, G.F. Gannaway, D.F. Howell, Q.M. Qureshi, A. Reichold, R. Senanayake OXFORDphysics, Oxford, Oxon L.J. Jenner Cockcroft Institute, Warrington, Cheshire T. Kamps BESSY GmbH, Berlin
	A new laser-wire system has been installed at the ATF extraction line at KEK, Tsukuba. The system aims at a micron-scale laser spot size and employs a mode-locked laser system. The purpose-built interaction chamber, light delivery optics, and lens systems are described, and the first results are presented.

MOPLS087	Series Test of High-gradient Single-cell Superconducting Cavity for the Establishment of KEK Recipe	KEK, vacuum, pick-up, superconductivity	756
	T. Saeki, F. Furuta, Y. Higashi, T. Higo, S. Kazakov, H. Matsumoto, Y. Morozumi, K. Saito, N. Toge, K. Ueno, H. Yamaoka KEK, Ibaraki M.Q. Ge IHEP Beijing, Beijing K. Kim Kyungpook National University, Daegu R.S. Orr University of Toronto, Toronto, Ontario
	We have performed a series of vertical tests of single cell Niobium superconducting cavities at 2 degrees Kelvin. These tests aimed at establishing the feasibility of reaching an accelerating gradient of 45 MV/m on a routine basis. The cavity profiles were all of the KEK low loss design and were fabricated from deep drawn Niobium half shells using electron beam welding. The cavity surface preparation followed an established KEK procedure of centrifugal barrel polishing, light chemical polishing, high temperature annealing, electropolishing, and finally a high pressure water rinse. Of the six cavities tested, three exceeded 45 MV/m on the first test. This clearly establishes the feasibility of this gradient. In this paper we describe these tests and our future program for optimising the surface preparation.

MOPLS088	Resonant Kicker System for Head-on-collision Option of Linear Collider	kicker, positron, linear-collider, collider	759
	Y. Iwashita Kyoto ICR, Uji, Kyoto
	The separation of incoming and outgoing (electron and positron) beams at the interaction point of a linear collider is investigated using a resonant kicker system. It should enable head-on-collisions at the interaction point with the use of staggered passing times for each bunch at certain locations. Magnetic core materials for such a resonant kicker with a frequency of 6MHz are under investigation. Such a kicker system should minimize the perturbation of the incoming bunch with a finite bunch length, while it kicks the outgoing bunch by more than 1 millirad. Various arrangements of such kickers along the beamlines are discussed.

MOPLS103	A High-gradient Test of a 30 GHz Molybdenum-iris Structure	CLIC, CTF3, vacuum, diagnostics	801
	W. Wuensch, C. Achard, H.-H. Braun, G. Carron, R. Corsini, S. Doebert, R. Fandos, A. Grudiev, E. Jensen, T. Ramsvik, J.A. Rodriguez, J.P.H. Sladen, I. Syratchev, M. Taborelli, F. Tecker, P. Urschütz, I. Wilson CERN, Geneva H. Aksakal Ankara University, Faculty of Sciences, Tandogan/Ankara Ö.M. Mete Ankara University, Faculty of Engineering, Tandogan, Ankara
	The CLIC study is investigating a number of different materials as part of an effort to find ways to increase achievable accelerating gradient. So far, a series of rf tests have been made with a set of identical-geometry structures: a tungsten-iris 30 GHz structure, a molybdenum-iris 30 GHz structure and a scaled molybdenum-iris X-band structure. A second molybdenum-iris 30 GHz structure of the same geometry has now been tested in CTF3 with pulse lengths up to 350 ns. The new results are presented and compared to those of the previous structures to determine dependencies of quantities such as accelerating gradient, material, frequency, pulse length, power flow, conditioning rate and breakdown rate.

MOPLS105	Collimators for ILC	undulator, positron, target, radiation	807
	A.A. Mikhailichenko Cornell University, Department of Physics, Ithaca, New York
	We considered two types of collimators for usage in undulator conversion system of ILC. In the first, the Pyrolytic graphite is used and it is installed in front of a target; the second one uses InGa alloy in rotating cylinder. The last one installed in front of undulator. Collimators allow absorption single train on bunches in ILC and enhace the photon polarization.

MOPLS106	Independent Operation of Electron/Positron Wings of ILC	positron, kicker, target, linac	810
	A.A. Mikhailichenko Cornell University, Department of Physics, Ithaca, New York
	We represent a concept of fast feedback system allowing independent operation of electron-positron wings of ILC.

MOPLS107	Test of SC Undulator for ILC	undulator, positron, vacuum, collider	813
	A.A. Mikhailichenko Cornell University, Department of Physics, Ithaca, New York
	We represent details of design and results of test SC 40cm-long undulator having period 10mm and aperture ~8 mm allowing K=0.7. This undulator can be used in ILC positron conversion system.

MOPLS108	Liquid Metal Target for ILC	target, positron, undulator, single-bunch	816
	A.A. Mikhailichenko Cornell University, Department of Physics, Ithaca, New York
	We considered the Hg target for gamma/positron conversion suitable for usage in ILC project. Positron scheme generation with undulator allows usage thin Hg jet confined in profiled duct with rectangular cross-section.

MOPLS109	Operational Experience with Undulator for E-166	undulator, positron, vacuum, SLAC	819
	A.A. Mikhailichenko Cornell University, Department of Physics, Ithaca, New York
	We represent results of operation of 2.54 mm period, K=0.2, up to 30 Hz undulator used in E-166 experiment for polarized positron production. One peculiarity is in usage of Ferrofluid for cooling.

MOPLS113	Commissioning of the ALTO 50 MeV Electron Linac	linac, target, ion, quadrupole	825
	J. Lesrel, J. Arianer, M. Arianer, O. Bajeat, J-M. Buhour, H. Bzyl, F. Carrey, M. Chabot, J.-L. Coacolo, T. Corbin, H. Croizet, J.-M. Curaudeau, F. Doizon, M. Ducourtieux, J.-M. Dufour, S. Essabaa, D. Grialou, C. Joly, M. Kaminski, H. Lefort, B. Lesellier, G. Magneney, L. Mottet, Y. Ollivier, C. Planat, M. Raynaud, Y. Richard, A. Said, A. Semsoum, F. Taquin, C. Vogel IPN, Orsay G. Bienvenu, J-N. Cayla, M. Desmons LAL, Orsay
	The ALTO 50 MeV electron linac is dedicated to the production of neutron-rich radioactive nuclei using the photo-fission process and the optimisation of the target-ion source system for SPIRAL 2 and Eurisol projects. A description of the accelerator consisting in 3 Mev injector (old test station of LAL), LIL accelerating structure, RF power plant, beam line, control system and diagnostics will be given. Specified and measured beam parameters will be compared to show the performance for the photo-fission and eventually other applications.

MOPLS121	The DAFNE Beam Test Facility: from 1 to 10 Milliards of Particles	photon, linac, positron, target	846
	G. Mazzitelli, B. Buonomo, L. Quintieri INFN/LNF, Frascati (Roma) P. Valente INFN-Roma, Roma
	The DAFNE Beam Test Facility is operating since 2002, providing electrons, positrons and photons from the single particle up to 1010 particleS per spill and from 20 to 750 MeV. During these years, the facility has hosted tens of high energy test and experiments coming from all Europe, operating in a wide spread of multiplicity and energy. Operation performance and parameters, tools and diagnostics, as well as the main results obtained, are presented.

MOPLS124	The KEK Injector Upgrade for the Fast Beam-Mode Switch	KEKB, linac, positron, injection	855
	M. Satoh KEK, Ibaraki
	The KEK linac is a 600-m-long linear accelerator with maximum energy 8-GeV electron and 3.5-GeV positron, and it is used as an injector for 4-rings (KEKB e-/ e+, PF, PF-AR). To increase the operation efficiency, we have an injector upgrade plan for the quasi-simultaneous injection. In this paper, we will present the operation scheme and the construction of a new beam transport line in detail.

MOPLS133	Preliminary Studies of Ion Effects in ILC Damping Rings	ion, damping, TESLA, ion-effects	867
	G.X. Xia, Eckhard. Elsen DESY, Hamburg
	Ion effects are potentially detrimental to the performance of the damping rings for the International Linear Collider (ILC). In this paper, the ion effects in the damping rings of ILC are briefly reviewed. Fast beam-ion instability (FBII) is studied in the linear regime. The growth rates and the beam blowups due to FBII are analytically calculated and compared for two variants of the ILC damping ring designs (OCS and TESLA) and discussed as a function of the vacuum pressure. Finally, some detailed simulation results are also presented.

MOPLS141	The Proposed Conversion of CESR to an ILC Damping Ring Test Facility	emittance, damping, wiggler, positron	891
	M.A. Palmer, R.W. Helms, D. L. Rubin, D. Sagan, J.T. Urban Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York M. Ehrlichman University of Minnesota, Minneapolis, Minnesota
	In 2008 the Cornell Electron Storage Ring (CESR) will end nearly three decades of providing electron-positron collisions for the CLEO experiment. At that time it will be possible to reconfigure CESR as a damping ring test facility, CesrTF, for the International Linear Collider (ILC) project. With its complement of 12 damping wigglers, CesrTF will offer horizontal emittances in the few nanometer range and, ideally, vertical emittances approaching those specified for the ILC damping rings. An important feature of the CesrTF concept is the ability to operate with positrons or electrons. Positron operation will allow detailed testing of electron cloud issues critical for the operation of the ILC positron damping rings. Other key features include operation with wigglers that meet or exceed all ILC damping ring requirements, the ability to operate from 1.5 to 5.5 GeV beam energies, and the provision of a large insertion region for testing damping ring hardware. We discuss in detail the CesrTF machine parameters, critical conversion issues, and experimental reach for damping ring studies.

MOPLS143	Suppression of Secondary Emission in a Magnetic Field using Sawtooth Surface	dipole, damping, impedance, quadrupole	897
	L. Wang, T.O. Raubenheimer, G.V. Stupakov SLAC, Menlo Park, California
	The effect of surface roughness on the secondary electron emission from a sawtooth surface in a magnetic field under electron bombardment is investigated using a Monte-Carlo method. Some of the secondary electrons emitted from the sawtooth surface return to the surface within their first few gyrations, resulting in low effective secondary electron yield. A sawtooth surface in magnetic field can significantly reduce the secondary emission yield below the multipacting threshold.

TUXPA02	RHIC Operational Status and Upgrade Plans	RHIC, ion, luminosity, proton	905
	W. Fischer BNL, Upton, Long Island, New York
	Since 2000 RHIC has collided, at 8 energies, 4 combinations of ion species, ranging from gold ions to polarized protons, and including the collisions of deuterons with gold ions. During that time the heavy ion luminosity increased by 2 orders of magnitude, and the proton polarization in store reached 46% on average. Planned upgrades include the evolution to the Enhanced Design parameters by 2008, the construction of an Electron Beam Ion Source (EBIS) by 2009, the installation of electron cooling for RHIC II, and the implementation of the electron-ion collider eRHIC. We review the expected operational performance with these upgrades.
	Transparencies

TUYPA01	Femtosecond Bunch Length Measurements	radiation, diagnostics, laser, CDR	915
	S.P. Jamison CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire G. Berden FOM Rijnhuizen, Nieuwegein W.A. Gillespie, P.J. Phillips University of Dundee, Nethergate, Dundee, Scotland A. MacLeod UAD, Dundee B. Steffen DESY, Hamburg
	The measurement of ultrashort longitudinal bunch profiles is of growing importance to accelerator development and operation. With requirements of ~10fs time resolution, and a desire for non-destructive and real time diagnostics, the challenges for diagnostic development are significant. Alongside more established transverse deflecting cavity and CTR measurement techniques, new approaches arriving from the field of ultrafast lasers offer significant potential; Ultrafast electro-optic detection has now been demonstrated on several accelerators, and in many distinct forms, although challenges remain in getting to the desired time resolution. Proposed schemes combining ultrafast laser diagnostics with FEL interactions, such as the "optical replica" scheme also have considerable potential. Here, an overview of the current status of femtosecond scale longitudinal profile diagnostics will be given, together with an outlook to the future expectations.
	Transparencies

TUZBPA01	The ERL High Energy Cooler for RHIC	RHIC, ERL, luminosity, emittance	940
	I. Ben-Zvi BNL, Upton, Long Island, New York
	This talk will first briefly review high-energy electron cooling, including the recent results from Fermilab. The main empasis will be on describing the proposed electron-cooling device for RHIC, based on an Energy Recovery Linac. Finally, results from the prototype ERL will presented.
	Transparencies

TUOAFI03	Production of MeV Photons by the Laser Compton Scattering Using a Far Infrared Laser at SPring-8	laser, FIR, photon, storage-ring	961
	H. Ohkuma, M. Shoji, S. Suzuki, K. Tamura, T. Yorita JASRI/SPring-8, Hyogo-ken Y. Arimoto Osaka University, Osaka M. Fujiwara, K. Kawase RCNP, Osaka K. Nakayama, S. Okajima Chubu University, Kasugai, Aichi
	In order to produce MeV gamma-ray by the Laser Compton scattering (LCS), a high power optically pumped Far Infrared (FIR) laser has been developed at SPring-8. In the case of the SPring-8 storage ring, the momentum acceptance is so large (± 200 MeV) that the scattered electron is re-accelerated, then the stored beam is not lost by the LCS process. The beam diagnostics beamline is used to inject a FIR laser beam against 8-GeV stored electron beam and to extract MeV gamma-ray produced by LCS. The FIR laser system, gamma-ray production system, and measured gamma-ray spectrum will be presented. Future plans will also be introduced. In order to produce higher intense gamma-ray, we are constructing new gamma-ray production system at another beamline.
	Transparencies

TUYFI02	Latest Developments on Insertion Devices	undulator, wiggler, permanent-magnet, ESRF	969
	P. Elleaume, J. Chavanne ESRF, Grenoble
	A review will be carried out of the developments on Insertion Devices that have taken place world wide in the last few years. These include the development of long period electro-magnet undulators, the operational results of a number of Apple-II undulators, the development of superconducting short period multipole wigglers, as well as the construction and operation of several in-vacuum undulators. The construction of a large number of competitive middle energy synchrotron sources in the hard X-ray range means that the need to increase the photon energy in the fundamental peak of an undulator is becoming a very important issue. Two main development strategies are currently being investigated. One consists of using superconducting undulator technology, the other of a further refinement of the in-vacuum undulator permanent magnet technology with cryogenic cooling of the magnetic assembly. The issues and challenges that are part of each approach will be presented, together with the latest results.
	Transparencies

TUOCFI02	First Results of SNS Laser Stripping Experiment	laser, ion, proton, SNS	980
	V.V. Danilov, A.V. Aleksandrov, S. Assadi, J. Barhen, Y. Braiman, D.L. Brown, W. Grice, S. Henderson, J.A. Holmes, Y. Liu, A.P. Shishlo ORNL, Oak Ridge, Tennessee
	Thin carbon foils are used as strippers for charge exchange injection into high intensity proton rings. However, the stripping foils become radioactive and produce uncontrolled beam loss, which is one of the main factors limiting beam power in high intensity proton rings. Recently, we presented a scheme for laser stripping of an H^- beam for the SNS ring. First, H^- atoms are converted to H0 by a magnetic field, then H0 atoms are excited from the ground state to the upper levels by a laser, and the excited states are converted to protons by a magnetic field. This paper presents first results of the SNS laser stripping proof-of-principle experiment. The experimental setup is described, and possible explanations of the data are discussed.
	Transparencies

TUODFI02	DAFNE Experience with Negative Momentum Compaction	positron, luminosity, lattice, feedback	989
	M. Zobov, D. Alesini, M.E. Biagini, A. Drago, A. Gallo, C. Milardi, P. Raimondi, B. Spataro, A. Stella INFN/LNF, Frascati (Roma)
	There are several potential advantages for a collider operation with a lattice having a negative momentum compaction factor (alfa): bunches can be shorter and have a more regular shape; longitudinal beam-beam effects and synchrobetatron resonances are predicted to be less dangerous; requirements on sextupole strengths can be relaxed because there is no head-tail instability with the negative chromaticity. Since the lattice of the Frascati e⁺e^- Phi-factory DAFNE is flexible enough to provide collider operation with alfa < 0, we have exploited this possibility to study experimentally the beam dynamics. The negative momentum compaction lattices have been successfully implemented and stable 1 A currents have been stored in both the electron and positron rings without any problem for RF cavities and feedback systems operation. First collisions have been tested at low currents. In this paper we describe the experimental results and compare them with expectations and numerical simulations. Present limitations to DAFNE operation with alfa < 0 are also discussed.
	Transparencies

TUODFI03	Operational Status of CESR-c	luminosity, optics, wiggler, positron	992
	J.A. Crittenden Cornell University, Department of Physics, Ithaca, New York
	We summarize recent running experience at the Cornell Electron Storage Ring operating as a high-statistics production-threshold factory for mesons containing charm quarks. Since beginning operation at beam energies near 2 GeV in late 2003, CESR has accumulated world-record samples of D and D$_s$ meson decays and has also operated in an energy-scanning mode, making unique contributions to the presently very active field of charm spectroscopy. CESR lattice design is characterized by the versatility provided by the variety of beam-line components applied to the challenges imposed by the beam-beam interactions at the parasitic crossing points in the pretzel orbits and the necessity of powerful superconducting wiggler magnets used to tune damping and emittance. We describe the observed tune-plane, beam-current and luminosity limits, as well as our understanding of their sources and near-term plans for operational improvements.
	Transparencies

TUPCH004	Commissioning of the LNLS X-ray BPMs	diagnostics, dipole, feedback, synchrotron	998
	S.R. Marques, P.F. Tavares LNLS, Campinas
	We present experimental results of the commissioning of staggered-pair blade X-Ray beam position monitor (XBPM) recently developed and installed at the diagnostic beamline of the UVX electron storage ring at the Brazilian Synchrotron Light Laboratory (LNLS). The results obtained with a prototype XBPM indicate that the short-term and long-term data are both in agreement with the data from a commercially acquired XBPM installed at the same beamline, as well as with the data of the electron storage ring RF BPMs. In this paper we present the commissioning results of the LNLS XBPM.

TUPCH006	A Wideband Intercepting Probe for the TRIUMF Cyclotron	cyclotron, simulation, impedance, linac	1001
	V.A. Verzilov, D. Cameron, D.T. Gray, S. Kellogg, M. Minato, W.R. Rawnsley TRIUMF, Vancouver
	An intercepting probe for the TRIUMF cyclotron capable of measuring the phase and time structure of the circulating beam was designed, manufactured, installed into the tank and tested. A model of the probe head in the form of a 50 Ohm parallel plate transmission line was developed and simulated to operate up to 2 GHz. Thermal simulations show that the probe can withstand at least 500 nA of average current for the 500 MeV beam. In laboratory tests the probe demonstrated a bandwidth in excess of 1 GHz. The probe was mounted on a 3 m long drive and is capable of travelling over 0.5 m at an angle of 27 degree w.r.t. the cyclotron radius. The signals extracted from the probe are processed by a pair of diplexers, where low frequency and high frequency components are separated. The low frequency signal is directed to our standard electronics for processing and provides both dc current and a time of flight signal with a rise time of about 100 ns. At the high frequency output a signal-to-noise ratio of about 4 at 250 nA average current and 0.1 % duty cycle was measured in the presence of rf background from the cyclotron resonators. A bunch time structure as short as 1 ns was resolved.

TUPCH008	Behavior of the BPM System During the First Weeks of SOLEIL Commissioning	SOLEIL, storage-ring, instrumentation, synchrotron	1007
	J.-C. Denard, L. Cassinari, N. Hubert, N.L. Leclercq, D. Pedeau SOLEIL, Gif-sur-Yvette
	SOLEIL, a new synchrotron light source built near Paris in France, is pioneering a new high resolution electron Beam Position Monitor (BPM) system to achieve stability of the beams at the micron level, as required for the beamlines. The same BPM system allows also measurement of the beam position in turn-by-turn mode for various machine physics studies. The system combines the high stability characteristic of multiplexed input channels and the flexibility of a digital system. Instrumentation Technologies developed the Libera module upon SOLEIL proposals and requirements. The performances of the system evaluated after the Booster and the storage ring commissioning will be presented.

TUPCH019	Laser-based Beam Diagnostic for the Front End Test Stand (FETS) at RAL	laser, ion, emittance, dipole	1037
	C. Gabor IAP, Frankfurt-am-Main D.A. Lee Imperial College of Science and Technology, Department of Physics, London A.P. Letchford CCLRC/RAL/ISIS, Chilton, Didcot, Oxon J.K. Pozimski CCLRC/RAL, Chilton, Didcot, Oxon
	High power proton accelerators (HPPA) are required for several future projects like spallation sources or a neutrino factory. Compared with existing machines the beam power therefore has to be increased by a factor of 30. The Front end test stand at RAL is being built to demonstrate that a chopped Hminus beam of 60 mA at 3 MeV with 50 pps and sufficiently high beam quality, as required for all proposed Proton drivers, can be built. For the test stand a comprehensive set of beam diagnostics is also required. Due to the high beam energy and power non destructive diagnostic methods are favorable. Hminus beams offer the possibility to use intense laser light to detach the additional electron and use the produced particles for beam diagnostics. The principle is appropriate to determine the transversal beam density distribution as well as the transversal and longitudinal beam emittance in front and behind the RFQ. A detailed layout of the beam diagnostics including a discussion of the predicted spatial and temporal resolution and the dynamic range of the proposed devices will be presented.

TUPCH021	Principles of longitudinal beam diagnostics with coherent radiation	radiation, DESY, diagnostics, laser	1040
	O. Grimm DESY, Hamburg
	The Kramers-Kronig dispersion relation connects the real and imaginary part of a response function under very general assumptions. It is used in the context of accelerator physics for longitudinal bunch diagnostics as a phase retrieval technique: the modulus of the complex form factor (the Fourier transform of the charge distribution) is accessible experimentally, and the missing phase then (partially) reconstructed to allow an inversion of the Fourier transform. Contrary to real and imaginary part, the connection between modulus and phase is not unique anymore due to the possibility of zeros of the form factor in the complex frequency plane that cannot be measured. This paper gives a mathematically explicit, step-by-step derivation of the phase reconstruction technique for bunch diagnostics, and it explains the problem of zeros and their practical effect with some examples. The intention is not utmost mathematical rigour, but a clear, accessible explanation of all steps involved.

TUPCH022	Large Horizontal Aperture BPM for use in Dispersive Sections of Magnetic Chicanes	pick-up, simulation, laser, SMA	1043
	K.E. Hacker, H. Schlarb DESY, Hamburg F. Loehl Uni HH, Hamburg
	A beam position monitor with a large horizontal aperture for use in dispersive sections of FLASH magnetic chicanes will be installed in October 2006. It has a horizontal range of 13 cm and a resolution requirement of better than 10 microns. A stripline design mounted perpendicularly to the the electron beam direction is used to provide broadband electrical pulses traveling in opposite directions, the phases of which give a measure of the beam position. The phase measurement will be accomplished through an optical method developed for a beam arrival time monitor. Results from simulation and recent beam arrival-time measurements will be used to justify expectations for the BPM performance.

TUPCH023	Direct Observation of Beam-beam Induced Dynamical Beta Beating at HERA	luminosity, proton, synchrotron, synchrotron-radiation	1046
	G. Kube, F.J. Willeke DESY, Hamburg
	The Hadron Electron Ring Anlage (HERA) at DESY provides collisions between a 920 GeV proton beam and a 27.5 GeV electron beam in two interaction regions. The strong beam-beam force, which mainly affects the electrons, induces a tune shift together with a dynamical beta beat. The latter leads to a modification of the transverse beam profile, which can be observed in different profile monitors in HERA. The time-like evolution of the electron beam shape during luminosity tuning and before and after dump of the proton beam, averaged over all bunches, could be studied by means of a synchrotron radiation profile monitor. Measurements with a wire scanner allowed to see the beam-beam force's influence on each individual bunch at the expense of resolution. The observations could be explained qualitatively in the frame of linear incoherent beam-beam interaction.

TUPCH024	Comparative Study of Bunch Length and Arrival Time Measurements at FLASH	laser, SASE, FEL, DESY	1049
	H. Schlarb, A. Azima, S. Düsterer, M. Huening, E.-A. Knabbe, M. Roehrs, R. Rybnikov, B. Schmidt, B. Steffen DESY, Hamburg M.C. Ross SLAC, Menlo Park, California P. Schmüser, A. Winter Uni HH, Hamburg
	Diagnostic devices to precisely measure the longitudinal electron beam profile and the bunch arrival time require elaborate new instrumentation techniques. At the VUV-FEL, two entirely different methods are used. The bunch profile can be determined with high precision by a transverse deflecting RF structure. The method is disruptive and does not allow to monitor multiple bunches in a macro-pulse train. Therefore, it is augmented by two non-disruptive electro-optical devices, called EO and TEO. The EO setup uses a dedicated diagnostic laser synchronized to the machine RF. The longitudinal electron beam profile is encoded in the intensity profile of a chirped laser pulse and analyzed by looking at the spectral composition of the pulse. The second setup, TEO, utilizes the TiSa-based laser system used for pump-probe experiments. Here, the temporal electron shape is encoded into a spatial dimension of laser pulse by an intersection angle between the laser and the electron beam at the EO-crystal. In this paper, we present a comparative study of bunch length and arrival time measurements performed simultaneously with all three experimental techniques.

TUPCH025	Precision RF Gun Phase Monitor System for the VUV-FEL	laser, gun, acceleration, power-supply	1052
	H. Schlarb, N. Heidbrook, H. Kapitza, F. Ludwig, N. Nagad DESY, Hamburg
	For RF photo-injectors, the properties of the high brightness beam critically depend on the synchronization between the RF gun acceleration phase and the photo-cathode laser. At the VUV-FEL, the phase stability is determined by operating the RF gun close to zero-crossing RF phase. This allows the conversion of phase variations into charge variations which then is readout by a precision charge measurement system based on toroids. In this paper, we discuss the limitation of this method. Resolution reduction of the charge measurement system due to electro-magnetic-interference is discussed in detail.

TUPCH026	Single Shot Longitudinal Bunch Profile Measurements at FLASH using Electro-optic Techniques	laser, linac, SASE, FEL	1055
	B. Steffen, E.-A. Knabbe, B. Schmidt DESY, Hamburg G. Berden, A.F.G. van der Meer FOM Rijnhuizen, Nieuwegein W.A. Gillespie, P.J. Phillips University of Dundee, Nethergate, Dundee, Scotland S.P. Jamison, A. MacLeod UAD, Dundee P. Schmüser Uni HH, Hamburg
	For the high-gain operation of a SASE FEL, extremly short electron bunches are essential to generate sufficiently high peak currents. At the superconducting linac of the VUV-FEL at DESY, we have installed an electro-optic experiment with temporal decoding and spectral decoding to probe the time structure of the electric field of single sub 200fs e-bunches. In this technique, the field-induced birefringence in an electro-optic crystal is encoded on a chirped ps laser pulse. The longitudinal electric field profile of the electron bunch is then obtained from the encoded optical pulse by a single-shot cross correlation with a 30 fs laser pulse using a second-harmonic crystal (temporal decoding) or by a single-shot measurement of its spectrum (spectral decoding). In the temporal decoding measurements an electro-optic signal of 230fs FWHM was observed, and is limited by the material properties of the particular electro-optic crystal used. Bunch profile and time jitter measurements were obtained simultaneously with VUV SASE operation.

TUPCH027	Time Resolved Single-shot Measurements of Transition Radiation at the THz Beamline of FLASH using Electro-optic Spectral Decoding	radiation, laser, FEL, DESY	1058
	B. Steffen, E.-A. Knabbe, B. Schmidt DESY, Hamburg G. Berden, A.F.G. van der Meer FOM Rijnhuizen, Nieuwegein W.A. Gillespie, P.J. Phillips University of Dundee, Nethergate, Dundee, Scotland S.P. Jamison, A. MacLeod UAD, Dundee P. Schmüser Uni HH, Hamburg
	Single-shot electro-optic detection was used to measure the temporal profile of coherent transition radiation (CTR) pulses at the VUV-FEL at DESY. The CTR was generated from single bunches kicked to an off-axis screen, with the radiation transported through a 20m long transfer line imaging the CTR from a radiation screen to an experimental station outside the accelerator tunnel. Bipolar pulses with a FWHM less than 1ps have been measured and are consistent with simulations of the propagation of radiation through the transfer line.

TUPCH028	Layout of the Optical Synchronization System for FLASH	laser, diagnostics, feedback, DESY	1061
	A. Winter, P. Schmüser, A. Winter Uni HH, Hamburg F. Loehl, F. Ludwig, H. Schlarb, B. Schmidt DESY, Hamburg
	The present RF synchronization system of the VUV-FEL can typically stabilize the arrival time of the electron bunches at the undulator to about 200 fs on a timescale of minutes and to several picoseconds on a timescale of hours. To improve the machine stability and to ensure optimal performance for the VUV-FEL user facility, a new ultra-precise timing system is mandatory. The optical synchronization system under construction will satisfy three goals: Firstly, it provides a local oscillator frequency with the same stability as the existing low-level RF regulation, secondly, it can synchronize the experimental lasers of the FEL users with a precision in the order of 30 fs, thirdly, it provides an ultra-stable reference for beam arrival time measurements and enables a feedback on the electron beam to compensate residual drifts and timing jitter. The optical synchronization system is based on an optical pulse train from a mode-locked laser with a highly stabilized repetition rate. This paper describes the proposed layout of the optical synchronization system, the integration into the machine layout and the diagnostic experiments to monitor the performance of the system.

TUPCH030	A Beam Diagnostics System for the Heidelberg Cryogenic Storage Ring CSR	CSR, ion, diagnostics, pick-up	1067
	T. Sieber, H. Fadil, M. Grieser, A. Wolf, R. von Hahn MPI-K, Heidelberg
	The storage of rotationally non-excited molecules and highly charged ions requires lowest temperatures and vacuum pressures. At the MPI-K Heidelberg a cryogenic storage ring (CSR) for atomic and molecular physics experiments is under development. The CSR shall allow operation at temperatures of 2 K and pressures down to 1·10^-15 mbar. The ring consists of electrostatic elements and has a circumference of ~35 m. It is housed inside a large cryostat, cooled by a (20W @ 2K) Helium refrigerator. To reach low UHV pressures already at room temperature the whole machine has to be bakeable up to 300°C. These boundary conditions, together with the low charge states, low velocities and low intensities (1nA-1muA) of the ions, put strong demands on the beam diagnostics system. Some beam parameters like profile, position and intensity cannot be measured with “standard” beam diagnostics technology. Here new or further developments are required. The paper gives a general view of the beam diagnostics concept for the CSR and shows in more detail possible solutions for measurement of beam position and beam profile.

TUPCH031	A New SQUID-based Measurement Tool for Characterization of Superconducting RF Cavities	cryogenics, pick-up, shielding, TESLA	1070
	K. Knaack, K. Wittenburg DESY, Hamburg R. Neubert, S. Nietzsche, W. Vodel FSU Jena, Jena A. Peters GSI, Darmstadt
	In this contribution a LTS-SQUID based measurement tool for characterization of superconducting RF cavities for the upcoming X-FEL project at DESY will be presented. The device makes use of the Cryogenic Current Comparator (CCC) principle and measures the so-called dark current, generated e.g. by superconducting cavities at high voltage gradients. To achieve the maximum possible energy the gradients should be pushed near to the physical limit of 50 MV/m. The measurement of the undesired field emission of electrons (the so-called dark current) in correlation with the gradient will give a proper value to characterize the performance of the RF cavities. The CCC mainly consists of a high performance LTS-DC SQUID system which is able to measure extremely low magnetic fields, e.g. caused by the extracted dark current of the RF cavities. Therefore, a special designed toroidal niobium pick-up coil for the passing electron beam is superconducting connected across the input coil of the SQUID. The noise limited sensitivity of the CCC as well as new experimental results with the whole measurement device assembled in a special wide-necked LHe cryostat will be presented.

TUPCH032	Precise Measurements of the Vertical Beam Size in the ANKA Storage Ring with an In-air X-ray Detector	resonance, synchrotron, radiation, photon	1073
	A.-S. Müller, I. Birkel, E. Huttel, P. Wesolowski FZK, Karlsruhe K.B. Scheidt ESRF, Grenoble
	A major part of the X-rays generated in the ANKA dipole magnets is unused by the experimental beamlines and is, on a number of dipoles, absorbed in a conical shaped Copper absorber. The 8 mm thickness that it presents lets a tiny fraction of the hard X-rays above 70KeV enter the free air space behind it. The transmitted power of only a few uW/mrad hor. is sufficient to be detected, with sub-second measurement time, by a novel In-Air X-ray detector. This extremely compact and low-cost device is situated just behind the absorber. The design, developed and in use at the ESRF, is based on a Cadmium Tungstenate (CdWO4) scintillator converting X-rays into visible light that is collected and focused onto a commercial CCD camera. Since the small vertical divergence of the high energy photons and the distance of the detector from the source point are known, it is possible to derive the vertical electron beam size with a high intrinsic precision. This paper presents results of beam size measurements as a function of various ANKA machine parameters, that illustrates the great diagnostic potential of this type of detector for a 2.5GeV medium energy light source like ANKA.

TUPCH038	Beam Loss Monitoring and Machine Protection Designs for the Daresbury Laboratory Energy Recovery Linac Prototype	radiation, beam-losses, ERLP, monitoring	1088
	S.R. Buckley, R.J. Smith CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
	Daresbury Laboratory is currently constructing an energy recovery linac prototype (ERLP). This is to carry out the necessary research and development of the technology of photo-cathode electron guns and superconducting linacs so that a fourth generation light source (4GLS) can be designed and constructed. Beam loss monitoring and machine protection systems are vital areas for the successful operation of the ERLP. These systems are required, both for efficient commissioning and for hardware protection during operation. This paper gives an overview of the system requirements, options available and details of the final design specification.

TUPCH041	Electro-optic Diagnostics on the Daresbury Energy Recovery Linac	laser, CSR, free-electron-laser, diagnostics	1094
	P.J. Phillips, W.A. Gillespie University of Dundee, Nethergate, Dundee, Scotland S.P. Jamison CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire A. MacLeod UAD, Dundee
	An electro-optic longitudinal bunch profile monitor is being implemented on the 4GLS prototype energy recovery linac (ERL/p) at Daresbury Laboratories and will be used both to characterise the electron bunch and to provide a testbed for electro-optic techniques. The electro-optic station is located immediately after the bunch compressor, and within the FEL cavity; its location allows it to draw on nearby beam profile monitors and CTR and CSR diagnostics for calibration and benchmarking. We discuss the implementation and planned studies on electro-optic diagnostics with this diagnostic station.

TUPCH042	The Optical System for a Smith-Purcell Experiment at 45MeV	radiation, background, vacuum, cryogenics	1097
	V. Blackmore, W.W.M. Allison, G. Doucas, C. Perry OXFORDphysics, Oxford, Oxon P.G. Huggard CCLRC/RAL, Chilton, Didcot, Oxon M.B. Johnston University of Oxford, Clarendon Laboratory, Oxford B. Redlich, A.F.G. van der Meer FOM Rijnhuizen, Nieuwegein
	Smith-Purcell (SP) radiation has been used to investigate the longitudinal profile of a 45MeV, picosecond long bunched beam at the FELIX facility, FOM Institute. The three important optical elements that made this experiment possible were (i) high quality optical filters, (ii) nonimaging light concentrators, (iii) and a system to rapidly change between gratings.

TUPCH043	Observations of the Longitudinal Electron Bunch Profile at 45MeV Using coherent Smith-Purcell radiation	radiation, background, linear-collider, collider	1100
	G. Doucas, V. Blackmore, B. Ottewell, C. Perry OXFORDphysics, Oxford, Oxon P.G. Huggard CCLRC/RAL, Chilton, Didcot, Oxon M.B. Johnston University of Oxford, Clarendon Laboratory, Oxford M.F. Kimmitt University of Essex, Physics Centre, Colchester B. Redlich, A.F.G. van der Meer FOM Rijnhuizen, Nieuwegein
	Coherent Smith-Purcell (SP) radiation has been used to determine the longitudinal profile of the electron bunch at the FELIX facility, FOM Institute. Far-infrared radiation was detected using a simple, compact arrangement of 11 pyroelectric detectors. Background radiation was suppressed through the use of high quality optical filters, and an efficient light collection system. The measured bunch profile was most closely in agreement with 90% of the particles contained within 5.5ps, with an approximately triangular temporal profile.

TUPCH047	Diamond Optical Diagnostics: First Streak Camera Measurements	injection, synchrotron, storage-ring, DIAMOND	1112
	C.A. Thomas, G. Rehm Diamond, Oxfordshire
	We present in this paper a first set of measurements of the six-dimensional phase-space of the electron beam in the Diamond storage ring. We recall the predicted performance and compare it with our first measurements. The two pinhole cameras measure the beam size, from which we retrieve the energy spread and the emittance of the beam in both horizontal and vertical directions. We have designed a robust and simple UV-visible beamline, to measure the electron bunch profile and length with a streak camera, and to measure the beam quality using a state-of-the-art single photon counting technique.

TUPCH048	A Study of Emittance Measurement at the ILC	emittance, laser, quadrupole, coupling	1115
	G.A. Blair, I.V. Agapov, J. Carter, L. Deacon Royal Holloway, University of London, Surrey D.A.-K. Angal-Kalinin CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire L.J. Jenner Cockcroft Institute, Warrington, Cheshire M.C. Ross, A. Seryi, M. Woodley SLAC, Menlo Park, California
	The measurement of the ILC emittance in the ILC beam delivery system and the linac is simulated. Estimates of statistical and machine-related errors are discussed and implications for related diagnostics R&D are inferred.

TUPCH049	Proposal for a Fast Scanning System Based on Electro-optics for Use at the ILC Laser-wire	laser, focusing, positron, PETRA	1118
	A. Bosco, G.A. Blair, S.T. Boogert, G.E. Boorman, L. Deacon, C. Driouichi, M.T. Price Royal Holloway, University of London, Surrey
	Electro-optic devices open the possibility of ultra-fast scanning systems for use in intra-train scanning at the ILC, where scanning rates in excess of 100 kHz may be required. A first study of the possibilities is presented together with the first results from a prototype system.

TUPCH050	Beam Profile Measurements with the 2-D Laser-wire	laser, photon, PETRA, injection	1121
	G.A. Blair, I.V. Agapov, S.T. Boogert, G.E. Boorman, A. Bosco, J. Carter, C. Driouichi, M.T. Price Royal Holloway, University of London, Surrey K. Balewski, H.-C. Lewin, F. Poirier, S. Schreiber, K. Wittenburg DESY, Hamburg N. Delerue, D.F. Howell OXFORDphysics, Oxford, Oxon T. Kamps BESSY GmbH, Berlin
	A new laser-wire system has been installed at the PETRA ring at DESY, Hamburg. The system is set up to scan in two dimensions using piezo-driven mirrors and employs a newly acquired injection seeded Q-switched laser. The system is described and first results are presented.

TUPCH053	Bunch Length Characterization Downstream from the Second Bunch Compressor at FLASH DESY, Hamburg	radiation, FEL, CDR, SASE	1127
	E. Chiadroni INFN-Roma II, Roma
	The characterization of the longitudinal density profile of picosecond and sub-picosecond relativistic particle bunches is a fundamental requirement in many particle accelerator facilities, since knowledge of the characteristics of the accelerated beams is of utmost importance for the successful development of the next generation light sources and linear colliders. The development of non-intercepting beam diagnostics is thus necessary to produce and control such beams. First experimental evidences of the non-intercepting nature of diffraction radiation diagnostics are given. The longitudinal bunch distribution downstream of the second bunch compressor of the DESY TTF VUV-FEL has been reconstructed using a frequency-domain technique based on the autocorrelation of coherent diffraction radiation. Due to the low and high frequency suppression, introduced by the experimental apparatus, only a portion of the CDR spectrum participates to the reconstruction of the longitudinal bunch profile. The knowledge of the system frequency response is then crucial in order to correct the results and extrapolate a bunch shape as close as possible to the real one.

TUPCH065	A Prototype of Residual Gas Ionization Profile Monitor for J-PARC RCS	ion, space-charge, IPM, MCP	1163
	K. Satou, N. Hayashi JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken S. Lee, T. Toyama KEK, Ibaraki
	A prototype of a residual gas ionization profile monitor (IPM) for J-PARC RCS has been developed. It consists of electrodes producing electric field to collect ionized ions/electrons, MCP as a signal read-out device, an electron generator to evaluate the gain balance of MCP channels, and a wiggler type magnet producing guiding field. The monitor has been installed in KEK-PS main ring and has been examined using proton beam. At the conference, recent preliminary results of experiments will be reported.

TUPCH067	Time-resolved Beam Emittance Measurement of Dragon-I Linear Induction Accelerator	emittance, radiation, focusing, induction	1166
	G.J. Yang, S. Chen, X. Jiang, Z. Zhang CAEP/IFP, Mainyang, Sichuan
	A beam emittance diagnostic system of an intense pulsed electron beam (20MeV, 2.6kA, 80ns) based on optical transition radiation is developed. A gated CCD camera is used to get time-resolved result. We develop a timing system to avoid the time jitter, an anti-interference system to avoid the electromagnetic interference, and a C++ code to deal with the experimental data. The measured emittance is about 2000�Ð.mm.mrad, which is agree with the result of three gradient method.

TUPCH072	New Generation Streak Camera Design and Investigation	radiation, space-charge, monitoring, simulation	1175
	A.M. Tron LPI, Moscow T.V. Gorlov, I.G. Merinov MEPhI, Moscow
	The only method for electron bunch duration monitoring with a resolution in the order of 10 fs and less is the method of photochronography of the bunch incoherent radiation in the frequency range, for example, of visible light and at realizing streak camera with new principles of its operation. In the paper the streak camera design for measuring both the electron bunches and x-ray pulses duration with the mentioned temporal resolution is presented. The results of the camera investigation, with photoelectron dynamics simulation taking into account space-charge effect and impact of the surface roughness of a spherical photocathode of the 20-50 micrometers radius (forming a modulating gap of spherical configuration) on the camera resolution, are presented and discussed. A. M. Tron and I. G. Merinov. Method of bunch radiation photochronography with 10 femtosecond and less resolution. http://www.physics.ucla.edu/PAHBEB2005/talks/10oct2005/wg2/atron.pdf

TUPCH074	Fast and Precise Beam Energy Monitor Based on the Compton Backscattering at the VEPP-4M Collider	photon, laser, collider, scattering	1181
	N.Yu. Muchnoi, S.A. Nikitin, V.N. Zhilich BINP SB RAS, Novosibirsk
	Accurate knowledge of the colliding beam energies is essential for the current experiments with the KEDR \cite{KEDR} detector at the VEPP-4M collider. Now the experimental activity is focused on the new precise measurement of the tau-lepton mass by studying the behavior of the tau production cross-section near the reaction threshold. To achieve the desired quality of the experiment, an on-line beam energy monitoring by the Compton backscattering of laser light was performed. This approach is found to be a very good supplement to rare energy calibrations by the resonant depolarization technique, saving the beam time for luminosity runs. The method itself does not require electron beam polarization and additionally allows one to measure the electron beam energy spread. The achieved accuracy of the method in the beam energy range 1.7–1.9 GeV is 60 keV.

TUPCH075	Dependence of the Electron Beam Polarization Effect in the Intra-beam Scattering Rate on the Vertical Beam Emittance	polarization, scattering, emittance, coupling	1184
	S.A. Nikitin, I.B. Nikolaev BINP SB RAS, Novosibirsk
	Measurement of the Intra-beam scattering rate is applied in the resonant depolarization technique to detect beam polarization in electron/positron storage rings. A depolarization jump in the counting rate of scattering particles occurs at the instant when the beam becomes unpolarized due to fulfillment of the external spin resonance condition. The magnitude of the jump depends on polarization quadratically. It also depends on some other beam parameters as well as the position of counters relative to the beam orbit. A larger jump implies higher accuracy in absolute calibration of particle energy because the latter is proportional to the spin precession frequency. In contrast to an ordinary one-dimensional approach, we calculate the magnitude of jump subject to, among other things, the vertical component of relative velocity in particle collisions inside the beam. For this purpose, the transverse momentum distribution function is properly modified. Calculations performed for the VEPP-4M storage ring-collider show that the jump may depend significantly on the ratio between the vertical and radial beam emittance. We present results of our recent experiments on study of this dependence.

TUPCH079	Characterisation of the MAX-II Electron Beam: Beam Size Measurements	optics, synchrotron, synchrotron-radiation, radiation	1193
	M. Sjöström, H. Tarawneh, E.J. Wallén MAX-lab, Lund
	Over the last year investigations of the MAX-II electron beam characteristics have been made. Examples of investigated parameters include the beam size, bunch length, vacuum and Touschek lifetimes, and the machine functions. Several upgrades of the MAX II ring have been performed since the commissioning 1995 like a new 100 MHz RF system with a 500 MHz Landau cavity, exchanged injector, and a variety of insertion devices. There is hence a need to systematically characterize the present machine. This systematic characterisation is now underway and this article describes details of the beam size measurements.

TUPCH081	Technical Aspects of the Integration of the Optical Replica Synthesizer for the Diagnostics of Ultra-short Bunches in FLASH at DESY	laser, undulator, DESY, vacuum	1199
	V.G. Ziemann UU/ISV, Uppsala N.X. Javahiraly, P. van der Meulen FYSIKUM, AlbaNova, Stockholm University, Stockholm M. Larsson Stockholm University, Department of Physics, Stockholm E. Saldin, H. Schlarb, E. Schneidmiller, A. Winter, M.V. Yurkov DESY, Hamburg
	In this paper we present an overview of current status of the Optical Replica synthesizer at DESY. The method is based on producing an "optical copy" of the electron bunch with its subsequent analysis with optical techniques. To this end, a near-IR laser beam is superimposed on the electron beam in the first undulator of an optical klystron. In the following dispersive section the laser-induced energy modulation is transformed into a density modulation . The modulated electron bunch then produces a strong optical pulse in the second undulator. Analysis of this near-IR pulse (the optical copy) then provides information about the profile, the slice emittance and the slice energy spread of the electron bunch. We discuss the implementation of such a measurement set-up at the FLASH facility at DESY and investigate the influence of various parameters on the performance of the device. Topics we address include the dispersive chicane, as well as the requirements for the seed laser pulses and the detection and analysis of the near-IR pulse. E. Saldin, et al. "A simple method for the determination of the structure of ultrashort relativistic electron bunches," Nucl. Inst. and Methods A 539 (2005) 499.

TUPCH083	Time-resolved Spectrometry on the CLIC Test Facility 3	radiation, photon, linac, synchrotron	1205
	T. Lefevre, C.B. Bal, H.-H. Braun, E. Bravin, S. Burger, R. Corsini, S. Doebert, C.D. Dutriat, F. Tecker, P. Urschütz, C.P. Welsch CERN, Geneva
	The high charge (>6microC) electron beam produced in the CLIC Test Facility 3 (CTF3) is accelerated in fully loaded cavities. To be able to measure the resulting strong transient effects, the time evolution of the beam energy and its energy spread must be measured with at least 50MHz bandwidth. Three spectrometer lines were installed all along the linac in order to control and tune the beam. The electrons are deflected by a dipole magnet onto an Optical Transition Radiation (OTR) screen, which is observed by a CCD camera. The measured beam size is then directly related to the energy spread. In order to provide time-resolved energy spectra, a fraction of the OTR photons is sent onto a multichannel photomultiplier. The overall set-up is described, special focus is given to the design of the OTR screen with its synchrotron radiation shielding. The performance of the time-resolved measurements are discussed in detail. Finally, the limitations of the system, mainly due to radiation problems, are discussed.

TUPCH089	Investigations of OTR Screen Surfaces and Shapes	CTF3, radiation, focusing, diagnostics	1220
	C.P. Welsch, E. Bravin, T. Lefevre CERN, Geneva
	Optical transition radiation (OTR) has proven to be a flexible and effective tool for measuring a wide range of beam parameters, in particular the beam divergence and the transverse beam profile. It is today an established and widely used diagnostic method providing linear real-time measurements. Measurements in the CLIC Test Facility (CTF3) showed that the performance of the present profile monitors is limited by the optical acceptance of the imaging system. In this paper, two methods to improve the systems' performance are presented and results from measurements are shown. First, the influence of the surface quality of the OTR screen itself is addressed. Several possible screen materials have been tested to which different surface treatment techniques were applied. Results from the measured optical characteristics are given. Second, a parabolic-shaped screen support was investigated with the aim of providing an initial focusing of the emitted radiation and thus to reduce the problem of aperture limitation. Measured and calculated emission distributions are presented.

TUPCH094	THz Diagnostic for the Femtosecond Bunch Slicing Project at the Swiss Light Source	SLS, laser, storage-ring, CSR	1229
	V. Schlott, D. Abramsohn, P. Beaud, G. Ingold, P. Lerch PSI, Villigen
	Interaction of electron bunches with a femtosecond Ti:Sa laser beam along a modulator wiggler in the Swiss Light Source (SLS) storage ring results in an energy modulation of the electron beam on the length scale of the laser pulse. While high energy photon pulses (3 18 keV, ~ 100 fs long) are produced by an in-vacuum undulator (radiator) and used for time resolved experiments within the SLS femtosecond bunch slicing project, coherent synchrotron radiation (CSR) emitted by the adjacent bending magnet in the THz-regime is used for longitudinal slicing diagnostics and monitoring of slicing efficiency. This paper describes the simulation and layout of the THz-diagnostic beamline and presents first time and spectrally resolved measurements with the longitudinal slicing diagnostics, which has been set-up for the SLS “femto-slicing” project.

TUPCH096	High-intensity Bremsstrahlung Monitoring System for Photonuclear Technologies	photon, radiation, simulation, target	1235
	V.L. Uvarov, S.P. Karasyov, V.I. Nikiforov, R.I. Pomatsalyuk, V.A. Shevchenko, I.N. Shlyakhov, A.Eh. Tenishev, Yu.V. Zhebrovsky NSC/KIPT, Kharkov
	The realization of promising photonuclear technologies (a soft technology for medical isotope production, radioactive waste handling, activation analysis, etc) calls for the sources of high-energy (Egamma>10MeV) and high-intensity (>=10E03W/cm2) photons. These sources may by obtained by converting a beam from a high-current electron Linac into bremsstrahlung. The method of combined activation of a set of foils that have different energy thresholds of the (gamma,n) reactions is proposed to determine the space-energy characteristics of such radiation. In each energy range the geometrical characteristics of the bremsstrahlung flux are reconstructed from the foil surface gamma-activity distribution. The last one is determined through one-dimensional scanning of the foils by a specially designed detecting head that includes a linear matrix of 16 collimated semiconductor detectors (CdZnTe; 2x2x2,mm). A preliminary analysis of the system geometry and applicability of the method was performed by computer simulation based on the PENELOPE software. A developed PC based measuring system with CAMAC interface is described.

TUPCH097	Instrumentation and Operation of a Remote Operation Beam Diagnostics Lab at the Cornell Electron-positron Storage Ring	radiation, optics, positron, synchrotron	1238
	R. Holtzapple, J.S. Kern, P.J.S. Stonaha Alfred University, Alfred, New York B. Cerio Colgate University, Hamilton, New York M.A. Palmer Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
	Accelerator beam diagnostics are being modified at the Laboratory of Elementary Particle Physics (LEPP) at Cornell University for remote operation at nearby Alfred University. Presently, a streak camera used for longitudinal dynamics measurements on the Cornell Electron-Positron Storage Ring (CESR) is operational and measurements have been made from Alfred University [1]. In the near future, photomultiplier tube arrays for electron and positron vertical beam dynamics measurements will be remotely operated as well. In this paper, we describe instrumentation and operation of the remote beam diagnostics.

TUPCH098	Antiproton Momentum Distributions as a Measure of Electron Cooling Force at the Fermilab Recycler	antiproton, emittance, betatron, scattering	1241
	D.R. Broemmelsiek, S. Nagaitsev Fermilab, Batavia, Illinois
	The Fermilab Recycler is a fixed 8GeV kinetic energy storage ring located in the Fermilab Main Injector tunnel near the ceiling. Electron cooling of high-energy antiprotons has recently been demonstrated at the Recycler. Antiproton beam Schottky signals were used to measure the antiproton momentum distribution at equilibrium between a calibrated broadband diffusion source and electron cooling. The large Recycler momentum aperture, the dependence of the electron cooling force as a function of the antiproton momentum deviation and the calibrated diffusion source combine to give a unique spectral measurement of the antiproton momentum beam distribution.

TUPCH101	Modeling of Ultrafast Streak Cameras	simulation, cathode, acceleration, electromagnetic-fields	1250
	G. Huang, J.M. Byrd, J. Feng, H.A. Padmore, J. Qiang, W. Wan LBNL, Berkeley, California
	We present progress on modeling of streak camera with application to measurement of ultrafast phenomena. Our approach is based on treating the streak camera as a photocathode gun and applying modeling tools for beam optics, space charge, and electromagnetic fields. We use these models to compare with experimental results from a streak camera developed at the Advanced Light Source. Furthermore, we explore several ideas for achieving sub-100 fsec resolution.

TUPCH108	Characterization of the PEP-II Colliding-beam Phase Space by the Boost Method	emittance, positron, coupling, simulation	1262
	M. Weaver SLAC, Menlo Park, California W. Kozanecki CEA, Gif-sur-Yvette B.F. Viaud Montreal University, Montreal, Quebec
	We present a novel approach to characterize the colliding-beam phase space at the interaction point of the energy-asymmetric PEP-II B-Factory. The method exploits the fact that the transverse-boost distribution of e⁺ e^- –> mu+ mu- events reconstructed in the BaBar tracking system, reflects that of the colliding electrons & positrons. The average boost direction, when combined with the measured orientation of the luminous ellipsoid, determines the e⁺e^- crossing angles. Varying the horizontal direction of one beam with respect to the other in a controlled fashion allows to estimate the individual e⁺ and e^- horizontal IP beam sizes. The angular spread of the transverse boost vector provides an accurate measure of the angular spread of the incoming high-energy beam, confirming the presence of a significant beam-beam induced increase of this angular spread. In addition, the longitudinal dependence of the angular spread of the boost vector in the y-z plane allows to extract from the continuously-monitored boost distributions, a weighted average of the vertical IP beta-functions & emittances of the two beams representative of routine high-luminosity operation.

TUPCH109	Ion-related Phenomenon in UVSOR/UVSOR-II Electron Storage Ring	ion, vacuum, single-bunch, storage-ring	1265
	A. Mochihashi, K. Hayashi, M. Hosaka, M. Katoh, J. Yamazaki UVSOR, Okazaki Y. Hori KEK, Ibaraki Y. Takashima Nagoya University, Nagoya
	A vertical betatron tune shift depending on beam current under multibunch condition was observed in the UVSOR storage ring. Vertical tune increased as beam current decreased, and the slope of the tune shift depended on the condition of the vacuum in the ring. Such a change in vertical tune was explained by a change in the stability condition of trapped ions/* with the beam current. Based on a theoretical model*** that gives density of the trapped ions the experimental results were discussed via analytic and tracking calculations. Both the effect from the residual gas ions generated by scattering between high energy electrons and molecules and that from dissociated ions that come from secondary ionization processes have been discussed. In quest of the ion-related phenomenon in single-bunch condition, precise tune measurement has been also performed in the UVSOR-II storage ring. The experimental results in the single-bunch condition have been discussed. Precise measurement of vacuum pressure in the beam duct is a key issue of the ion-related phenomenon. A design of vacuum pressure measurement system via detecting residual gas fluorescence will be introduced in the presentation. R. D. Kohaupt. DESY Internal. Bericht No.H1-71/2 (1971). Y. Baconnier and G. Brianti. CERN Internal Report No.CERN/SPS/80-2(DI) (1980). **A. Mochihashi et al. Jpn. J. Appl. Phys. 44 (2005) 430.

TUPCH110	Upgrade of Main RF Cavity in UVSOR-II Electron Storage Ring	storage-ring, optics, controls, vacuum	1268
	A. Mochihashi, K. Hayashi, M. Hosaka, M. Katoh, J. Yamazaki UVSOR, Okazaki H. Suzuki Toshiba, Yokohama Y. Takashima Nagoya University, Nagoya
	The UVSOR electron storage ring, which is dedicated to a synchrotron radiation (SR) light source especially for VUV and Soft X-ray, has been improved at the beginning of 2003, and transverse emittance in the improved ring (UVSOR-II)* has been decreased from 165nm-rad to 60 and/or 27nm-rad. Users runs have been performed since September 2003 with 60nm-rad mode, and since then high brilliant SR beams have been supplied routinely for users. The 27nm-rad mode, however, was difficult to introduce to daily operation initially because Touschek lifetime was insufficient in such small emittance condition. To improve the beam lifetime and make full use of the SR beams, we have built new main RF cavity. The aim of the improvement was to increase momentum acceptance by increasing RF accelerating voltage; the previous cavity generated the voltage of 55kV, whereas the new one can generate 150kV in maximum without changing RF frequency (90.1MHz) and transmitter (20kW in maximum). The new cavity has been installed in the UVSOR-II in spring of 2005, and high power commissioning went on smoothly. Because of the improvement, from spring 2005 the UVSOR-II has switched the daily users run to 27nm-rad. *M. Katoh et al., in this conference.

TUPCH113	Construction of the ALPHA-X Photo-injector Cavity	gun, vacuum, cathode, injection	1277
	J. Rodier, T. Garvey LAL, Orsay D.A. Jaroszynski, V.M. Pavlov, Y.M. Saveliev, M. Wiggins USTRAT/SUPA, Glasgow M.J. de Loos, S.B. van der Geer PP, Soest
	We will describe the construction and low power testing of an RF cavity to be used as a photo-injector for the ALPHA-X project within the Department of Physics at the University of Strathclyde (UK). The gun is a two and a half cell S-band cavity, employing a metallic photo-cathode. RF power is coupled to the gun via a co-axial power coupler. The specification of the gun and the low power measurements made to achieve the correct mode frequency and field flatness will be presented.

TUPCH129	Conceptual Design of a 3rd Harmonic Cavity System for the LNLS Electron Storage Ring	storage-ring, damping, synchrotron, CBM	1316
	N.P. Abreu, O.R. Bagnato, R.H.A. Farias, M.J. Ferreira, C. Pardine, P.F. Tavares LNLS, Campinas
	The installation of a second RF cavity in the UVX electron storage ring at the Brazilian Synchrotron Light Laboratory (LNLS) at the end of 2003 brought about longitudinal instabilities driven by one of the HOMs of the new cavity. Even though the operational difficulties related to these unstable modes were successfully overcome by means of a combination of cavity tuning (using temperature and plunger adjustments) with phase modulation of the RF fields at the second harmonic of the synchrotron frequency, a more appropriate technique to avoid those problems is the use of higher harmonic cavities, which have the important advantage of providing damping of the longitudinal modes without increasing the energy spread, i.e., without compromising the longitudinal emittance. In this work we present the design of a passive higher harmonic cavity system optimized for operation at the LNLS storage ring. The parameters for a set of cavities as well as the analysis of some of the effects that they may introduce in the beam dynamics are presented. An overview of the technical aspects related to the project, construction and installation of the cavities in the storage ring is also presented.

TUPCH135	Characteristics of the PEFP 3 MeV RFQ	rfq, dipole, quadrupole, coupling	1334
	H.-J. Kwon, Y.-S. Cho, J.-H. Jang, H. S. Kim, K.T. Seol KAERI, Daejon
	A four-vane type 3 MeV, 350 MHz RFQ (Radiofrequency Quadrupole) has been developed as a front end part of PEFP (Proton Engineering Frontier Project) 100 MeV accelerator. After the completion of field tuning and high power conditioning at reduced duty, the initial operation of the RFQ with beam was carried out. During the initial test period, several parameters related with the RF and beam were measured to characterize the performance of the RFQ. Based on these measurements, several suggestions for further system improvement were proposed. In this paper, the initial test results are discussed and the suggestions for the system improvement are summarized.

TUPCH136	Phase Measurement and Compensation System in PLS 2.5 GeV Linac for PAL-XFEL	linac, feedback, klystron, XFEL	1337
	W.H. Hwang, J. Choi, Y.J. Han, J.Y. Huang, H.-G. Kim, S.-C. Kim, I.S. Ko, W.W. Lee PAL, Pohang, Kyungbuk
	In PAL, We are preparing the 3.7 GeV PALXFEL project by upgrading the present 2.5GeV Linac. In present PLS Linac, the specifications of the beam energy spread and rf phase are 0.6%(peak) and 3.5 degrees(peak) respectively. And the output power of klystron is 80 MW at the pulse width of 4 ? and the repetition rate of 10 Hz. In XFEL, the specifications of the beam energy spread and rf phase are 0.03%(rms) and 0.01 degrees(rms) respectively. We developed an analogue and a digital phase measurement and rf phase compensation system for stable beam quality. This paper describes the microwave system for the PALXFEL and the rf phase measurement and phase compensation system.

TUPCH146	The Interactions of Surface Damage on RF Cavity Operation	site, vacuum, RF-structure, controls	1361
	J. Norem, A. Hassanein, Z. Insepov ANL, Argonne, Illinois A. Bross, A. Moretti, Z. Qian Fermilab, Batavia, Illinois D. Li, M.S. Zisman LBNL, Berkeley, California R.A. Rimmer Jefferson Lab, Newport News, Virginia D.N. Seidman, K. Yoon NU, Evanston, Illinois Y. Torun IIT, Chicago, Illinois
	Studies of low frequency RF systems for muon cooling has led to a variety of new techniques for looking at dark currents, a new model of breakdown, and, ultimately, a model of RF cavity operation based on surface damage. We find that cavity behavior is strongly influenced by the spectrum of enhancement factors on field emission sites. Three different spectra are involved: one defining the initial state of the cavity, the second determined by the breakdown events, and the third defining the equilibrium produced as a cavity operates at its maximum field. We have been able to measure these functions and use them to derive a wide variety of cavity parameters: conditioning behavior, material, pulse length, temperature, vacuum, magnetic field, pressure, gas dependence. In addition we can calculate the dependence of breakdown rate on surface field and pulse length. This work correlates with data from Atom Probe Tomography. We will describe this model and new experimental data.

TUPCH155	2D and 1D Surface Photonic Band Gap Structures for Accelerator Applications	radiation, plasma, SLAC, undulator	1388
	I.V. Konoplev, A.W. Cross, W. He, P. MacInnes, A. Phelps, C.W. Robertson, K. Ronald, C.G. Whyte USTRAT/SUPA, Glasgow
	High frequency (26.5GHz to 40GHz), high power (tens of MW) microwave sources are required for cavity testing and conditioning applications in accelerators such as CLIC. The first study of microwave radiation from a co-axial Free-Electron Maser (FEM) based on a two-mirror cavity formed by a 2D Surface Photonic Band Gap (SPBG) structure (input mirror 10.4cm) and 1D SPBG structure (output mirror 10cm) is presented. The electron beam source consisted of a magnetically insulated plasma flare emission carbon cathode. Application of a 450kV voltage pulse of duration ~250ns across the cathode and grounded anode resulted in the production of a 7.0cm diameter annular electron beam of current ~1500A. The output radiation power from the FEM was measured using a Ka-band horn with 60dB of attenuation in front of a microwave detector located at a distance of 1.5m from the output window. By integrating the microwave power measured at the detector over the radiation pattern a total power of 50 (±10) MW corresponding to an efficiency of ~9% was calculated. The location of the operating frequency was found to lie between 35GHz and 39GHz, which agrees with theoretically predicted frequency of 37.2GHz.

TUPCH156	Design and Simulation of a Cusp Gun for Gyro-amplifier Application in High Frequency RF Accelerators	gun, cathode, simulation, cyclotron	1391
	D.H. Rowlands, A.W. Cross, W. He, A. Phelps, E.G. Rafferty, C.W. Robertson, K. Ronald, J. Thomson, C.G. Whyte, A.R. Young USTRAT/SUPA, Glasgow
	Gyro-amplifiers have potential as the high frequency RF drivers for particle accelerators. They require relativistic electron beams with low velocity spread and with a high fraction of the electron energy associated with the cyclotron motion. For harmonic operation and mode control an axis-encircling beam is desirable. The passage of an electron beam through a non-adiabatic magnetic field reversal (cusp) converts part of the electron beam's axial velocity into axis-encircling transverse velocity. A cusp-based electron beam forming system, yielding a 10MW, 150kV, 70A axis-encircling beam will be presented. This cusp gun is being designed as the electron beam source for a microwave gyro-amplifier that is relevant for high frequency accelerator applications. The latest results from numerical simulations and experiments will be presented and compared.

TUPCH159	High Power Waveguide Switching System for SPring-8 Linac	klystron, linac, vacuum, injection	1397
	T. Taniuchi, T. Asaka, H. Dewa, H. Hanaki, T. Kobayashi, A. Mizuno, S. Suzuki, H. Tomizawa, K. Yanagida JASRI/SPring-8, Hyogo-ken A. Miura Nihon Koshuha Co., Ltd., Yokohama
	A vacuum waveguide switch has been developed to build a backup system of an RF source for the electron injector system and the klystron drive line in the SPring-8 linac. A high power test of the waveguide switch was carried out, and the maximum RF power of 62 MW in peak, 1μsecond in pulse width and 10 pps in repetition rate was achieved without serious problems in RF and vacuum characteristics. The backup system utilizing this waveguide switch has been installed in the electron injector system.

TUPCH160	Novel Conception of Beam Temperature in Accelerator and Applications	klystron, emittance	1400
	D. Dong IHEP Beijing, Beijing
	In this paper, we will introduce a novel conception of beam temperature in accelerator, discuss the calculation method. And finally the author will show an example on the beam temperature in a klystron.

TUPCH166	Multi-megawatt Harmonic Multiplier for Testing High-gradient Accelerator Structures	klystron, SLAC, gun, simulation	1414
	V.P. Yakovlev Omega-P, Inc., New Haven, Connecticut J.L. Hirshfield Yale University, Physics Department, New Haven, CT
	Basic studies for determining the RF electric and magnetic field limits on surfaces of materials suitable for accelerator structures for a future multi-TeV collider, and for the testing of the accelerator structures and components themselves, require stand-alone high-power RF sources at several frequencies, from 10 to 45 GHz. A relatively simple and inexpensive two-cavity harmonic multiplier at 22.8, 34.3, or 45.7 GHz is suggested to be the stand-alone multi-MW RF power source for this application. The design is based on the use of an existing SLAC electron gun, such as the XP3 gun, plus a beam collector as used on the XP3 klystron. RF drive power would be supplied from an 11.4 GHz, 50 or 75 MW SLAC klystron and modulator, and a second modulator would be used to power the gun in the multiplier. Preliminary computations show that 64, 55, and 47 MW, respectively, can be realized in 2nd, 3rd, and 4th harmonic multipliers at 22.8, 34.3, and 45.7 GHz using 75 MW of X-band drive power.

TUPCH178	Deposition of Non Evaporable Getter (NEG) Films on Vacuum Chambers for High Energy Machines and Synchrotron Radiation Sources	vacuum, cathode, synchrotron, controls	1435
	P. Manini, A. Bonucci, A. Conte, S. Raimondi SAES Getters S.p.A., Lainate
	Non Evaporable Getter (NEG) films, sputter deposited onto the internal surfaces of vacuum chambers reduce thermal out-gassing and provide conductance-free distributed pumping ability, allowing the achievement of very low pressure inside narrow and conductance limited chambers, like Insertion Devices. NEG films do show additional interesting features, like low secondary electron yield and low gas de-sorption rates under ions, electrons and photons bombardment. They seem therefore ideal to reduce electron multi-pacting and dynamic gas de-sorption induced beam instabilities in high energy machines. This paper presents SAES getters experience in the NEG coating of chambers of different geometries and sizes for a variety of projects related to high energy machines and synchrotron radiation facilities. Examples of applications, as well as most common issues related to chambers preparation, film deposition, characterization and quality control, are given. Areas where further work is still necessary to fully take advantage of NEG film properties will be also discussed.

TUPCH179	R&D on Copper Beam Ducts with Antechambers and Related Vacuum Components	KEKB, wiggler, vacuum, photon	1438
	Y. Suetsugu, H. Hisamatsu, K.-I. Kanazawa, K. Shibata, M. Shimamoto, M. Shirai KEK, Ibaraki
	A beam duct with antechambers is able to reduce the effect of photoelectrons and, as a result, to suppress the electron cloud effect of positron or proton beam. It will be adopted for a future high current positron/proton rings and also a damping ring of a linear collider. Copper beam ducts with one or two antechambers were manufactured for test and the feasibility was studied. The test chambers were then installed into the KEK B-factory positron ring and the performance was investigated with a beam current up to 2000 mA. The temperature, the pressure and the electron density in the beam channel were measured during the beam operation. The photoelectron, for example, was found to be well suppressed as expected compared to that of a simple circular beam duct. The related vacuum components, such as a connection flange, a bellows chamber and a gate valve with the same cross section to the beam duct, were also developed and tested together with the beam duct.

TUPCH187	DSP-based Low Level RF Control as an Integrated Part of DOOCS Control System	controls, feedback, linac, DESY	1450
	V. Ayvazyan, A. Brandt, O. Hensler, G.M. Petrosyan, L.M. Petrosyan, K. Rehlich, S. Simrock, P. Vetrov DESY, Hamburg
	The Distributed Object Oriented Control System (DOOCS) has been developed at DESY as a control system for TTF/VUV-FEL. The DSP based low level RF control system is one of the main subsystems of the linac. Several DOOCS device servers and client applications have been developed to integrate low level RF control into the TTF/VUV-FEL control system. The DOOCS approach defines each hardware device as a separate object and this object is represented in a network by a device server, which handles all device functions. A client application can have access to the server data using the DOOCS application programming interface. A set of generic and specially devoted programs provide the tools for the operators to control the RF system. The RF operation at the linac is being automated by the implementation of DOOCS finite state machine servers.

TUPCH188	Phase Stability of the Next Generation RF Field Control for VUV- and X-ray Free Electron Laser	klystron, controls, free-electron-laser, laser	1453
	F. Ludwig, M. Hoffmann, H. Schlarb, S. Simrock DESY, Hamburg
	For pump and probe experiments at VUV- and X-ray free electron lasers the stability of the electron beam and timing reference must be guaranteed in phase for the injector and bunch compression section within a resolution of 0.01 degree (rms) and in amplitude within 1 10-4 (rms). The performance of the field detection and regulation of the acceleration RF directly influences the phase and amplitude stability. In this paper we present the phase noise budget for a RF-regulation system including the noise characterization of all subcomponents, in detail down-converter, ADC sampling, vector-modulator, master oscillator and klystron. We study the amplitude to phase noise conversion for a detuned cavity. In addition we investigate the beam jitter induced by these noise sources within the regulation and determine the optimal controller gain. We acknowledge financial support by DESY Hamburg and the EUROFEL project.

TUPCH189	FPGA-based RF Field Control at the Photocathode RF Gun of the DESY VUV-FEL	controls, gun, FIR, DESY	1456
	E. Vogel, W. Koprek, P. Pucyk DESY, Hamburg
	At the DESY Vacuum Ultraviolet Free Electron Laser (VUV-FEL) bunch peak current and the SASE effect are (amongst other parameters) sensitive to beam energy and beam phase variations. The electron bunches are created in an rf gun, which does not have field probes. Variations of the gun rf field cause beam energy and phase variations. They have a significant influence on the overall performance of the facility. DSP based rf field control used previously was only able to stabilize the rf output of the klystron. This was due to the lack of processing power and the over-all loop delay. The controller was not able to provide satisfactory rf field stability in the gun. Replacing the DSP hardware by the new FPGA-based hardware Simulation Controller (SimCon), we are able to reduce the latency within the digital part significantly allowing for higher loop gain. Furthermore SimCon provides sufficient processing power for calculating a probe signal from the forward and reflected power as input for PI and adaptive feed forward (AFF) control. In this paper we describe the algorithms implemented and the gun rf field stability obtained.

TUPLS002	Dust Macroparticles in HERA and DORIS	vacuum, radiation, storage-ring, simulation	1486
	A. Kling DESY, Hamburg
	Charged dust macroparticles are considered as sources of sudden beam lifetime breakdowns detected in many electron storage rings. This phenomenon is still observed in HERA, although the distributed ion pumps, which were previously identified as dust particle sources, have been removed. We report on the observations of trapped dust during the last period of electron operation and present a detailed model of dust macroparticle dynamics in the HERA e-ring and in DORIS with particular emphasis on stability and possible trapping processes.

TUPLS003	A Perfect Electrode to Suppress Secondary Electrons inside the Magnets	dipole, positron, KEKB, quadrupole	1489
	L. Wang, M.T.F. Pivi SLAC, Menlo Park, California H. Fukuma, S.-I. Kurokawa KEK, Ibaraki G.X. Xia DESY, Hamburg
	Electron cloud due to multipacting in the positron ring of B-factories is one of the limitations on the machine performance. Electron cloud in the drift region can be suppressed by solenoid. However, solenoid doesn't work inside a magnet. Numerical studies show that there is strong multipacting in the dipole magnet of the B-factory positron ring. Electrons also can be trapped inside quadrupole and sextupole magnets. The electron cloud from the dipole magnet and wiggler in the positron damping ring of the ILC is a critical limitation on the choice of damping ring circumference, which directly results in a choice of two 6km rings as the baseline for the positron damping ring. Various electrodes have been studied using the program CLOUDLAND. Our studies show that a wire type of electrode with a few hundred voltages works perfectly to kill the secondary electrons inside various magnets.

TUPLS061	Design of a Low Energy Electron Cooler for the Heidelberg CSR	ion, CSR, dipole, target	1630
	H. Fadil, M. Grieser, D. Orlov, A. Wolf MPI-K, Heidelberg
	The electrostatic Cryogenic Storage Ring (CSR) is currently being designed at MPI-K in Heidelberg. This ring will utilize electrostatic deflectors and focusing elements, and will store ions with kinetic energies in the range 20~300 keV (E/Q) to be mainly utilized in atomic and molecular physics experiments. The CSR will be equipped with a compact magnetic electron cooler, which will serve the double purpose of phase space compression of the stored ion beam as well as an electron target for recombination experiments. The cryogenic photocathode source, developed for the Heidelberg TSR, will be used to provide extremely cold magnetically guided electron beams. The maximum cooling electron energy is 165 eV and the usual operation energy for 20 keV protons will be about 10 eV. The cooler will fit in the 2.8 m straight section of the ring. The device will be installed inside the outer vacuum chamber of the CSR, and the magnetic confinement of the electrons will be provided with high temperature superconducting coils. The design of the magnets of the CSR electron cooler will be presented in this paper.

TUPLS062	Cooling Rates at Ultra-low Energy Storage Rings	ion, storage-ring, simulation, antiproton	1633
	C.P. Welsch, C.P. Welsch CERN, Geneva A.V. Smirnov JINR, Dubna, Moscow Region
	Electrostatic low-energy storage rings have proven to be a highly flexible tool, able to cover experiments from a variety of different fields ranging from atomic, nuclear and molecular physics to biology and chemistry. Future machines will decisively rely on efficient electron cooling down to electron energies as low as some eV, posing new challenges to the cooler layout and operation. The BETACOOL code has already been successfully applied for the layout and optimization of a number of different electron coolers around the world. In this contribution, the results from calculations of the cooling rates at future low-energy machines equipped with an internal target like the Ultra-low energy Storage Ring (USR) at the Facility for Low-energy Antiproton and Ion Research (FLAIR) are presented.

TUPLS063	Layout of the USR at FLAIR	storage-ring, ion, antiproton, positron	1636
	C.P. Welsch, C.P. Welsch CERN, Geneva M. Grieser, J. Ullrich, A. Wolf MPI-K, Heidelberg
	The Facility for Low-energy Antiproton and Ion Research (FLAIR) and a large part of the wide physics program decisively rely on new experimental techniques to cool and slow down antiprotons to 20 keV, namely on the development of an ultra-low energy electrostatic storage ring (USR). The whole research program connected with anti-matter/matter interactions is only feasible if such a machine will be realized For the USR to fulfil its key role in the FLAIR project, the development of novel and challenging methods and technologies is necessary: the combination of the electrostatic storage mode with a deceleration of the stored ions from 300 keV to 20 keV, electron cooling at all energies in both longitudinal and transverse phase-space, bunching of the stored beam to ultra-short pulses in the nanosecond regime and the development of an in-ring reaction microscope for antiproton-matter rearrangement experiments. In this contribution, the layout and the expected beam parameters of the USR are presented and its role within FLAIR described. The machine lattice and the cooler parameters are summarized.

TUPLS064	Design and Commissioning of a Compact Electron Cooler for the S-LSR	cathode, gun, proton, ion	1639
	H. Fadil, S. Fujimoto, A. Noda, T. Shirai, H. Souda, H. Tongu Kyoto ICR, Uji, Kyoto T. Fujimoto, S.I. Iwata, S. Shibuya AEC, Chiba M. Grieser MPI-K, Heidelberg K. Noda NIRS, Chiba-shi I.A. Seleznev, E. Syresin JINR, Dubna, Moscow Region
	The ion cooler ring S-LSR has been constructed and commissioned in October 2005. The ring successfully stored a 7 MeV proton beam. The S-LSR is equipped with a compact-electron cooler which has a cooling solenoid length of 0.8 m, a toroid bending radius of 0.25 m and maximum magnetic field in the cooling section of 0.5 kG. The commissioning of the electron cooler was carried out with successful observation of both longitudinal and horizontal cooling of the proton beam. By varying the electric potential on the Pierce electrode in the gun, we have investigated the possibility of generating a hollow shaped electron beam, and studied its effect on the electron cooling process. Also the effect of the electrostatic deflector, installed in the toroid section in order to compensate the drift motion of the secondary electrons, was investigated. The design and results of the commissioning of the compact electron cooler are presented.

TUPLS065	Beam Commissioning of Ion Cooler Ring, S-LSR	ion, proton, vacuum, laser	1642
	T. Shirai, S. Fujimoto, M. Ikegami, A. Noda, H. Souda, M. Tanabe, H. Tongu Kyoto ICR, Uji, Kyoto H. Fadil MPI-K, Heidelberg T. Fujimoto, H. Fujiwara, S.I. Iwata, S. Shibuya AEC, Chiba I.N. Meshkov, I.A. Seleznev, A.V. Smirnov, E. Syresin JINR, Dubna, Moscow Region K. Noda NIRS, Chiba-shi
	S-LSR is a new ion cooler ring constructed in Kyoto University. The circumference is 22.557 m and the maximum magnetic rigidity is 1 Tm. The constructiion and the vacuum baking had been finished in September, 2005. The beam commissioning was started since October, 2005. The injected beam is 7 MeV proton from the existing linac. The beam circulation test and the electron beam cooling were carried out successfully and the beam information and the characteristics of the ring were measured. One of the subjects of S-LSR is a realization of the crystalline beams using the electron and laser cooling. The lattice of S-LSR was designed to suppress the beam heating as much as possible and we also present such measurement results in this paper.

TUPLS066	Peculiarities of Electron Cooler Operation and Construction at Ultra Low Energy in an Electrostatic Ring	cathode, target, ion, KEK	1645
	E. Syresin JINR, Dubna, Moscow Region
	Few projects of electrostatic rings with electron cooler are discussed now. Electron cooling at low electron energy of 10 eV was realized at the KEK electrostatic ring. The electron cooling permits to suppress the ion multi scattering on residual gas atoms and allows increasing the ion lifetime. Peculiarities of an electron cooler operation and construction at ultra low energy in an electrostatic ring are considered. The cooler gun operation regime is cardinally changed at a reduction of the electron energy to a value comparable with a cathode work function. A virtual cathode and ohmic resistance of cathode emitter give an input in beam formation at ultra low energy. Effective electron cooling of heavy atomic and bimolecular ions at mass of 100-1000 is reached at a small photocathode diameter of 1 mm and a high magnetic expansion factor of 10^-1000. The electron cooler construction has traditional design in KEK electrostatic ring. The cooler construction can be simplified at a small circumference of electrostatic ring. Straight cooler schemes without toroidal magnets permit to reduce ring space required for electron cooler.

TUPLS067	Status of the HESR Electron Cooler Design Work	antiproton, target, gun, collider	1648
	D. Reistad, T. Bergmark, O. Byström, B. Gålnander, S. Johnson, T. Johnson, T. Lofnes, G. Norman, T. Peterson, K. Rathsman, L. Westerberg TSL, Uppsala H. Danared MSL, Stockholm
	The electron energy of the HESR electron cooler shall be variable from 450 keV to 4.5 MeV. Furthermore, the design shall not exclude a further upgrade to 8 MeV. Operation of the HESR in a collider mode, which requires electron cooling of both protons and antiprotons traveling in opposite directions, is an interesting option. The status of the technical design of the HESR electron cooling system will be presented.

TUPLS068	LEIR Electron Cooler Status	ion, gun, vacuum, injection	1651
	G. Tranquille, V. Prieto, R. Sautier CERN, Geneva A.V. Bubley, V.V. Parkhomchuk BINP SB RAS, Novosibirsk
	The electron cooler for LEIR is the first of a new generation of coolers being commissioned for fast phase space cooling of ion beams in storage rings. It is a state-of-the-art cooler incorporating all the recent developments in electron cooling technology (adiabatic expansion, electrostatic bend, variable density electron beam…) and is designed to deliver up to 600 mA of electron current for the cooling and stacking of Pb⁵⁴⁺ ions in the frame of the ions for LHC project. In this paper we present our experience with the commissioning of the new device as well as the first results of ion beam cooling with a high-intensity variable-density electron beam.

TUPLS069	Performance of Fermilab's 4.3 MeV Electron Cooler	antiproton, gun, cathode, focusing	1654
	A.V. Shemyakin, A.V. Burov, K. Carlson, M. Hu, T.K. Kroc, J.R. Leibfritz, S. Nagaitsev, L.R. Prost, S.M. Pruss, G.W. Saewert, C.W. Schmidt, M. Sutherland, V. Tupikov, A. Warner Fermilab, Batavia, Illinois
	A 4.3 MeV DC electron beam is used to cool longitudinally an antiproton beam in the Fermilab's Recycler ring. The cooling rate is regulated either by variation of the electron beam current up to 0.5 A or by a vertical separation of beams in the cooling section. The paper will describe steps that provided a stable operation and present the status of the cooler.

TUPLS080	The Proposed 2 MeV Electron Cooler for COSY-Juelich	COSY, acceleration, gun, target	1684
	J. Dietrich FZJ, Jülich V.V. Parkhomchuk BINP SB RAS, Novosibirsk
	The design, construction and installation of a 2 MeV electron cooling system for COSY-Juelich is proposed to further boost the luminosity even with strong heating effects of high-density internal targets. In addition the design of the 2 MeV electron cooler for COSY is intended to test some new features of the high energy electron cooler for HESR at FAIR/GSI. The design of the 2 MeV electron cooler will be accomplished in cooperation with the Budker Institute of Nuclear Physics in Novosibirsk, Russia. Starting with the boundary conditions of the existing electron cooler at COSY the requirements and a first general scheme of the 2 MeV electron cooler are described.

TUPLS083	A Low Energy Accumulation Stage for a Beta-beam Facility	ion, injection, accumulation, SPS	1693
	A. Källberg, A. Simonsson MSL, Stockholm M. Lindroos CERN, Geneva
	The EU supported EURISOL Design Study encompasses a beta-beam facility for neutrino physics. Intense electron (anti-)neutrino beams are in such a machine generated through the decay of radioactive ions in a high energy storage ring. The two main candidate isotopes for the generation of a neutrino and an anti-neutrino beam are 6He²⁺ and 18Ne¹⁰⁺. The intensities required are hard to reach, in particular for the neon case. A possible solution to increase the intensity is to use an accumulator ring with an electron cooler. Critical parameters such as cooling times and current limitations due to space charge and tune shifts are presently being optimized. We will in this presentation give an overview of the low energy accumulation stage and review recent work on this option.

TUPLS086	Charge Breeding Exploration with the MAXEBIS	ion, GSI, HITRAP, injection	1702
	H.Z. Zimmermann LMU, Garching R. Becker, M.K. Kleinod IAP, Frankfurt-am-Main O.K. Kester GSI, Darmstadt
	The demand of exotic ions prior to their injection into an accelerator has driven the development of the charge breeding method. Existing facilities like REX-ISOLDE or ISAC at TRIUMF are already using a charge state booster for the post acceleration of radioactive ions. Planned facilities like EURISOL for instance have identified the need of a breeding system. In order to be comparable to the efficiency to a brut force acceleration employing stripper, the efficiency of a charge breeder has to be maximized and the breeding time has to be shortened comparing the existing breeder systems. Therefore the exploration and optimization of the charge state breeding is mandatory and supported by the EU. The Frankfurt MAXEBIS has been modified within the past years towards high current electron beam and external injection of alkaline ions by a surface ionisation source. The electron gun, the inner electrode structure and the collector of the MAXEBIS have been modified. The system has been shipped to GSI and re-assembled. The goals of the following experiments will be systematic studies of the breeding efficiency. The new setup and first experimental results will be presented.

TUPLS089	Pseudospark-sourced Beams of Electrons and Ions	cathode, acceleration, brightness, ion	1711
	A.W. Cross, W. He, A. Phelps, K. Ronald, H. Yin USTRAT/SUPA, Glasgow
	A pseudospark discharge has undergone intensive studies with regard to its unusual and interesting discharge properties during last fifteen years. The pseudospark attracts significant attention from diverse fields such as pulsed-power switching, electron beam generation, free electron masers, ion beam generation, extreme-ultraviolet radiation sources, microthrusters and pseudospark-triggered wakefield acceleration. This paper will present experiments and measurements of pseudospark-sourced electron and ion beams for accelerators. Pulsed electron beams with current intensity over 108 Am-2, high brightness up to 1012A m-2 rad-2 and emittance of tens of mm mrad were produced from a multi-gap pseudospark discharge. The transportation of the pseudospark electron beams is also investigated in order to produce high peak current, high quality, short (~100 picosecond) or long duration (2~100ns) high-brightness electron beam pulses. Recent results from a high current density pseudospark-produced ion beam experimentally investigated with hydrogen gas will be presented.

TUPLS092	Implementations on the RF Charge Breeder Device BRIC with Test Measurements	ion, MCP, extraction, simulation	1717
	V. Variale, A. Boggia, T. Clauser, A.C. Rainò, V. Valentino INFN-Bari, Bari P.A. Bak, G.I. Kuznetsov, B.A. Skarbo, M.A. Tiunov BINP SB RAS, Novosibirsk
	The Radioactive Ion Beam (RIB) production with ISOL technique should require a charge breeder device to increase the ion acceleration efficiency and reduce greatly the production cost. The "charge state breeder" BRIC (BReeding Ion Charge) is based on an EBIS source and it is designed to accept RIB with charge state +1 and increase their charge state up to +n. BRIC has been developed at the INFN section of Bari (Italy) during these last 3 years with very limited funds and it has been assembled at the LNL (Italy) laboratory. BRIC could be considered as a solution for the charge state breeder of the SPES project under study also at the LNL. The new feature of BRIC, with respect to the classical EBIS, is given by the insertion, in the ion drift chamber, of a Radio Frequency (RF) - Quadrupole aiming to filtering the unwanted masses and then making a more efficient containment of the wanted ions. The RF test measurements seem confirm, as foreseen by simulation results* that a selective containment can be obtained. Most accurate measurements, however, are needed and for that implementations of the system have been carried out. *V. Variale and M. Claudione. "BRICTEST: a code for charge breeding simulations in RF quadrupolar field", NIM in Phys. res. A 543 (2005) 403-414.

TUPLS103	Further Development of a Low Inductance Metal Vapor Vacuum Arc (LIZ-MeVVA) Ion Source	plasma, ion, extraction, vacuum	1738
	B.M. Johnson APS, Ridge E. Garate, R. McWilliams, J.P. Sprunck, A. van Drie University of California IIrvine, Irvine, California A. Hershcovitch BNL, Upton, Long Island, New York
	A Low Impedance Z-Discharge Metal Vapor Vacuum Arc (LIZ-MeV) ion source* is being explored as an alternate pre-injector for the Brookhaven Relativistic Heavy Ion Collider (RHIC). With the vacuum arc operating at tens of kiloamperes and an aluminum electrode, LIZ-MeV has been run in two regimes: an LC dominated "ringing" arc of period 4.1 microseconds, which decays after about 6 cycles, and a 1-3 microsecond wide "pulsed" arc, where a small series resistance has been added to critically damp ringing. Metal ions are extracted from the plasma using a two-grid system with a triggered, variable-delay voltage of up to 10 kV. Time-of-Flight (TOF) measurements are taken using a Faraday cup located at the end of a 15-76 cm drift tube. TOF measurements from both arc regimes have been obtained suggesting generation of about a billion ions per pulse of charge states +1 and +2, and occasionally +3 states. TOF results are compared with simple theoretical models. *B. M. Johnson, et al. Two approaches to electron beam enhancement of the metal vapor vacuum arc ion source. Laser and Particle Beams 21, 103 (2003).

TUPLS105	Sputter Probes and Vapor Sources for ECR Ion Sources	ion, plasma, cathode, ion-source	1744
	M. Cavenago, A. Galatà, M. Sattin INFN/LNL, Legnaro, Padova T. Kulevoy, S. Petrenko ITEP, Moscow
	Sputter probes are a promising method for injecting controlled quantities of metallic elements inside ECRIS ion source, provided that sputter rate can be controlled, so that high charge states and low sample consumption rate will be attained. Moreover pressure at the probe and inside source should be different. With a simple differential pumping scheme and a sputter probe at 25 mm from ECRIS plasma, a 200 nA current of 120Sn¹⁸⁺ was easily obtained. Typical results (for Sn and Ti) of an inductively heated rf oven are discussed for comparison. Improvements of sputter probe concept and geometry are also described.

TUPLS118	Injection System Design for the CSNS/RCS	injection, proton, emittance, linac	1783
	J. Tang, Y. Chen, Y.L. Chi, Y.L. Jiang, W. Kang, J.B. Pang, Q. Qin, J. Qiu, L. Shen, S. Wang IHEP Beijing, Beijing J. Wei BNL, Upton, Long Island, New York
	The CSNS injection system is designed to take one uninterrupted long drift in one of the four dispersion-free straight sections to host all the injection devices. Painting bumper magnets are used for both horizontal and vertical phase space painting. Closed-orbit bumper magnets are used for facilitating the installation of the injection septa and decreasing proton traversal in the stripping foil. Even with large beam emittance of about 300 pmm.mrad used, BSNS/RCS still approaches the space charge limit during the injection/trapping phase for the accumulated particles of 1.9*10¹³ and at the low injection energy of 80 MeV. Uniform-like beam distribution by well-designed painting scheme is then obtained to decrease the tune shift/spread. ORBIT code is used for the 3D simulations. Upgrading to higher injection energy has also been considered.

WEYPA01	Beam Delivery System in ILC	linac, quadrupole, feedback, luminosity	1852
	G.A. Blair Royal Holloway, University of London, Surrey
	The presentation will review the challenges of this key ILC sub-system in terms of beam performances, machine protection system, collimation, interaction with the detector and compare them with the achievements in SLC and FFTB. It will then present the world-wide organization to define and make the necessary R&D for the design, beam simulations and benchmarking in tests facilities, especially the ATF2 facility under construction at KEK. It will explore the major issues both from the beam dynamics and the technological point of view, as well as the plans foreseen and the schedule to address them. It will finally analyze the possible upgrade in energy together with the possible limitations and associated issues.
	Transparencies

WEYPA02	Damping Rings towards Ultra-low Emittances	damping, wiggler, emittance, kicker	1857
	S. Guiducci INFN/LNF, Frascati (Roma)
	The presentation will review the various designs of Damping Rings to achieve ultra-low emittance beams in Linear Colliders (ILC and CLIC) pointing out the major issues both from the beam dynamics and the technological point of vue and comparing the required performances with the one achieved in SLC or FFTB. It will then present the design, beam simulations, benchmarking and performances already achieved in test facilities, especially the ATF1 facility developed and operated at KEK. Finally, it will present future R&D plans and schedule in terms of beam performances, beam stability and technological development as well as the world-wide organization to achieve them.
	Transparencies

WEXFI02	Observation and Modeling of Electron Cloud Instability	RHIC, KEK, LHC, proton	1887
	K.C. Harkay ANL, Argonne, Illinois
	This presentation will review experimental results and the state of the art in the analysis and simulation of the electron cloud instability in hadron and positron storage rings.
	Transparencies

WEOFI02	RF Phase Modulation Studies at the LNLS Electron Storage Ring	damping, synchrotron, single-bunch, storage-ring	1905
	N.P. Abreu, R.H.A. Farias, P.F. Tavares LNLS, Campinas
	In this work we present a set of measurements of the effectiveness of RF phase modulation on the second harmonic of the RF frequency as a mechanism to damp longitudinal coupled-bunch instabilities. We also propose a theoretical model of the damping mechanism, in which the increase of the spread in synchrotron frequencies inside the bunches produced by phase modulation is responsible for damping the centroid dipolar coherent motion caused by an external excitation, which could be a Higher Order Mode (HOM) of the RF cavities driving the coupled bunch motion. We measured the coherent synchrotron oscillation damping of a single bunch under two circumstances, with and without phase modulation, and determined the amount of extra damping due to the modulation. With this experiment we could also measure the frequency of small oscillations around the stable islands formed by phase modulation and its behavior when the RF phase modulation amplitude and frequency are changed. We performed measurements of Beam Transfer Function (BTF) to observe the effects of phase modulation over the stable area for coherent oscillations and compared the results with a theoretical model.
	Transparencies

WEPCH006	Comparison between Simulations and Measurements of Low Charge Electron Bunch in the ELSA Facility	simulation, laser, quadrupole, ELSA	1927
	J.-L. Lemaire, A.B. Binet, A.B. Bloquet, D. Guilhem, V. Le Flanchec, S. Pichon CEA, Bruyeres-le-Chatel
	Dedicated focal spot size measurements carried out at the ELSA electron linear accelerator facility have provided detailed data which are suitable for benchmarking of different simulation codes for high charge bunch beam acceleration issued from an RF photo-injector source. We present some characteristic features of bunched electron beam propagation from beam formation at the photo-cathode to acceleration through RF cavities until the final focussing on a target, by using numerical simulations obtained with MAGIC, PARMELA, MAFIA, PARTRAN tool box codes. The challenges for the planned benchmarking are discussed.

WEPCH013	Electron Transport Line Optimization using Neural Networks and Genetic Algorithms	injection, booster, synchrotron, storage-ring	1948
	D. Schirmer, T. Buening, P. Hartmann, D. Mueller DELTA, Dortmund
	Methods of computational intelligence (CI) were investigated to support the optimization of the electron transfer efficiency from the booster synchrotron BoDo to the electron storage ring DELTA. Neural networks and genetic algorithms were analysed alternatively. At first both types of methods were trained on the basis of a theoretical model of the transport line. After the training various algorithms were used to improve the magnet settings of the real transport line elements with respect to the electron transfer efficiency. The results of different strategies are compared and prospects as well as limitations of CI-methods to the application of typical optimization problems in accelerator operation are discussed.

WEPCH015	Measurement and Correction of Dispersion in the VUV-FEL	undulator, quadrupole, simulation, DESY	1951
	E. Prat, W. Decking, T. Limberg DESY, Hamburg
	Increase in transverse beam size in the undulator caused by dispersive effects is one of the major limitations for the operation of FLASH, the VUV-FEL at DESY. Sources of the (spurious) dispersion are field errors and stray magnet fields in the undulator beam line as well as spurious dispersion created upstream of the undulator by, for instance, rf coupler kicks, magnet misalignments and field errors. The impact of these errors on dispersion generation depends on the actual operating conditions of the accelerator, so the dispersion must be measured and controlled frequently. In this paper we present numerical studies of spurious dispersion generation, first dispersion measurements and correction results.

WEPCH021	Generalized Twiss Coefficients Including Transverse Coupling and E-beam Growth	undulator, emittance, CSR, radiation	1966
	F. Ciocci, G. Dattoli ENEA C.R. Frascati, Frascati (Roma) M. Migliorati Rome University La Sapienza, Roma
	We use a generalization of the Twiss coefficients to the fully transverse coupled case. We show that the formalism is particularly useful to treat problems involving the beam optics of electrons propagating in undulators or solenoids. The method allows the treatment in analytical terms, we generalize the method including the effect of spatial charges and higher order multi-polar terms. The method is then applied to a specific example relevant to e-beam emittance dilution in solenoid and exotic undulators.

WEPCH023	Longitudinal Coherent Oscillation Induced in Quasi-isochronous Ring	synchrotron, power-supply, storage-ring, closed-orbit	1972
	Y. Shoji, Y. Hisaoka, T. Matsubara, T. Mitsui NewSUBARU/SPring-8, Laboratory of Advanced Science and Technology for Industry (LASTI), Hyogo
	Noise sources, which excite longitudinal coherent oscillation is discussed. Especially in a quasi-isochronous electron storage ring an identification of the noise sources is important to obtain an extremely short bunch. One possible source is a well-known rf noise in the acceleration field. The other is a magnetic field ripple, which changes a path-length for a revolution. The analytical formula for the longitudinal coherent oscillation is explained. It contains the path-length oscillation, which had never been considered. The third is a beam itself, probably be a coherent radiation loss. The driving term is not symmetric along the energy axis, then the oscillation amplitude depends on the higher order momentum compaction factor.

WEPCH025	COD Correction at the PF Ring by New Orbit Feedback Scheme	feedback, simulation, insertion, insertion-device	1978
	K. Harada, T. Obina KEK, Ibaraki N. Nakamura, H. Sakai, H. Takaki ISSP/SRL, Chiba
	When we correct the global COD (closed orbit distortion), if we use the modified conversion matrix calculated by the eigen vector method with constraint conditions (EVC), the local orbit correction can be simultaneously done to fix the light source point in the insertion device. In the EVC, the local orbit correction is combined to the global orbit correction by the Lagrange's undetermined multiple method. In this paper, we show the machine study results at the PF Ring.

WEPCH032	Orbit Correction System for S-LSR Dispersion-free Mode	proton, closed-orbit, kicker, ion	1993
	H. Souda, S. Fujimoto, M. Ikegami, A. Noda, T. Shirai, M. Tanabe Kyoto ICR, Uji, Kyoto H. Fadil MPI-K, Heidelberg
	An ion storage ring S-LSR has been constructed at ICR, Kyoto Univ. It is a small ring with 22.557m circumference, and has an electron cooler and laser cooling section to achieve crystalline beam. In the commissioning process, closed orbit correction of a 7MeV proton beam has been successfully realized by means of Simplex Method. Responses to the correctors are linear only within narrow limits because of the space-charge effect in the electron cooler. Therefore, the correction must be repetition of small corrections. Under such condition, measured COD has been reduced less than 0.1mm. Orbit correction is necessary for 35keV Mg+ dispersion-free mode* using both bending magnets and electrostatic deflectors. Since electrostatic deflectors have relatively large field errors, it needs a special process to inject the beam into the dispersion-free mode ring. First circulation is under only the magnetic field, then, the electric field will be added little by little applying continuous COD correction. In this way the dispersion gradually diminishes with keeping stable orbit. In this paper we present the correction scheme and the trial to the dispersion-free circulation. *M. Ikegami et al. Phys. Rev. ST-AB, 7, 120101-1 (2004).

WEPCH040	Further Development of Irradiation Field Forming Systems of Industrial Electron Accelerators	target, vacuum, radiation, extraction	2005
	N.G. Tolstun, A.S. Ivanov, V.P. Ovchinnikov, M.P. Svinin NIIEFA, St. Petersburg
	Electron beam irradiation field forming systems where accelerated electron beam is scanned in a constant field of the elongated bending magnets were developed in our institute more than 15 years ago and they have a number of advantages in comparison with traditional ones. Since than they have been applied in two accelerators with energies 300 and 400 keV; version of the similar system with two electromagnets for two-side irradiation of flexible materials – in a number of 750 keV high voltage accelerators ("Electron-10") successfully operating now in several industrial lines. Systems of forming of electron beam irradiation field based on the same principle have been used in several projects, some of them are already put into operation. Electron optic characteristics of such systems and their various modifications as well as aspects of their possible usage are discussed in the paper.

WEPCH041	Analytic Study of Longitudinal Dynamics in Race-track Microtrons	synchrotron, longitudinal-dynamics, injection, microtron	2008
	Yu.A. Kubyshin UPC, Barcelona A.V. Poseryaev, V.I. Shvedunov MSU, Moscow
	Implementation of low energy injection schemes in the race-track microtron (RTM) design requires a better understanding of the longitudinal beam dynamics. Differently to the high energy case a low-energy beam will slip in phase relative to the accelerating structure phase. We generalize the concept of equilibrium or synchronous particle for the case of non-relativistic energies and introduce the notion of transition energy for RTMs. An analytical approach for the description of the synchronous phase slip is developed and explicit, though approximate, formulas which allow to define the equilibrium injection phase and fix the parameters of the accelerator are derived. The approximation can be improved in a systematic way by calculating higher order corrections. The precision of the analytical approach is checked by direct numerical computations using the RTMTrace code and was shown to be quite satisfactory. Explicit examples of injection schemes and fixing of RTM global parameters are presented.

WEPCH053	Peculiarities of Influence of Coherency Processes at Charged Particles Channeling on Particle Beams Characteristics	positron, proton, controls	2041
	V.I. Vysotskii, M.V. Vysotskyy National Taras Shevchenko University of Kyiv, Radiophysical Faculty, Kiev
	In the work the length of reciprocal coherency existence and peculiarities of coherency of different states of channeled particles wave functions are discussed. It was shown that the length of coherent channeling depends on the monochromaticity of initial particle beam as well as on the interaction of channeled particles with thermal oscillations of the crystal lattice. Peculiarities of influence of coherency processes at relativistic and nonrelativistic charged particles channeling on spatial and angular characteristics of particle beam that has passed through a thin crystal are discussed. In was shown, that the influence of different particle states interference within the area of coherent channeling leads to very strong periodic dependence of final beam angular width from the crystal length. This effect allows to control beam parameters (e.g., to form narrower beam, that it was before falling on the crystal). Influence of coherency of particle states in a single channel and several channels on the angular distribution and the possibility of quasicharacteristic short-wave spontaneous and stimulated radiation is also studied.

WEPCH061	SABER Optical Design	positron, linac, SLAC, sextupole	2062
	R.A. Erickson, K.L.F. Bane, P. Emma, Y. Nosochkov SLAC, Menlo Park, California
	SABER, the South Arc Beam Experimental Region, is a proposed new beam line facility designed to replace the Final Focus Test Beam at SLAC. In this paper, we outline the optical design features and beam parameters now envisioned for SABER. A magnetic chicane to compress positron bunches for SABER and a bypass line that could transport electrons or positrons from the two-thirds point of the linac to SABER, bypassing the LCLS systems, are also discussed.

WEPCH068	6-D Beam Dynamics Studies in EMMA FFAG	LEFT, acceleration, dipole, quadrupole	2080
	F. Meot CEA, Gif-sur-Yvette
	Extensive simulations of 6-D transmission simulations in linear, non-scaling FFAGs, based on gutter rapid acceleration, are reported. They concern two different on-going projects: the 20~GeV muon accelerators in the Neutrino Factory (NuFact) with ISS parameters* and a 20~MeV electron model of these machines, EMMA*. http://www.hep.ph.ic.ac.uk/iss/**http://hepunx.rl.ac.uk/uknf/wp1/emodel/

WEPCH073	Asymptotic Analysis of Ultra-relativistic Charge	electromagnetic-fields, radiation, vacuum, controls	2086
	D.A. Burton, J. Gratus, R. Tucker Lancaster University, Lancaster
	A new approach is developed for analysing the dynamic behaviour of distributions of charged particles in an electromagnetic field. Noting the limitations inherent in the Lorentz-Dirac equation for a single point particle, a simple model is proposed for a charged continuum interacting self-consistently with the Maxwell field in vacuo. The model is developed using intrinsic tensor field theory and exploits to the full the symmetry and light-cone structure of Minkowski spacetime. This permits the construction of a regular stress-energy tensor whose vanishing divergence determines a system of non-linear partial differential equations for the velocity and self-fields of accelerated charge. Within this covariant framework a particular perturbation scheme is motivated by an exact class of solutions to this system describing the evolution of a charged fluid under the combined effects of both self and external electromagnetic fields. The scheme yields an asymptotic approximation in terms of inhomogeneous linear equations for the self-consistent Maxwell field, charge current and time-like velocity field of the charged fluid and is defined as an ultra-relativistic configuration.

WEPCH078	Measurement of Wake Effects by Means of Tune Shift in the KEKB Low-Energy Ring	positron, betatron, single-bunch, KEKB	2101
	T. Ieiri, H. Fukuma, Y. Ohnishi, M. Tobiyama KEK, Ibaraki
	The electron cloud produced by the positron beam induces single-bunch and coupled-bunch wakes, in addition to a tune shift. Effects of the dipole wake-field including the electron cloud were tried to measure in the KEKB Low Energy Ring. A test bunch was placed behind a bunch-train of the positron beam, even though a test bunch itself might interact with the remaining electron cloud. We measured a current-dependent tune-shift of a test bunch under constant train-current, while changing the bucket position of a test bunch. The tune shift indicated a strong defocusing field, however, tended to a focusing field when a test bunch approached a train with high train-current. The results are discussed, considering variations of the electron cloud density.

WEPCH097	Beam Dynamics in Compton-ring Gamma Sources	laser, synchrotron, emittance, simulation	2143
	E.V. Bulyak, P. Gladkikh, V. Skomorokhov NSC/KIPT, Kharkov K. Moenig DESY Zeuthen, Zeuthen T. Omori, J. Urakawa KEK, Ibaraki F. Zimmermann CERN, Geneva
	Electron storage rings with a laser cavity are promising intensive sources of polarized hard photons to generate polarized positron beams. The dynamics of electron bunches circulating in a storage ring and interacting with high-power laser pulses is studied both analytically and by simulation. Common features and difference in the bunch behavior interacting with an extremely high power laser pulse (polarized positron source for the ILC project) and a moderate pulse (source for CLIC) are shown. Also considerations on particular lattice designs for both rings are presented.

WEPCH101	Ion Motion in the Adiabatic Focuser	ion, emittance, focusing, plasma	2149
	A. Sessler, E. Henestroza, S. Yu LBNL, Berkeley, California
	The Adiabatic Focuser* works by having a focusing channel whose strength increases with distance down the channel. In this situation electrons of various energies and various transverse oscillation phase all are transversely focused. The concept works with external focusing, but would be very effective in a plasma ion focusing channel where the density of ions is simply increased as one goes down the channel. In the original work (Ref 1) motion of the ions was not included (as it was assumed to be a small effect). Recently, it has been suggested that ion motion in an adiabatic focuser would be significant and, even, preclude operation of the focuser as previously envisioned*. In this paper we numerically study the ion motion in the focuser. The ions clearly influence each other and, most importantly, are influenced by the electric field of the electrons being focused. It is shown that parameters can be selected such that the adiabatic focuser works as well as originally envisioned. P. Chen et al. Phys. Rev. Lett. 64, 1231 (1990).**J. R. Rosenzweig, et al. Phys. Rev. Lett. 95, 195002 (2005).

WEPCH103	Ion Effects in the Electron Damping Ring of the International Linear Collider	ion, damping, emittance, ion-effects	2155
	L. Wang, T.O. Raubenheimer SLAC, Menlo Park, California A. Wolski Liverpool University, Science Faculty, Liverpool
	Ion-induced beam instabilities and tune shifts are critical issues for the electron damping ring of the International Linear Collider (ILC). To avoid conventional ion trapping (multi-turn trapping), a long gap is introduced in the electron beam by omitting a number of successive bunches out of a long train. However, the beam can still suffer from the fast ion instability (FII), driven by ions that last only for a single passage of the electron bunches. Our study shows that the ion effects can be significantly mitigated by using multiple gaps, so that the stored beam consists of a number of relatively short bunch trains. The ion effects in the ILC damping rings are investigated using both analytical and numerical methods.

WEPCH106	Stationary Beam Electron Transport in AIRIX for the TRAJENV Code	space-charge, induction, focusing, target	2161
	O. Mouton CEA, Bruyères-le-Châtel
	In the framework of the AIRIX program, the electron beam propagation between the injector and the X-conversion target is routinely simulated with the 2D TRAJENV code. We describe the physical models implemented in the code for a intense stationary beam. We present both the modeling of applied electromagnetic forces in induction cells and self generated ones. To avoid the cell damage due to target debris generated by the electron beam impact, a thin debris shield has been tested upstream the X-ray converter. Such a thin foil located in the beam pass, is taken into account in TRAJENV. We describe the modeling and the influence of the foil on the beam.

WEPCH107	Contributors to AIRIX Focal Spot Size	target, ion, emittance, simulation	2164
	N. Pichoff, M. Caron, F. Cartier, D.C. Collignon, A. Compant La Fontaine, G. Grandpierre, L.H. Hourdin, M. Mouillet, D.P. Paradis CEA, Bruyères-le-Châtel
	High intensity electron beam focusing is a key issue for the successful development of flash radiography at hydro test facilities. AIRIX is a 2 kA, 19 MeV, 60 ns, single shot linear accelerator that produces X-rays from the interaction between relativistic electrons and a Tantalum solid target (Ta). A simulation tool has been developed to model the pulsed-beam dynamics through the accelerator from the cathode to the target. This simulator has allowed to estimate the contribution to the beam size on the target (focal spot) of beam emittance, pulse energy dispersion, pulse rising and falling fronts and the ion production on the target. The quantified contributions of these phenomena are reviewed here.

WEPCH112	Database Extension for the Beam Dynamics Simulation Tool V-code	quadrupole, simulation, gun, multipole	2176
	W. Ackermann, W.F.O. Müller, B. Steiner, T. Weiland TEMF, Darmstadt J. Enders, H.-D. Gräf, A. Richter TU Darmstadt, Darmstadt
	The beam dynamics simulation tool V-Code has been proved to be very useful in redesigning the injector layout at the superconducting linear accelerator in Darmstadt (S-DALINAC). Modifications in the beam optics are necessary because a new source of polarized electrons should be installed in addition to the existing thermionic gun. The calculations are performed with V-Code which is designed to handle a large amount of individual beam line elements and can therefore be used for extensive accelerator studies. The available database includes all the necessary components like solenoids, quadrupoles and rf cavities, but as a result of their consecutive treatment overlapping external fields are not allowed. Due to geometrical restrictions in the assembly of the new source a space-saving candidate of a quadrupole triplet violates this software-related condition if it is regarded as three distinct quadrupoles. Consequently, a more general beam line element has to be created which treats the lenses as a single unit without interference of their fields to attached cells. The indispensable data base extension together with simulation results and implementation verifications will be presented.

WEPCH115	Numerical Simulation and Optimization of a 3-GHz Chopper/Prebuncher System for the S-DALINAC	impedance, simulation, MAMI, acceleration	2185
	N. Somjit, W.F.O. Müller, T. Weiland TEMF, Darmstadt R. Eichhorn, J. Enders, H.-D. Gräf, C. Heßler, Y. Poltoratska, A. Richter TU Darmstadt, Darmstadt
	A new source of polarized electrons with an energy of 100 keV is presently being developed at the superconducting Darmstadt electron linear accelerator S-DALINAC for future nuclear- and radiation-physics experiments. The pulsed electron beam emitted by the photocathode will be cut to 50 ps by a chopper operated at 3 GHz, and further bunch compression down to 5 ps will be achieved by a two-stage prebuncher section. The chopper-prebuncher system is based on similar devices used at the Mainz Mikrotron (MAMI) where the accelerator frequency is slightly smaller (2.4 GHz). For the chopper, a cylindrical resonator operating at TM110 mode is selected to deflect the electron beam onto an ellipse, i.e., both horizontally and vertically. This is simply achieved by particular slits on both ends of the resonator. The prebunching system consists of two cavities. For increasing the longitudinal capture efficiency, the first cavity will be operated at the fundamental accelerator frequency of the S-DALINAC of 3 GHz, and the second cavity at 6 GHz. The cavities are designed to work at the TM010 mode and TM020 mode for the fundamental and first harmonic, respectively.

WEPCH116	Recent Simulation Results of the Polarized Electron Injector (SPIN) of the S-DALINAC	simulation, gun, quadrupole, MAMI	2188
	B. Steiner, W.F.O. Müller, T. Weiland TEMF, Darmstadt J. Enders, H.-D. Gräf, C. Heßler, G. Iancu, A. Richter, M. Roth TU Darmstadt, Darmstadt
	Recent design and development for a polarized electron source (SPIN) for the recirculating superconducting electron linear accelerator S-DALINAC will be presented. The polarized electron beam will be produced by photoemission from an InAlGaAs/GaAs superlattice cathode and will be accelerated to 100 kV electrostatically. The results of the beam dynamics simulation will be shown in detail. The start phase space of the electron bunch behind the gun has been approximated. The transverse focusing system consists of very short quadrupoles. Further main components of the new injector are a Wien filter, a Mott polarimeter, a chopper-prebuncher system (based on devices used at the Mainz Mikrotron MAMI), and diverse beam diagnostic tools. For the approximation of the start phase space CST MAFIA is used, and for the beam dynamic simulation VCode is used.

WEPCH121	3D Space-charge Calculations for Bunches in the Tracking Code ASTRA	space-charge, ASTRA, DESY, simulation	2203
	G. Pöplau, U. van Rienen Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock K. Floettmann DESY, Hamburg
	Precise and fast 3D space-charge calculations for bunches of charged particles are of growing importance in recent accelerator designs. One of the possible approaches is the particle-mesh method computing the potential of the bunch in the rest frame by means of Poisson's equation. In that, the charge of the particles are distributed on a mesh. Fast methods for solving Poisson's equation are the direct solution applying Fast Fourier Methods (FFT) and a finite difference discretization combined with a multigrid method for solving the resulting linear system of equations. Both approaches have been implemented in the tracking code ASTRA. In this paper the properties of these two algorithms are discussed. Numerical examples will demonstrate the advantages and disadvantages of each method, respectively.

WEPCH124	BDSIM - Beamline Simulation Toolkit Based on Geant4	simulation, quadrupole, CLIC, scattering	2212
	I.V. Agapov, G.A. Blair, J. Carter Royal Holloway, University of London, Surrey O. Dadoun LAL, Orsay
	BDSIM is a code that combines accelerator-style particle tracking with traditional Geant-style tracking based on Runge-Kutta techniques. This approach means that particle beams can be tracked efficiently when inside the beampipe, while also enabling full Geant4 processes when beam-particles interact with beamline apertures. Tracking of the resulting secondary particles is automatic. The code is described, including a new MAD-style interface and new geometry description, and key performance parameters are listed.

WEPCH126	Issues in Modelling of Negative Ion Extraction	ion, plasma, extraction, scattering	2218
	M. Cavenago INFN/LNL, Legnaro, Padova V. Antoni, F. Sattin CNR/RFX, Padova
	In the context of negative ion sources proposed for neutral beam injectors for tokamaks, halo of the extracted beam is typically large (about 10 %) and optimum shape of the multiaperture extraction electrode is a matter of research. Present designs range from an aperture angle of 45 degree (low current, convergent beam) to 90 degrees (flat electrode, high current, large divergence and halo). Two major difficulties of the beam extraction modelling are here discussed. First, the generation processes of negative ion show some shortcomings: volume production seems low; wall production is large, but ions have wrong directions and/or large nonuniformity in current density; elastic scattering of wall generated ions into the extraction direction must compete with mutual neutralization. Second, the plasma sheath charge has to be negative on the extraction hole surface and positive on the nearby wall surface, which enhances beam aberration near hole edge. After discussing limitation of existing codes and model, result from an ad hoc code are discussed. Also 2D equation for the selfconsistent electrostatic field can be written and implemented into a multiphysics general purpose program.

WEPCH127	Analysis of Radiative Effects in the Electron Emission from the Photocathode and in the Acceleration inside the RF Cavity of a Photoinjector using the 3D Numerical Code RETAR	radiation, acceleration, extraction, brightness	2221
	V. Petrillo, C. Maroli Universita' degli Studi di Milano, Milano G. Alberti Università degli Studi di Milano, Milano A. Bacci, A.R. Rossi, L. Serafini INFN-Milano, Milano M. Ferrario INFN/LNF, Frascati (Roma)
	The three-dimensional fully relativistic and self-consistent code RETAR has been developed to model the dynamics of high-brightness electron beams and in particular to assess the importance of the retarded radiative part of the emitted electromagnetic fields in all conditions where the electrons experience strong accelerations. In this analysis we evaluate the radiative energy losses in the electron emission process from the photocathode of an injector, during the successive acceleration of the electron beam in the RF cavity and the focalization due to the magnetic field of the solenoid, taking also into account the e.m. field of the laser illuminating the cathode. The analysis is specifically carried out with parameters of importance in the framework of the SPARC and PLASMONX projects.

WEPCH131	Development of Numerical Code for Self-consistent Wake Field Analysis with Curved Trajectory Electron Bunches	simulation, electromagnetic-fields, radiation, coupling	2230
	H. Kawaguchi Muroran Institute of Technology, Department of Electrical and Electronic Engineering, Muroran K. Fujita Hokkaido University, Sapporo
	Strongly interacting phenomena of electromagnetic radiation fields and ultra-relativistic electron is one of great interests in accelerator science such as in electron beam dynamics at the bunch compressor. The phenomena are described by time domain boundary value problem for the Lienard-Wiechert solutions. Authors develop a time domain boundary element method for self-consistent wake fields analysis of electromagnetic fields and charged particles. To use boundary integral equation for describing the electromagnetic fields, the time domain boundary value problems for the Lienard-Wiechert solution can be naturally formulated and we can simulate the wake fields phenomena with electron beam dynamics. In this paper, beam dynamics of curved trajectory electron bunches inside uniform beam tube are numerically simulated by using 2.5 dimension time domain boundary element technique. Various effects of closed beam tube for ultra-relativistic electron dynamics are considered comparing with the Lienard-Wiechert solutions in free space.

WEPCH132	Design Study of Dedicated Computer System for Wake Field Analysis with Time Domain Boundary Element Method	simulation, BNL, CSR, controls	2233
	K. Fujita, T. Enoto Hokkaido University, Sapporo H. Kawaguchi Muroran Institute of Technology, Department of Electrical and Electronic Engineering, Muroran
	Time domain boundary element method (TDBEM) has advantages of dispersion free calculations and modeling of curved beam trajectories in wake field analysis compared to conventional methods. These advantages give us powerful possibilities for analysis of beam dynamics due to CSR in bunch compressors of next-generation accelerators. On the other hand, the TDBEM also has a serious difficulty of large computational costs. In this paper, a dedicated computer system for wake field analysis with the TDBEM is proposed as one of solutions for high performance computing (HPC) technologies. Recent remarkable progress of LSI hardware design environments such as HDL compiler tools and large scale FPGAs enables us to make up computer hardware systems with very low cost in a short development period. The authors have been working in design studies of the TDBEM dedicated computer system on such LSI design environments. This paper presents a system design and VHDL simulations of a wake field analysis machine based on the TDBEM.

WEPCH137	FAKTOR2: A Code to Simulate the Collective Effects of Electrons and Ions	ion, simulation, LEFT, CLIC	2242
	W. Bruns, D. Schulte, F. Zimmermann CERN, Geneva
	A new code for computing the multiple effects of slowly moving charges is being developed. The basic method is electrostatic particle in cell. The underlying grid is rectangular and locally homogeneous. At regions of interest, e.g., where the beam is, or near material boundaries, the mesh is refined recursively. The motion of the macroparticles is integrated with an adapted timestep. Fast particles are treated with a smaller timestep, and particles in regions of fine grids are also treated with a fine timestep. The position of collision of particles with material boundaries is accurately resolved. Secondary particles are then created according to user-specified yield functions.

WEPCH141	Accelerator Physics Code Web Repository	simulation, CERN, space-charge, site	2254
	F. Zimmermann, R. Basset, E. Benedetto, U. Dorda, M. Giovannozzi, Y. Papaphilippou, T. Pieloni, F. Ruggiero, G. Rumolo, F. Schmidt, E. Todesco CERN, Geneva D.T. Abell Tech-X, Boulder, Colorado R. Bartolini Diamond, Oxfordshire O. Boine-Frankenheim, G. Franchetti, I. Hofmann GSI, Darmstadt Y. Cai, M.T.F. Pivi SLAC, Menlo Park, California Y.H. Chin, K. Ohmi, K. Oide KEK, Ibaraki S.M. Cousineau, V.V. Danilov, J.A. Holmes, A.P. Shishlo ORNL, Oak Ridge, Tennessee L. Farvacque ESRF, Grenoble A. Friedman LLNL, Livermore, California M.A. Furman, D.P. Grote, J. Qiang, G.L. Sabbi, P.A. Seidl, J.-L. Vay LBNL, Berkeley, California D. Kaltchev TRIUMF, Vancouver T.C. Katsouleas USC, Los Angeles, California E.-S. Kim PAL, Pohang, Kyungbuk S. Machida CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon J. Payet CEA, Gif-sur-Yvette T. Sen Fermilab, Batavia, Illinois J. Wei BNL, Upton, Long Island, New York B. Zotter Honorary CERN Staff Member, Grand-Saconnex
	In the framework of the CARE HHH European Network, we have developed a web-based dynamic accelerator-physics code repository. We describe the design, structure and contents of this web repository, illustrate its usage, and discuss our future plans.

WEPCH143	Electron Linac Based e,X-radiation Facility	target, radiation, photon, simulation	2257
	V.I. Nikiforov, A. Dovbnya, N.A. Dovbnya, V.L. Uvarov NSC/KIPT, Kharkov
	In a number of technologies based on high-current electron accelerators bremsstrahlung is generated in the interaction of the beam with the irradiated object. Thus, in addition to the electron radiation, the bremsstahlung may be used for carring out of different technolodgical programs (e,X-facility). A method for the numerical analysis and optimization of the radiation characteristics of such installation is proposed. The accelerator beam track, starting from the electron source and up to output devices is considered as a single multicomponent target consisting of the layers of different materials. The thickness of each layer is measured in the generalized units of the "stopping length". Using the method of simulation based on the PENELOPE/2001 system the characteristics of the mixed e,gamma-radiation field (energy yield of electrons, photons and their ratio) as function of the stopping length for actual or anticipated version of output equipment can be calculated. To illustrate the method, the parameters of the beam path of the NSC KIPT Linacs used as e,X-facilities was analyzed.

WEPCH147	Simulations of Electron Effects in Superconducting Cavities with the VORPAL Code	simulation, plasma, laser, radio-frequency	2269
	C. Nieter, J.R. Cary, P. Messmer, D.S. Smithe, P. Stoltz Tech-X, Boulder, Colorado G.R. Werner CIPS, Boulder, Colorado
	Modeling the complex boundaries of superconducting radio frequency (SRF) accelerating cavities on a Cartesian grid is a challenge for many Finite Difference Time Domain (FDTD) electromagnetic PIC codes. The simulation of such cavities require conformal (curve fitting) boundaries. Modeling the full cavity including couplers and ports is fundamentally a three dimensional problem requiring capability to run in parallel on large numbers of processors. We have recently added conformal boundaries using the method of Zagorodnov* to the plasma simulation code VORPAL. Using this higher order boundary algorithm and the surface physics package TxPhysics, we have begun studies of self-consistent electron effects in SRF cavities. We have modeled the beam excitation of cavity modes and the effects of electron multipacting. Results from these studies will be presented using the new user friendly visualization tool that now ships with VORPAL. *I. A. Zagorodnov et al. “A uniformly stable conformal FDTD-method in Cartesian grids,” International Journal of Numerical Modeling 16, 127 (2003).

WEPCH161	The FFAG R&D and Medical Application Project RACCAM	lattice, proton, acceleration, synchrotron	2308
	F. Meot CEA, Gif-sur-Yvette B. Autin, J. Collot, J.F. Fourrier, E. Froidefond, F. Martinache LPSC, Grenoble J.L. Lancelot, D. Neuveglise SIGMAPHI, Vannes
	The RACCAM project (Recherche en ACCelerateurs et Applications Medicales) has recently obtained fundings, extending over three years (2006-2008), from the French National Research Agency (ANR). RACCAM is a tripartite collaboration, involving (i) the CNRS Laboratory IN2P3/LPSC, (ii) the French magnet industrial SIGMAPHI, and (iii) the nuclear medecine Departement of Grenoble Hospital. The project concerns fixed field alternating gradient accelerator (FFAG) research on the one hand, and on the other hand their application as hadrontherapy and biology research machines. RACCAM's goal is three-fold, (i) participate to the on-going international collaborations in the field of FFAGs and recent concepts of "non-scaling" FFAGs, with frames for instance, the Neutrino Factory (NuFact) and the EMMA project of an electron model of a muon FFAG accelerator, (ii) design, build and experiment a prototype of an FFAG magnet proper to fulfil the requirements of rapid cycling acceleration, (iii) develop the concepts, and show the feasibility, of the application of such FFAG beams to hadrontherapy and to biology research. CEA/DAPNIA and IN2P3/LPSC IN2P3/LPSC Grenoble University Hospital **SIGMAPHI

WEPCH166	Beam Test of Thermionic Cathode X-band RF-gun and Linac for Monochromatic Hard X-ray Source	laser, photon, linac, cathode	2319
	K. Dobashi, A. Fukasawa, M. D. Meng, T. Natsui, F. Sakamoto, M. Uesaka, T. Yamamoto UTNL, Ibaraki M. Akemoto, H. Hayano, T. Higo, J. Urakawa KEK, Ibaraki
	A compact hard X-ray source based on laser-electron collision is proposed. The X-band linac is introduced to realize a very compact system. 2MeV electron beam with average current 2μampere at 10 pps, 200 ns of RF pulse is generated by a thermionic cathode X-band RF-gun. Beam acceleration and X-ray generation experiment by the X-band beam line are under way.

WEPCH172	Electron Beam Pulse Processing toward the Intensity Modified Radiation Therapy (IMRT)	radiation, laser, cathode, gun	2334
	T. Kondoh, S. Tagawa, J. Yang, Y. Yoshida ISIR, Osaka
	Radiation therapy attracts attention as one of the cancer therapies nowadays. Toward the next generation of the intensity modified radiation therapy (IMRT), the processing of electron beam pulse is studied using a photo cathode RF gun linac. Accelerated electron pulses will be converted to x-ray pulses by a metal target bremsstrahlung method or by a laser inverse Compton scattering method. Recently, the radiation therapy of cancer is developing to un-uniform irradiation as IMRT. A photo cathode RF gun is able to generate a low emittance electron beam pulse using a laser light pulse. We thought that a photo cathode RF gun can generate intensity and shape modified electron beam by processing of incident laser light. Because of a low emittance, an electron pulse is able to accelerate keeping shape. Electron beam processing by photo masks in incident optical system and generated beams are reported here. Images on photo masks were transported to a cathode surface by optical relay imaging. Beams were monitored by Desmarquest (Cr:Al2O3) luminescence. Spatially separation of a spot to a spot is about 0.3mm. Modified electron beam has fine spatial resolution.

WEPCH175	Design of 12 MEV RTM for Multiple Applications	linac, acceleration, radiation, microtron	2340
	A.V. Poseryaev, V.I. Shvedunov MSU, Moscow M.F. Ballester, Yu.A. Kubyshin UPC, Barcelona
	Design of a compact 12 MeV race-track microtron (RTM) is described. The results of operating wavelength choice, accelerating structure and end magnets optimization and beam dynamics simulation are represented. Use of a C-band linac and rare earth permanent magnet end magnets permit to design RTM, which is more compact and more effective as compared with the same energy circular microtron or linac. Electron beam with energy 4-12 MeV in 2 MeV step can be extracted from RTM. The estimated pulsed RF power required for feeding the linac is about 800 kW, total mass of accelerator is less than 40 kg and its dimensions are about 500x200x110 mm3.

WEPCH177	Conception of Medical Isotope Production at Electron Accelerator	target, radiation, simulation, isotope-production	2343
	V.L. Uvarov, N.P. Dikiy, A. Dovbnya, V.I. Nikiforov NSC/KIPT, Kharkov
	A photonuclear method with the use of high-energy bremsstrahlung (Eg>8 MeV) of high intensity (>= 10⁰⁴ W/cm2) provides a possibility of the ecologically safe production of a number of isotopes for nuclear medicine. The conditions of generation of the radiation field having such characteristics as well as the features of photonuclear production of W-181,Pd-103, Cu-67 and other radionuclides are considered in the report. At the initial stage the study of the isotope production is performed by means of the computer simulation in a simplified 2D geometry of the Linac output devices. The code on the base of the PENELOPE/2001 program system supplemented with the data on the excitation functions of the corresponding reactions was developed. The dependences of the isotope yield (gross and specific activity) on the electron energy (30…45 MeV), as well as, the data on absorbed energy of radiation in the targets of natural composition are represented. The experimental results confirm the data of modelling. Main trends of realization of the photonuclear method for isotope production and the necessary conditions of the increase of its yield are analysed.

WEPCH178	Simulation Study of Compact Hard X-ray Source via Laser Compton Scattering	linac, simulation, focusing, laser	2346
	R. Kuroda, M.K. Koike, H. Ogawa, N. Sei, H. Toyokawa, K. Y. Yamada, M.Y. Yasumoto AIST, Tsukuba, Ibaraki N. Nakajyo, F. Sakai, T. Yanagida SHI, Tokyo
	The compact hard X-ray source via laser Compton scattering between high intensity electron beam and high power laser beam was developed at FESTA (The Femtosecond Technology Research Association) project in collaboration between AIST and SHI. According to completion of the project in March 2005, the compact hard X-ray source is being transferred from FESTA to AIST to upgrade and to apply the system to biological and medical uses. Our system consists of a laser-driven photocathode rf gun, two 1.5m-long S-band accelerator structures and a high power Ti:Sa Laser system. This system can generate a hard X-ray pulse which has variable energy of 12 keV – 33 keV with narrow bandwidth by changing electron energy and collision angle. Maximum X-ray photon yield at FESTA was accomplished about 10⁷photons/s (@10Hz, MAX 33keV) in case of 165 degree collision angle. In the next phase, we are planning to make the total system much compact using X-band or C-band accelerator structures with permanent magnets. We have carried out the numerical simulations to investigate the possibility of these compact systems. In this conference, we will talk about results of the simulations and future plans.

WEPCH182	Design of 9.4 GHz 950 keV X-band Linac for Nondestructive Testing	linac, gun, target, KEK	2358
	T. Yamamoto, T. Natsui, M. Uesaka UTNL, Ibaraki M. Akemoto, S. Fukuda, T. Higo, M. Yoshida KEK, Ibaraki K. Dobashi The University of Tokyo, Nuclear Professional School, Ibaraki-ken E. Tanabe AET Japan, Inc., Kawasaki-City
	Mobile "suit-case-sized" x-band (9.4GHz) 950 keV linac is designed for applications of nondestructive testing (NDT). Conventional device for the purpose is the S-band linac, but its drawback is a rather large device-size, large electron beam spot size of about 3 mm and lack of spatial resolution. We aim to realize the smaller spot size about 500 micro-m by a low emittance beam. The proposed system consists of the 9.4 GHz magnetron, modulator, thermionic RF electron gun and 9.4 GHz x-band linac and metal target for x-ray generation. The energy at the gun is 20 keV, and the final energy becomes 950 keV. Now, we are designing the linac structure of the pai/2 mode and analyzing the electromagnetic field (EMF) by SUPERFISH. At this time, we finish analyzing EMF of regular cavity cells and we are analyzing EMF of total accelerating tube. We have finished the detailed RF design. Further, we are also performing the design of the pai mode and going to discuss the advantages and drawbacks between them. Construction of the RF supplying system is underway. The detailed design parameters and updated status of the construction are presented at the spot.

WEPCH183	Enhancement of Mechanical Properties of High Chromium Steel by Nitrogen Ion Implantation	ion, ion-source, target, controls	2361
	B.S. Kim, S.-Y. Lee Hankuk Aviation University, KyungKi-Do K. R. Kim, J.S. Lee KAERI, Daejon
	This article reports the study of mechanical properties of high chromium steel after N-ion implantation. The samples are implanted with 120keV N-ion at doses ranging from 1x10¹⁷ions/square cm to 4x10¹⁸ions/square cm. Mechanical properties of implanted samples are compared with those of Cr-plated samples. The compositions of the N-ion implanted layer were measured by Auger electrons spectroscopy(AES). Their mechanical properties as a function of N-ion doses were characterized by nano-indentation, sliding and impact wear tests. The results reveal that the hardness and mechanical properties of ion implanted samples were found to depend strongly on the ion doses. The hardness of the N-ion implanted sample with 2x1018ions/? was measured to be approximately 9 GPa, which is approximately 2.3 times higher than that of un-implanted sample (H=3.8 GPa). Also wear properties of N-ion implanted samples with 2x1018ions/? were largely improved ;compared to the Cr-plated samples, the width of wear track and friction coefficient developed on the N-ion implanted samples are about 60% and 40% smaller, respectively.

WEPCH187	A Compact 5 MeV, S-band, Electron Linac Based X-ray Tomography System	linac, simulation, radiation, collimation	2370
	L. Auditore, L. Auditore, R.C. Barnà, D. De Pasquale, D. Loria, A. Trifirò, M. Trimarchi INFN & Messina University, S. Agata, Messina U. Emanuele, A. Italiano INFN - Gruppo Messina, S. Agata, Messina
	The availability of commercial X-ray tubes made of radiography and tomography two of the most used non-destructive testing techniques both in industrial and cultural heritage fields. Nevertheless, the inspection of heavy materials or thick objects requires X-ray energies larger than the maximum energy provided by commercial X-ray tubes (600 kV). For this reason, and owing to the long experience of the INFN-Gruppo Collegato di Messina in designing and assembling low energy electron linacs, at the Dipartimento di Fisica, Universita di Messina, a 5 MeV electron linac based X-ray tomographic system has been developed. The X-ray source, properly designed by means of the MCNP-4C2 code, provides a 16 cm diameter X-ray spot at the sample position and a beam opening angle of about 3.6 degree. The image acquisition system consists of a CCD camera (Alta Apogee E1, 768x512 pixel) and a GOS scintillating screen. Preliminary radiographies and tomographies showing the high quality performances of the tomographic system have been acquired. Finally, the compactness of the linac, is one of the advantages of this system that could be used for in situ inspections when huge structures have to be tested

WEPCH188	Compact Picosecond Pulse Radiolysis System Using Photo-cathode RF Gun	laser, injection, emittance, gun	2373
	M. Washio, Y. Hama, Y. Kamiya, M. Kawaguchi, R. Moriyama, H. Nagai, K. Sakaue RISE, Tokyo H. Hayano, J. Urakawa KEK, Ibaraki S. Kashiwagi ISIR, Osaka R. Kuroda AIST, Tsukuba, Ibaraki K.U. Ushida RIKEN, Saitama
	A very compact picosecond pulse radiolysis system has been installed and operated at Waseda University. The system is composed of a laser photo-cathode RF gun as the pump source and stable Nd:YLF laser as the white light source to probe the reaction in the picosecond region. The white light generation is performed by the non-linear effect of intense laser light with the wavelength of 1047 nm into the water cell. The experimental results with the time resolution of 18 ps by examining the time profile of hydrated electron have been obtained. The system configuration will be also presented at the conference.

WEPCH192	Compact Electron Linear Accelerator RELUS-5 for Radiation Technology Application	power-supply, vacuum, controls, feedback	2385
	D.A. Zavadtsev, A.I. Fadin, A.A. Krasnov, N.P. Sobenin MEPhI, Moscow A.A. Zavadtsev Introscan, Moscow
	The electron linear accelerator for radiation technology application is designed to meet the following main requirements: 3-5 MeV energy, 3-6 microsecond pulse width, and 1 kW average beam power. The accelerating system is a 0.5 m long S-band standing wave on-axis coupled biperiodic structure. A 35-40 kV electron gun with spherical cathode is used as the injector. The RF generator is a 2.5 MW peak power 4 kW average power magnetron. The generated frequency is stabilized by a high Q-factor accelerating system connected into feed-back of the magnetron. The magnetron is fed by a compact 45-55 kV IGBT based modulator. The accelerator is controlled through a PLC-based control system.

WEPCH194	Complex for X-ray Inspection of Large Containers	radiation, shielding, target, controls	2388
	V.M. Pirozhenko, V.M. Belugin, V.V. Elyan, A.V. Mischenko, N.E. Rozanov, B.S. Sychev, V.V. Vetrov MRTI RAS, Moscow Yu.Ya. Kokorovets, V.D. Ryzhikov, N.A. Shumeiko, S.Ya. Yatsenko Communar, Kharkov A.N. Korolev, K.G. Simonov ISTOK, Moscow Region
	The X-ray inspection complex is intended for non-intrusive inspection of large containers in the seaport. The complex has been developed, manufactured, and tested. To provide two projections of irradiated container and ensure reliable inspection, the complex includes two sets each containing self-shielded X-ray source and L-shaped detector array. The X-ray source includes electron linear accelerator with 7.3 MeV energy, conversion target, local radiation shielding, and alignment means. The accelerator uses standing wave bi-periodic structure fed by magnetron generator with 2.8 GHz frequency. It provides intensive electron beam without application of external magnetic field for the beam focusing. This feature makes it possible to use massive local radiation shielding made from iron. The radiation shielding provides large attenuation of scattered X-rays and ensures the radiation safety for personnel as well as high sensitivity of detecting system and good penetrability of the complex.

WEPLS021	The PLASMONX Project for Advanced Beam Physics Experiments	laser, photon, vacuum, emittance	2439
	L. Serafini, A. Bacci, R. Bonifacio, M. Cola, C. Maroli, V. Petrillo, N. Piovella, R. Pozzoli, M. Rome, A.R. Rossi, L. Volpe INFN-Milano, Milano D. Alesini, M. Bellaveglia, S. Bertolucci, R. Boni, M. Boscolo, M. Castellano, A. Clozza, G. Di Pirro, A. Drago, A. Esposito, M. Ferrario, L. Ficcadenti, D. Filippetto, V. Fusco, A. Gallo, G. Gatti, A. Ghigo, M. Incurvati, C. Ligi, F. Marcellini, M. Migliorati, A. Mostacci, L. Palumbo, L. Pellegrino, M.A. Preger, R. Ricci, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stecchi, A. Stella, F. Tazzioli, C. Vaccarezza, M. Vescovi, C. Vicario INFN/LNF, Frascati (Roma) F. Alessandria, F. Broggi, C. De Martinis, D. Giove, M. Mauri INFN/LASA, Segrate (MI) W. Baldeschi, A. Barbini, M. Galimberti, A. Giulietti, A. Gizzi, P. Koester, L. Labate, S. Laville, A. Rossi, P. Tomassini CNR/IPP, Pisa U. Bottigli, B. Golosio, P.N. Oliva, A. Poggiu, S. Stumbo INFN-Cagliari, Monserrato (Cagliari) C.A. Cecchetti, D. Giulietti UNIPI, Pisa D. Levi, M. Mattioli, G. Medici, D. Pelliccia, M. Petrarca Università di Roma I La Sapienza, Roma P. Musumeci INFN-Roma, Roma
	The Project PLASMONX is well progressing into its design phase and has entered as well its second phase of procurements for main components. The project foresees the installation at LNF of a Ti:Sa laser system (peak power > 170 TW), synchronized to the high brightness electron beam produced by the SPARC photo-injector. The advancement of the procurement of such a laser system is reported, as well as the construction plans of a new building at LNF to host a dedicated laboratory for high intensity photon beam experiments (High Intensity Laser Laboratory). Several experiments are foreseen using this complex facility, mainly in the high gradient plasma acceleration field and in the field of mono-chromatic ultra-fast X-ray pulse generation via Thomson back-scattering. We present an innovative scheme of external injection of the SPARC beam into laser wake-field driven plasma waves. Detailed numerical simulations have been carried out to study the generation of short electron bunches, to be injected into plasma waves driven with adiabatically variable density in order to compress the bunch at injection and further accelerate it by preserving a small energy spread and good beam quality.

WEPLS022	ILC Beam Energy Measurement based on Synchrotron Radiation from a Magnetic Spectrometer	photon, radiation, synchrotron, synchrotron-radiation	2442
	E. Syresin, B.Zh. Zalikhanov JINR, Dubna, Moscow Region K.H. Hiller, H.J. Schriber DESY Zeuthen, Zeuthen R.S. Makarov MSU, Moscow
	The magnetic spectrometer with a relative energy resolution of 5·10^-5 was proposed for ILC beam energy measurements. The beam energy measurement is based on precise definition of the beam position at a resolution of 100 nm and B-field integral at an accuracy of 2E-5. A complementary method of the beam energy measurement is proposed at registration of synchrotron radiation (SR) from the energy spectrometer dipole magnets. The measurements of both edge horizontal positions for SR fan on a distance of 50-70 m downstream of the spectrometer magnets permit to determine the beam energy with required resolution. The main principles of the beam energy measurements based on SR, the numerical simulations of SR performed by the GEANT code and proposal of SR monitors with submicron resolution are discussed.

WEPLS028	Improvement of Electron Generation from a Laser Plasma Cathode through Modified Preplasma Conditions Using an Artificial Prepulse	laser, plasma, cathode, acceleration	2448
	K. Kinoshita, T. Hosokai, K. Kobayashi, A. Maekawa, T. Ohkubo, T. Tsujii, M. Uesaka UTNL, Ibaraki A. Yamazaki KURRI, Osaka A.G. Zhidkov NIRS, Chiba-shi
	We have been studying the effects of laser prepulses, plasma cavity formation, wave breaking processes in the laser plasma acceleration. It is important to control the preplasma conditions, so as to stabilize the laser plasma acceleration. The modification of the conditions of the laser plasma interaction through an artificial prepulse, magnetic fields, and/or gas density modulation will affect on the characteristics of accelerated electron beams. As the first step, we carry out experiments with an artificial prepulse. If a shockwave driven by the artificial prepulse matches the main pulse foccal position, localized wave breaking may occur effectively, and consequent electron generation will be enhanced. We use a pulse with 10% energy of the main pulse and 300 ps duration to be focused on the interaction point of the gas jet, to change the plasma distribution there. Using the single-shot diagnosis, we investigate the mechanism and technique to improve the properties of electron beams. We observed a strong correlation between the generation of monoenergetic electrons and optical guiding of the main pulse, during the interaction of 11 TW 37 fs laser pulse and He gas jet.

WEPLS029	Monoenergetic 200fs (FWHM) Electron Bunch Measurement from the Laser Plasma Cathode	radiation, laser, plasma, cathode	2451
	A. Maekawa, T. Hosokai, K. Kinoshita, K. Kobayashi, T. Ohkubo, T. Tsujii, M. Uesaka UTNL, Ibaraki Y. Kondo, Y. Shibata Tohoku University, Sendai T. Takahashi, A. Yamazaki KURRI, Osaka A.G. Zhidkov NIRS, Chiba-shi
	A laser plasma accelerator is the most promising approach to compact accelerators that can generate femtosecond electron bunches. It is expected that the electron bunch duration less than 100fs can be achieved owing to the high frequency of plasma waves. Since the time-resolution of the fastest streak camera is only 200fs, we have to use the coherent transition radiation (CTR) measurement or E/O (electro-optical) method. We plan to perform a single-shot measurement by getting the whole CTR spectrum by a IR polychromator in near future. As the first step forward it, we used a IR bolometer with different filters and obtained the average spectrum. We can generate monoenergetic electron bunches in the condition of laser intensity 3x1019W/cm2 and electron density 6x1019cm-3. The charge is estimated to be about 10pC using ICT (Integrated Current Transformer). The electron bunch accelerated by plasma waves penetrates 300um Ti-foil, and transition radiation is emitted. We measure CTR spectrum using a bolometer. Spectrum distribution of CTR depends on the electron bunch distribution, therefore we can evaluate the bunch duration from it. In the experiment, bunch duration can be estimated.

WEPLS039	Developments on a Diamond-based Cylindrical Dielectric Accelerating Structure	DIAMOND, impedance, vacuum, simulation	2460
	A. Kanareykin, C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio M.E. Conde, W. Gai, J.G. Power ANL, Argonne, Illinois P. Schoessow Tech-X, Boulder, Colorado
	Developments on a high gradient diamond-based cylindrical dielectric loaded accelerator (DLA) is presented. A diamond-loaded DLA can potentially sustain accelerating gradients far in excess of the limits experimentally observed for conventional metallic accelerating structures. The electrical and mechanical properties of diamond make it an ideal candidate material for use in dielectric accelerators: high RF breakdown level, extremely low dielectric losses and the highest available thermoconductive coefficient. We used the hot-filament Chemical Vapor Deposition (CVD) process to produce high quality 5-10 cm long cylindrical diamond layers. Our collaboration has also been developing a new method of CVD diamond surface preparation that reduces the secondary electron emission coefficient below unity. Special attention was paid to the numerical optimization of the coupling section, where the surface magnetic and electric fields were minimized relative to the accelerating gradient and within known metal surface breakdown limits.

WEPLS040	Progress towards an Experimental Test of an Active Microwave Medium Based Accelerator	laser, resonance, controls, acceleration	2463
	A. Kanareykin Euclid TechLabs, LLC, Solon, Ohio P. Schoessow Tech-X, Boulder, Colorado L. Schächter Technion, Haifa
	We have been working on an experimental test of the PASER concept, where an active medium is used to provide the energy for accelerating charged particles. Initial theoretical work in this area focused on acceleration at optical frequencies; however we have identified a candidate active material operating in the X-band: a solution of fullerene (C60) in a nematic liquid crystal has been found to exhibit a maser transition* in this frequency range. The ability to employ a microwave frequency material simplifies the construction of test structures and allows beam experiments to be performed with relatively large beam emittances. We will report results on synthesis and testing of the active material using EPR spectroscopy, design and numerical simulations of bench test structures and plans for future beam experiments. *A. Blank et al. IEEE Trans. Microwave Theory and Techniques 46 (2137) 1998.

WEPLS044	Design of a Superconducting Cavity for a SRF Injector	emittance, gun, laser, cathode	2472
	D. Janssen FZR, Dresden V. Volkov BINP SB RAS, Novosibirsk
	In a collaboration between BESSY, DESY, FZR, MBI and BINP a 3-1/2 cell superconducting RF electron gun is under development at the FZ - Rossendorf. The status of the project and the progress obtained in the last year is reported on this conference. The motivation for the design of a new gun cavity, presented in this paper, is the new FEL project at BESSY. This FEL is designed for a bunch charge of 2.5 nC and the transverse emittance should be comparable with that of the current SRF gun project. In order to compensate the high bunch charge a high electric field on the cavity axis is necessary. In the present paper we will present the design of a 1-1/2 cell cavity for a superconducting RF gun. The active length of the cavity (without beam tube) is 14.4 cm. For the magnetic peak field the conservative value of 130 mT is assumed. The obtained particle energy is 6.6 MeV, corresponding to an accelerating field strength of 45.6 MV/m . In the TESLA cavity the same magnetic peak field is connected with an accelerating field strength of approximately 31 MV/m. Tracking calculation of electron bunches are in progress and will be also reported.

WEPLS045	Study on Low-energy Positron Polarimetry	positron, target, scattering, photon	2475
	A. Schaelicke, K. Laihem, S. Riemann, A. Ushakov DESY Zeuthen, Zeuthen R. Dollan, Th. Lohse Humboldt University Berlin, Institut für Physik, Berlin
	For the design of the International Linear Collider (ILC) a polarised positron source based on a helical undulator system has been proposed. In order to optimise the positron beam, i.e., to ensure high intensity as well as high degree of polarisation, a measurement of the polarisation close to the positron creation point is envisaged. In this contribution methods to determine the positron polarisation at low energies are investigated. These studies are based on simulations with an extended version of Geant4, which allows the tracking of polarised particles taking into account the spin effects.

WEPLS046	Radiation Levels and Activation at the ILC Positron Source	positron, target, undulator, photon	2478
	A. Ushakov, S. Riemann DESY Zeuthen, Zeuthen Eckhard. Elsen, K. Floettmann DESY, Hamburg K.N. Sanosyan CANDLE, Yerevan
	An undulator-based positron source is recommended as baseline design for the International Linear Collider (ILC). Photons generated by electrons passing an undulator hit a rotating target and create electron-positron pairs. The positrons are captured and accelerated. An advantage of this source is the significantly lower radiation level in comparison to a conventional positron source which uses the electron beam directly to produce electron-positron pairs. The fluxes of neutrons and photons have been calculated with the particle transport code FLUKA. The activation of the positron source components has been estimated depending on the parameters of the source. The results for undulator-based and conventional positron sources are compared and presented.

WEPLS050	Experiments with Electron Cloud and Sources	plasma, ion, laser, injection	2490
	M. Cavenago INFN/LNL, Legnaro, Padova G. Bettega, F. Cavaliere, D. Ghezzi, A. Illiberi, R. Pozzoli, M. Rome INFN-Milano, Milano
	The Penning-Malmberg trap ELTRAP installed at University of Milano can provide electron clouds of several sizes for study of non-linear physics: length ranges from 0.15 to 1 m, while diameter is varied between 25 mm and 70 mm by changing the electron source: filament or planar spiral. Vortices develop both in trapped and flowing electron beams. Slow instabilities, due to the accumulation of ions inside the trap are observed and cured by clearing fields. Results as a function of plasma size are described. Plan to install a third laser modulated electron source and additional diagnostic are also summarized.

WEPLS052	High QE Photocathode at FLASH	cathode, gun, laser, vacuum	2496
	D. Sertore, P. Michelato, L. Monaco, C. Pagani INFN/LASA, Segrate (MI) J.H. Han, S. Schreiber DESY, Hamburg
	The RF gun-based photoinjector of the VUV-FEL/TTF at DESY continues to use high quantum efficiency (QE) photocathodes produced at LASA, Milano. To study the photocathode behavior during beam operation, an online QE monitoring tool has been installed. In this paper, we present the hardware and software setup for the online QE measurement and the results so far obtained. The measured QEs are usually higher than at TTF phase 1. We compare the QE values taken in the RF gun with data measured just after production with a continuous UV light source.

WEPLS054	Higher-order Effect Compensation in Magnetic Compressor for < 50 fs Electron Bunch Generation	linac, gun, simulation, quadrupole	2502
	K. Kan, T. Kondoh, J. Yang, Y. Yoshida ISIR, Osaka
	An ultrashort electron bunch is essential for pulse radiolysis, which is a pump-probe measurement based on an ultrashort electron beam and an ultrashort light. In Osaka University, a laser photocathode electron linear accelerator with a magnetic compressor has been constructed for the femtosecond electron bunch generation. An electron beam with bunch length of 98 fs was successfully generated and used in pulse radiolysis. However, an electron beam with bunch length of < 50 fs is required for development of pulse radiolysis with time resolution of 100 fs. To generate such a short bunch, higher order disadvantage effects, which are caused by the fringing fields of the magnets in the compressor, should be compensated. In this paper, a compensation technique of higher-order effects was proposed by using a nonlinear energy modulation in the bunch produced in the linear accelerator by re-phasing the linac away from the zero-crossing of the rf (i.e., away from the linear slope). In the simulation, we compressed the electron bunch into 48 fs at bunch charge of 0.1 nC.

WEPLS055	Development of Double-decker Electron Beam Accelerator for Femto/attosecond Pulse Radiolysis	gun, linac, laser, emittance	2505
	Y.K. Kuroda, T. Kondoh, J. Yang, Y. Yoshida ISIR, Osaka
	The study of electron-induced reactions in femto/attosecond time region is very important for the next electron beam nanofabrication. Pulse radiolysis with time resolution of sub-picosecond, as a powerful method to study such reactions in materials, has been developed by using radio-frequency electron accelerators and ultrashort lasers. In Osaka University, a new concept of double-decker electron beam accelerator is proposed for opening next pulse radiolysis on femto/attosecond time scale. The double electron beams with time delay of 1.4ns (350ps x 4) and bunch charge of 0.5-0.6 nC were generated in a photocathode electron accelerator by injecting two laser pulses into the photocathode. The beam energy of the two beams was 31.7MeV. The transverse normalized emittance was 3~6 mm-mrad for both the beams. The front of them is converted to Cherenkov light and used as a probe light source, and the back is used as a pump source. Both electron pulses are generated by one accelerator, resulting in no time jitter between the pump electron bunch and the probe laser pulse.

WEPLS057	Equivalent Velocity Spectroscopy Based on Femtosecond Electron Beam Accelerator	laser, injection, gun, linac	2511
	S. Takemoto, T. Kondoh, J. Yang, Y. Yoshida ISIR, Osaka
	A new femtosecond pulse radiolysis system, which is called as "Equivalent Velocity Spectroscopy (EVS)" based on a photocathode rf linear accelerator and a femtosecond laser, is developed in ISIR for the study of primly process and ultrafast electron-induced reactions for the nanofabrication. In order to achieve a high time resolution on femtosecond scale, a femtosecond electron beam bunch produced by a photocathode accelerator and a synchronized femtosecond laser were used. The electron bunch and laser pulse were injected with an angle determined by the refractive index of the sample. The electron bunch was also rotated with a same angle, resulting in the time resolution degradation due to the velocity difference between light and the electron in the sample is thus avoided. A jitter compensation technique with a femtosecond streak camera was used to reduce the time jitter between the electron bunch and laser pulse. Moreover, in EVS, a technique of double laser pulse injection was used to improve the signal to noise ratio due to the fluctuation of the laser intensity during the measurement.

WEPLS058	Femtosecond Single-bunch Electron Linear Accelerator Based on a Photocathode RF Gun	gun, linac, laser, emittance	2514
	J. Yang, K. Kan, T. Kondoh, A. Yoshida, Y. Yoshida ISIR, Osaka
	A femtosecond single-bunch electron linear accelerator based on a photocathode rf gun was developed in Osaka University for the study of radiation-induced ultrafast physical and chemical reactions. A 32 MeV single electron bunch with a bunch length of 98 fs in rms was generated successfully in the linear accelerator with a magnet bunch compressor. The dependences of the bunch length and the transverse emittance on the bunch charge were investigated experimentally and theoretically. The higher-order effects in the magnetic field were studied and compensated successfully by using a nonlinear energy-phase correlation in the bunch produced in the linear accelerator. By using the femtosecond electron bunch, an equivalent velocity spectroscopy with a synchronized femtosecond laser, as a new method with femtosecond time-resolution, was developed for study of the ultrafast reactions or phenomena on the femtosecond time scale.

WEPLS063	Laser Driven Linear Collider	laser, radiation, acceleration, collider	2523
	A.A. Mikhailichenko Cornell University, Department of Physics, Ithaca, New York
	We represent the details of scheme allowing long term acceleration with >10GeV/m. The basis of the scheme is a fast sweeping device for laser bunch. After sweeping the laser bunch has a slope with respect to the direction of propagation. So the every cell of accelerating structure becomes illuminated locally only for the moment, when the particle is there. Self consistent parameters allow considering this type of collider as a candidate for post-ILC era.

WEPLS068	The IASA Magnetic Field Mapping (MFM) Project	controls, resonance, dipole, TESLA	2538
	E.P. Pournaras, A. Karabarbounis, C.N. Papanicolas, E. Stiliaris IASA, Athens
	The design and development of an automatic magnetic field mapping device as supporting equipment for the 10 MeV CW-Linac and its transport system at the Institute of Accelerating Systems and Applications (IASA) is presented. The MFM project aims to totally automate the operation of mapping room temperature magnetic field sources, reconstruct the 3D-field shape and reveal nonlinearities in the fridge field regions. The positioning system covers an area of 50x50 cm2 with an accuracy of less than 20 ?m in both axes; magnetic field measurements, mainly based on a Hall probe, can reach in precision the 1x 10^-4 value. Several software tools for the visualization of the measured fields and for a direct comparison with theoretical estimates are also presented.

WEPLS139	Operational Status of Klystron-modulator System for PAL 2.5-GeV Electron Linac	klystron, linac, SLAC, feedback	2703
	S.S. Park, J. Choi, J.Y. Huang, S.H. Kim, S.-C. Kim PAL, Pohang, Kyungbuk
	The klystron-modulator(K&M) system of the Pohang Accelerator Laboratory (PAL) generates high power microwaves for the acceleration of 2.5 GeV electron beams. There are 12 modules of K&M system to accelerate electron beams up to 2.5 GeV nominal beam energy. One module of the K&M system consists of the 200 MW modulator and an 80 MW S-band (2856 MHZ) klystron tube. The total accumulated high-voltage run-time of the oldest unit among the 12 K&M systems has reached nearly 88,000 hours as of December 2005. The overall system availability is well over 95%. In this paper, we review the overall system performance of the high-power K&M system and the operational status of the klystrons and thyratron lifetimes, and the overall system's availability will be analyzed for the period of 1994 to December 2005.

THXPA03	Laser Systems and Accelerators	laser, FEL, undulator, gun	2728
	H. Schlarb DESY, Hamburg
	The presentation will cover the use of laser systems in accelerators. Topics covered will be the use of lasers for the production of electron beam from photocathodes, timing and diagnostics, laser heater systems to control space charge effects, as seed systems. Challenges in terms of stability, pulse shaping, power and pulse lengths, wavelength range and tuning will be covered for the various aspects.
	Transparencies

THYPA01	Overview of FEL Injectors	emittance, brightness, gun, laser	2733
	M. Ferrario INFN/LNF, Frascati (Roma)
	Future light sources based on high gain free electron lasers, require the production, acceleration and transport up to the undulator entrance of high brightness (low emittance, high peak current) electron bunches. Wake fields effects in accelerating sections and in magnetic bunch compressors typically contribute to emittance degradation, hence the photo-injector design and its operation is the leading edge for high quality beam production and for the success of the future light sources. RF guns, photo-cathode materials, laser pulse shaping and synchronization systems are evolving towards a mature technology to produce high quality and stable beams. Nevertheless reduction of thermal emittance, damping of emittance oscillations and bunch compression are still the main issues and challenges for injector designs. With the advent of Energy Recovery Linacs, superconducting RF guns have been also considered in many new projects as a possible electron source operating in CW mode. An overview of recent advancements and future perspectives in FEL injectors will be illustrated in this talk, including a comparison of merits and issues of RF compression versus magnetic compression techniques.
	Transparencies

THOPA01	Formation of Electron Bunches for Harmonic Cascade X-ray Free Electron Lasers	linac, CSR, laser, radiation	2738
	M. Cornacchia, S. Di Mitri, G. Penco ELETTRA, Basovizza, Trieste A. Zholents LBNL, Berkeley, California
	A relatively long electron bunch is required for an operation of harmonic cascade free electron lasers (FELs). This is because they repeatedly employ a principle when the radiation produced in one cascade by one group of electrons proceeds ahead and interacts with other electrons from the same electron bunch in the next cascade. An optical laser is used to seed the radiation in the first cascade. Understandably the length of the electron bunch in this situation must accommodate the length of the x-ray pulse multiplied by a number of cascades plus a time jitter between the arrival time of the electron bunch and a seed laser pulse. Thus a variation of the peak current along the electron bunch as well as slice energy spread and emittance may affect the performance of the FEL. In this paper we analyze all possible sources affecting the distributions and interplay between them and show how desirable distributions can be produced. Results are illustrated with simulations using particle tracking codes.
	Transparencies

THOPA02	Status of the SCSS Test Accelerator and XFEL Project in Japan	emittance, undulator, cathode, radiation	2741
	T. Shintake RIKEN Spring-8 Harima, Hyogo
	Construction of the SCSS* 250 MeV test accelerator was completed in October 2005, and the beam commissioning was started in November 2005. The first light at visible wavelength, which is the spontaneous radiation from undulator, was observed right after machine commissioning. We expect the first SASE beam around 60 nm in 2006. The purpose of the test accelerator is to assemble all hardware components in a real machine, and check their performance, reliability and stability. It is also very important to build all control software and link to the main frame to see system performance. All experience will provide feedback to 8 GeV XFEL design, whose construction will start in April 2006. *http://www-xfel.spring8.or.jp

THOPA03	An Integrated Femtosecond Timing Distribution System for XFELs	laser, free-electron-laser, controls, FEL	2744
	J. Kim, J. Burnham, dc. Cheever, J. Chen, F.X. Kaertner MIT, Cambridge, Massachusetts M. Ferianis ELETTRA, Basovizza, Trieste F.O. Ilday Bilkent University, Bilkent, Ankara F. Ludwig, H. Schlarb, A. Winter DESY, Hamburg
	Tightly synchronized lasers and rf-systems with timing jitter in the few femtoseconds range are an important component of future x-ray free electron laser facilities. In this paper, we present an optical-rf phase detector that is capable of extracting an rf-signal from an optical pulse stream without amplitude-to-phase conversion. Extraction of a microwave signal with less than 10 fs timing jitter (from 1 Hz to 10 MHz) from an optical pulse stream is demonstrated. Scaling of this component to sub-femtosecond resolution is discussed. Together with low noise mode-locked lasers, timing-stabilized optical fiber links and compact optical cross-correlators, a flexible femtosecond timing distribution system with potentially sub-10 fs precision over distances of a few kilometres can be constructed. Experimental results on both synchronized rf and laser sources will be presented. A. Winter et al. "Synchronization of Femtosecond Pulses", Proceedings of FEL 2005.*J. Kim et al. "Large-Scale Timing Distribution and RF-Synchronization for FEL Facilities", Proc. of FEL 2004.
	Transparencies

THPPA01	High-precision Laser Master Oscillators for Optical Timing Distribution Systems in Future Light Sources	laser, feedback, FEL, diagnostics	2747
	A. Winter, P. Schmüser, A. Winter Uni HH, Hamburg J. Chen, F.X. Kaertner MIT, Cambridge, Massachusetts F.O. Ilday Bilkent University, Bilkent, Ankara F. Ludwig, H. Schlarb DESY, Hamburg
	Abstract to be supplied
	Transparencies

THESPA01	Before the Big Bang: An Outrageous New Perspective and its Implications for Particle Physics	background, radiation, LANL, LEFT	2759
	R. Penrose Mathematical Institute, Oxford
	The second law of thermodynaics implies that big bang must have been an extraordinarily precisely organized state. What was the geometrical nature of this state? How can we resolve, in any scientific way, the mystery of how such precision came about? In this talk, a novel (and perhaps outrageous) solution is suggested, which involves an examination of what is to be expected of the very remote future of our universe, with its observed accelerated expansion. Some possible observational consequences of the proposal will be indicated, together with some apparent implications for particle physics, some of which are non-standard.

THYFI01	Tevatron Ionization Profile Monitoring	injection, proton, antiproton, IPM	2777
	A. Jansson, K. Bowie, T. Fitzpatrick, R. Kwarciany, C. Lundberg, D. Slimmer, L. Valerio, J.R. Zagel Fermilab, Batavia, Illinois
	Ionization Profile monitors have been used in almost all machines at Fermilab. However, the Tevatron presents some particular challenges with its two counter-rotating, small beams, and stringent vacuum requirements. In order to obtain adequate beam size accuracy with the small signals available, custom made electronics from particle physics experiments was employed. This provides a fast (single bunch) and dead-timeless charge integration with a sensitivity in the femto-Coulomb range, bringing the system close to the single ionization electron detection threshold. The detector itself is based on a previous Main Injector prototype, albeit with many modifications and improvements. The first detector was installed at the end of 2005, with a second detector to follow during the spring shutdown. The ultimate is to continuously monitor beam size oscillations at injection, as well as the beam size evolution during ramp and squeeze.
	Transparencies

THOBFI01	A Sub 100 fs Electron Bunch Arrival-time Monitor System for FLASH	laser, pick-up, FEL, DESY	2781
	F. Loehl, K.E. Hacker, F. Ludwig, H. Schlarb, B. Schmidt DESY, Hamburg A. Winter Uni HH, Hamburg
	The stability of free-electron lasers and experiments carried out in pump-probe configurations depends sensitively on precise synchronization between the photo-injector laser, low-level RF-systems, probe lasers, and other components in the FEL. A measurement of the jitter in the arrival-time of the electron bunch with respect to the clock signal of a master oscillator is, therefore, of special importance. For this task, we propose an arrival-time monitor based on a beam pick-up with more than 10GHz bandwidth which permits measurements in the sub 100 fs regime. The RF-signal from the beam pick-up is sampled by an ultra-short laser pulse using a broad-band electro-optical modulator. The modulator converts the electron bunch arrival-time jitter into an amplitude modulation of the laser pulse. This modulation is detected by a photo detector and sampled by a fast ADC. By directly using the laser pulses from the master laser oscillator of the machine, any additional timing jitter is avoided. In this paper we present the layout of the system and first experimental results.
	Transparencies

THOBFI03	Record-high Resolution Experiments on Comparison of Spin Precession Frequencies of Electron Bunches Using the Resonant Depolarization Technique in the Storage Ring	positron, storage-ring, radiation, polarization	2787
	S.A. Nikitin, O. Anchugov, V.E. Blinov, A. Bogomyagkov, V.P. Cherepanov, G.V. Karpov, V. Kiselev, E. Levichev, I.B. Nikolaev, A.A. Polunin, E. Shubin, E.A. Simonov, V.V. Smaluk, M.V. Struchalin, G.M. Tumaikin BINP SB RAS, Novosibirsk
	The opportunity of performing an experiment on high precision comparison of the electron and positron anomalous magnetic moments following the VEPP-2M experiment is under study at the VEPP-4M storage ring. The record accuracy of 2x10-8 was obtained for comparison of spin precession frequencies in the experiment on resonant depolarization with simultaneously circulating electron bunches, two of them polarized and one unpolarized. It is the first time when the spreading of the spin precession frequency line (~5x10-7,) due to scattering of particle trajectories about the equilibrium orbit in a non-linear field of the storage ring, was presumably observed in experiments. We proposed and realized an RF scheme for controlled separation of the spin precession frequencies of two electron bunches; the first measurements using this scheme were made.
	Transparencies

THPCH008	The Non-linear Space Charge Field Compensation of the Electron Beam in the High Energy Storage Ring of FAIR	antiproton, space-charge, multipole, resonance	2802
	A.N. Chechenin, R. Maier, Y. Senichev FZJ, Jülich
	In the High Energy Storage Ring, a part of the FAIR project at GSI in Darmstadt, the internal target is used. To compensate the interaction of the beam with the target, the electron beam cooling is needed. However, together with the cooling, the non-linear space charge field of electron beam modifies the dynamic aperture. We investigate the possible schemes of this effect compensation using the multi-pole correctors on the HESR.

THPCH010	Electron Beam-laser Interaction near the Cathode in a High Brightness Photoinjector	laser, cathode, emittance, space-charge	2805
	M. Ferrario, G. Gatti INFN/LNF, Frascati (Roma) J.B. Rosenzweig UCLA, Los Angeles, California L. Serafini INFN-Milano, Milano
	The production of high charge short bunches in a high brightness photoinjector requires laser pulses driving the cathode with GW range peak power on a mm spot size. The resulting transverse electric field experienced by the electron beam near the cathode is of the order of 200-500 MV/m, well in excess of a typical RF accelerating field of 50-100 MV/m. We present here an analytical and computational study of the resultant beam dynamics. Simulations including the electron beam-laser interaction have been performed with the code HOMDYN taking into account the superposition of incident and reflected laser pulses as well as space charge fields. Under this conditions the emittance degradation is negligible, as predicted by analytical methods, but a longitudinal charge modulation occurs on the scale of the laser wavelength, in case of oblique incidence, driven by the longitudinal component of the laser field. Preliminary simulations up to the photoinjector exit show that charge modulation is transformed into energy modulation via the space charge field, which may produce enhanced microbunching effects when the beam is further compressed in a magnetic chicane.

THPCH018	Resonance Trapping, Halo Formation and Incoherent Emittance Growth due to Electron Cloud	emittance, simulation, resonance, LHC	2820
	E. Benedetto, E. Benedetto Politecnico di Torino, Torino G. Franchetti GSI, Darmstadt G. Rumolo, F. Zimmermann CERN, Geneva
	The pinched electron cloud introduces a tune shift along the bunch, which together with synchrotron motion, leads to a periodic crossing of resonances. The resonances are excited by the longitudinal distribution of the electron cloud around the storage ring. We benchmark the PIC code HEADTAIL against a simplified weak-strong tracking code based on an analytical field model, obtaining an excellent agreement. The simplified code is then used for exploring the long term evolution of the beam emittance, and for studying more realistic lattice models. Results are presented for the CERN SPS and the LHC.

THPCH025	Electron Cloud Self-consistent Simulations for the SNS Ring	proton, SNS, simulation, lattice	2832
	A.P. Shishlo, S.M. Cousineau, V.V. Danilov, S. Henderson, J.A. Holmes, M.A. Plum ORNL, Oak Ridge, Tennessee
	The electron cloud dynamics is simulated for the Spallation Neutron Source ring using the self-consistent electron-cloud model for long-bunched proton beams implemented in the ORBIT code. These simulations feature simultaneous calculations of the dynamics of the proton bunch and of the electron cloud, including electron multipacting using a realistic secondary emission surface model. The frequency spectra and growth rates of the proton bunch transverse instability are studied as functions of the RF cavity voltage. The effectiveness of an electron-cloud instability suppression system is also studied using an ORBIT model of the real feedback system. SNS is a collaboration of six US National Laboratories: Argonne National Laboratory (ANL), Brookhaven National Laboratory (BNL), Thomas Jefferson National Accelerator Facility (TJNAF), Los Alamos National Laboratory (LANL), Lawrence Berkeley National Laboratory (LBNL), and Oak Ridge National Laboratory (ORNL).

THPCH027	An Experimental Proposal to Study Heavy-ion Cooling in the AGS due to Beam Gas or the Intrabeam Scattering	ion, AGS, scattering, RHIC	2838
	D. Trbojevic, L. Ahrens, J. Beebe-Wang, M. Blaskiewicz, J.M. Brennan, W.W. MacKay, G. Parzen, T. Roser BNL, Upton, Long Island, New York
	Low emittance of not-fully-stripped gold(Z=79) Au+77 Helium-like ion beams from the AGS (Alternating Gradient Synchrotron) could be attributed to the cooling phenomenon due to inelastic intrabeam scattering [1]. The low emittance gold beams have always been observed at injection in the Relativistic Heavy Ion Collider (RHIC). There have been previous attempts to attribute the low emittance to a cooling due to the exchange of energy between ions during the inelastic intrabeam scattering. The Fano-Lichten theory[2] of electron promotion might be applied during inelastic collisions between helium like gold ions in the AGS. During collisions if the ion energy is large enough, a quasi-molecule could be formed, and electron excitation could occur. During de-excitation of electrons, photons are emitted and a loss of total bunch energy could occur. This would lead to smaller beam size. We propose to inject gold ions with two missing electrons into RHIC at injection energy and study the beam behavior with bunched and de-bunched beam, varying the RF voltage and the beam intensity. If the "cooling" is observed additional.

THPCH043	Jitter Studies for the FERMI@ELETTRA Linac	linac, ELETTRA, FEL, simulation	2880
	P. Craievich, S. Di Mitri ELETTRA, Basovizza, Trieste A. Zholents LBNL, Berkeley, California
	The FEL project FERMI@ELETTRA* will use the existing linac upgraded to 1.2GeV to produce photon pulses in the wavelength range between 100-10 nm by means of harmonic generation in a seeded scheme. FEL operations foresee stringent requirements for the stability of the global linac output parameters, such as the electron bunch arrival time, peak current, average energy and the slice electron bunch parameters, such as the slice peak current and slice average energy. In order to understand the sensitivity of these parameters to jitters of various error sources along the linac an elaborate study using tracking codes has been performed. As a result, we created a tolerance budget to be used as guidance in the design of the linac upgrade. In this paper we give a detailed description of the applied procedures and present the obtained results. *C. Bocchetta et al. "FERMI@ELETTRA - Conceptual Design for a Seeded Harmonic Cascade FEL for EUV and Soft X-rays", this conference.

THPCH047	Maps for Electron Clouds: Application to LHC	simulation, LHC, space-charge, CERN	2889
	T. Demma, S. Petracca U. Sannio, Benevento F. Ruggiero, G. Rumolo, F. Zimmermann CERN, Geneva
	Electron Cloud studies performed so far were based on very heavy computer simulations taking into account photoelectron production, secondary electron emission, electron dynamics, and space charge effects providing a very detailed description of the electron cloud evolution. In a recent paper* it has been shown that, for the typical parameters of RHIC, the bunch-to-bunch evolution of the electron cloud density can be represented by a cubic map. Simulations based on this map formalism are orders of magnitude faster than those based on usual codes. In this communication we show that the map formalism is also reliable in the range of typical LHC parameters, and discuss the dependence of the polynomial map coefficients on the physical parameters affecting the electron cloud (SEY, chamber dimensions, bunch spacing, bunch charge, etc.). *U. Iriso and S. Peggs. "Maps for Electron Clouds", Phys. Rev. ST-AB 8, 024403, 2005.

THPCH049	Simulation Study of Transverse Coupled-bunch Instabilities due to Electron Cloud in KEKB LER	simulation, KEKB, quadrupole, positron	2895
	X.W. Dong, S.-I. Kurokawa, K. Ohmi KEK, Ibaraki
	In this paper we report simulation results on the transverse coupled-bunch instabilities (TCBI) due to electron cloud at the KEKB Low Energy Ring (LER). The formation of electron cloud and related TCBI is investigated based on realistic solenoid field model. Studies on electron cloud in Quadrupole which could induce TCBI are also presented in this paper.

THPCH050	Further Studies on Betatron Sidebands due to Electron Clouds	betatron, synchrotron, feedback, KEKB	2898
	J.W. Flanagan, H. Fukuma, Y. Funakoshi, S. Hiramatsu, T. Ieiri, H. Ikeda, K. Ohmi, K. Oide, M. Tobiyama KEK, Ibaraki
	We have observed vertical betatron sidebands in the transverse beam spectra of positron bunches at the KEKB LER which are associated with the presence of electron clouds in single-beam studies, and which are also associated with a loss of luminosity when the KEKB beams are in collision. The sidebands may be signals of a fast head-tail instability due to short-range wakes within the electron cloud, providing a diagnostic for exploring the mechanism for transverse beam blow-up due to electron clouds. We report here on further studies on the behavior of the sidebands under varying beam conditions, including varying initial beam size below the beam blow-up threshold, chromaticity, RF voltage and fill pattern. J. W. Flanagan et al. PRL 94, 054801 (2005).**J. W. Flanagan et al. Proc. PAC05, p. 680 (2005).

THPCH051	The Effect of the Solenoid Field in Quadrupole Magnets on the Electron Cloud Instability in the KEKB LER	quadrupole, simulation, KEKB, dipole	2901
	H. Fukuma, J.W. Flanagan, T. Kawamoto, T. Morimoto, K. Oide, M. Tobiyama KEK, Ibaraki F. Zimmermann CERN, Geneva
	The electron cloud instability which causes vertical beam blowup in the KEKB LER is largely suppressed by applying a weak solenoid field to vacuum chambers in the drift region. However the blowup is still observed when the bunch spacing is reduced to 3.27 rf buckets or shorter. A question is where the remaining electron clouds are. To investigate the electron clouds in the quadrupole magnets, solenoids made of flat cables were developed and installed in 88 quadrupole magnets. The field strength of the solenoid is 17 Gauss. The effect of the solenoid field on the blowup is now under beam study. So far no clear effect of the solenoids on the luminosity and the sideband accompanied by the blowup is found. We report on the solenoid system, the results of the experiments and comparison of the experimental results with simulations.

THPCH053	Numerical and Experimental Study of Cooling-stacking Injection in HIMAC Synchrotron	ion, injection, scattering, simulation	2907
	E. Syresin JINR, Dubna, Moscow Region K. Noda NIRS, Chiba-shi S. Shibuya AEC, Chiba T. Uesugi KEK, Ibaraki
	The cooling-stacking injection at the HIMAC synchrotron was used to increase the intensity of Ar¹⁸⁺ ion beam. The beam stacking was realized in a horizontal free phase-space, which was created by the HIMAC electron cooler. The stack intensity of (1.5~2.5)·10⁹ ppp was accumulated at an injection intensity of (0.3~1.0)e9. The stack intensity was limitted by the ion lifetime. A peculiarity of present cooling-stacking experiments is related to lifetime difference by a factor of 2~3 of the stack and injected ions. The lifetime of stack ions is determined by vacuum pressure. The new injected ions were slowly lost at multiple scattering on residual gas atoms at diffusion heating in the vertical direction caused by the acceptance of 30pi-mm-mrad and a reduction of cooling force at large betatron amplitudes. The results of numerical simulations and experimental study of cooling-stacking injection on the HIMAC synchrotron are presented.

THPCH060	Simulation Study on the Energy Dependence of the TMCI Threshold in the CERN-SPS	simulation, impedance, SPS, space-charge	2922
	G. Rumolo, E. Métral, E.N. Shaposhnikova CERN, Geneva
	This paper concentrates on theoretical studies of Transverse Mode Coupling Instability at the SPS. It shows the expected thresholds based on a HEADTAIL tracking model and on impedance values estimated from previous measurements. First, the effect of space charge is addressed as an important ingredient at the low energies. Subsequently, the change of TMCI threshold possibly induced by a higher injection energy into the SPS (plausible according to the upgrade studies) is investigated and a scaling law with energy is derived.

THPCH069	BBU Calculations for Beam Stability Experiments on DARHT-2	BBU, simulation, impedance, induction	2943
	Y. Tang ATK-MR, Albuquerque, New Mexico K.C.D. Chan, C. Ekdahl LANL, Los Alamos, New Mexico T.P. Hughes Voss Scientific, Albuquerque, New Mexico
	The DARHT-2 (Dual-Axis Radiographic Hydrodynamics Test) facility is expected to produce a 2-kA, 20-MeV, 2-microsecond flattop electron beam pulse. Normal operation requires that the beam exit the accelerator with a normalized transverse emittance of less than 0.15-cm-rad. The beam break up (BBU) instability is a potentially serious effect for a high current linear accelerator. It arises from the interaction between the beam and the cavity modes of the accelerating cells. In support of the beam stability experiments, simulations of BBU for DARHT-2 using the Lamda code have been carried out. The simulations used experimental data for the transverse impedance of the cells. Lamda was benchmarked against results calculated with the LLNL code BREAKUP. For nominal transport parameters, simulation results showed that the BBU growth was not significant in changing the beam spot. For a magnetic field reduced by a factor of 5, BBU growth was over a factor of 100, and the image displacement effect was significant.

THPCH075	Simulation of the Electron Cloud for Various Configurations of a Damping Ring for the ILC	damping, simulation, wiggler, positron	2958
	M.T.F. Pivi, T.O. Raubenheimer, L. Wang SLAC, Menlo Park, California K. Ohmi KEK, Ibaraki R. Wanzenberg DESY, Hamburg A. Wolski Liverpool University, Science Faculty, Liverpool F. Zimmermann CERN, Geneva
	In the beam pipe of the Damping Ring (DR) of the International Linear Collider (ILC), an electron cloud may be first produced by photoelectrons and ionization of residual gasses and then increased by the secondary emission process. This paper reports about the work that has been done by the electron cloud assessment international task force group for the recommendation of the ILC Damping Rings baseline design, made in November 2005. We have carefully estimated the secondary electron yield (SEY) threshold for electron cloud build-up and estimated the related single^- and coupled-bunch instabilities that can be caused by the presence of electron cloud as a function of beam current and surface properties, for a variety of optics designs. The result of these studies was an important consideration in the choice of a 6-km design for the ILC damping rings. On the basis of the theoretical and experimental work, the baseline configuration specifies a pair of damping rings for the positron beam to mitigate the effects of the electron cloud.

THPCH076	Resistive Wall Wake Effect of a Grooved Vacuum Chamber	vacuum, impedance, SLAC, positron	2961
	G.V. Stupakov, K.L.F. Bane SLAC, Menlo Park, California
	To suppress the emission of secondary electrons in accelerators with positively charged beams (ions or positrons) it has been proposed to use a vacuum chamber that is longitudinally grooved (or, equivalently, one can say finned)/. One consequence of having such a chamber in an accelerator is an increased resistive wall impedance. In this paper, we calculate the resistive wall impedance of one such finned chamber, planned to be used in experimental studies of secondary emission suppression at SLAC. For rectangular fins, we use an analytical method based on a conformal mapping approach; we compare the results with a numerical solution of the field equation. We also numerically compute the impedance for rounded fins (as will be used in the SLAC experiment) and analyse how the impedance depends on geometric properties of the fins. A. A. Krasnov. Vaccum, vol. 73, p. 195, (2004).**G. Stupakov and M. Pivi. Preprint SLAC-TN-04-045, (2004).

THPCH080	Transverse Impedance of Small-gap Undulators for NSLS-II	impedance, undulator, vacuum, permanent-magnet	2970
	A. Blednykh, S. Krinsky, B. Podobedov, J.-M. Wang BNL, Upton, Long Island, New York
	We discuss the transverse impedance resulting from the use of small-gap undulators in the proposed NSLS-II storage ring. For superconducting undulators, the impedance arises due to the tapered elliptical vacuum chamber. For in-vacuum permanent magnet devices, the impedance results from a more complex geometry. We consider both cases and report results obtained using the electromagnetic simulation program GdfidL.

THPCH086	Design of a Local IP Orbit Feedback at HERA-e	feedback, proton, interaction-region, controls	2988
	J. Keil, O. Kaul, E. Negodin, R. Neumann DESY, Hamburg
	At the electron-proton collider HERA it is often observed that the proton emittance growth rate of colliding bunches is larger compared to non-colliding proton bunches. In addition the proton background rates are increasing when the two beams are brought into collision. There are indications that a contribution comes from closed orbit oscillations of the electron beam at the two IPs. In the arcs of HERA-e oscillation amplitudes of 100-200 micrometer with frequencies of 2-15 Hz and harmonics of 50 Hz are observed. In order to stabilize the orbit at the IPs in both planes a local digital orbit feedback system with a bandwidth of more than 20 Hz has been developed. The beam position at the IPs is measured with BPMs using dedicated electronics. The four local orbit bumps are produced by air-coil steerer magnets. The data are transmitted using SEDAC field bus lines to a central PC, which is used for the computation of the correction.

THPCH091	Status of the ELETTRA Global Orbit Feedback Project	feedback, controls, ELETTRA, closed-orbit	3003
	M. Lonza, D. Bulfone, R. De Monte, V. Forchi', G. Gaio ELETTRA, Basovizza, Trieste
	A fast digital feedback system is under development to stabilize the electron beam closed orbit at the ELETTRA storage ring in the band up to 300 Hz. In view of the implementation of the feedback, the existing orbit measurement system will be upgraded to allow for better accuracy in the beam position measurement and higher acquisition rate. A global correction algorithm running on a number of distributed processing units will correct the orbit using all of the storage ring steerer magnets. The status of the project development is given in this article.

THPCH132	EPU Assembly Based on Sub-cassettes Magnetic Characterization	undulator, polarization, synchrotron, radiation	3107
	G. Tosin, R. Basilio, J.F. Citadini, M. Potye LNLS, Campinas
	A procedure to speed up the magnetic field correction of an EPU type undulator is proposed and its results are shown. Such procedure consists in segmenting each one of the four magnetic blocks linear arrays (cassettes) in seven sub-cassettes and making their individual magnetic and mechanical characterization. One theoretical perfect sub-cassette, which is composed of four segments per period in Halbach configuration, is taken as the standard field profile. The peak fields and the fields integrated in each semi-period of one sub-cassette are chosen to be the optimization parameters. The magnetic blocks are displaced (virtual shims) to minimize the difference of the optimization parameters between the sub-cassette magnetic measurement and the standard profile. The sub-cassette magnetic measurements are performed with Hall probes, using the same bench employed in insertion devices characterization.

THPCH135	65 MEV Neutron Irradiation of ND-FE-B Permanent Magnets	radiation, proton, permanent-magnet, undulator	3116
	X.-M. Maréchal, T. Bizen JASRI/SPring-8, Hyogo-ken Y. Asano JAEA/SPring-8, Hyogo H. Kitamura RIKEN Spring-8 Harima, Hyogo
	Rare-earth permanent magnets are now playing a major role in accelerator technology, from the development of beam transport systems magnets to their extensive use in synchrotron radiation sources and free electron lasers. Unfortunately, operating in a high radiation environment, rare-earth permanent magnets are subject to demagnetization caused by direct and scattered radiation. The lifetime of these components is therefore a major issue: as a result, the number of studies to clarify the demagnetization mechanism or to test materials of interest for a particular application under specific conditions of irradiation has increased in recent years. However, so far, neutron irradiation experiments have been mainly carried out with reactors, were neutrons have a wide, but mainly low, energy spectrum. We present here the results obtained at the TIARA facility of the Japan Atomic Energy Research Institute, a spalliation source of mono highly energetic neutrons. Four types of Nd-Fe-B permanent magnets (Neomax™ 35EH, 32AH, 27VH and 44H) representing a wide range of characteristics (remanence and coervicity) have been studied.

THPCH152	Temporal Quantum Efficiency of a Micro-structured Cathode	laser, cathode, target, simulation	3149
	V. Nassisi, F. Belloni, G. Caretto, D. Doria, A. Lorusso, L. Martina, M.V. Siciliano INFN-Lecce, Lecce
	In this work the experimental and simulation results of photoemission studies for photoelectrons are presented. The cathode used was a Zn disc having the emitting surface morphologically modified. Two different excimer lasers were employed like energy source to apply the photoelectron process: XeCl (308nm, 10ns) and KrF (248nm, 20ns). Experimental parameters were the laser fluence (up to 70 mJ/cm2) and the anode-cathode voltage (up to 20 kV). The output current was detected by a resistive shunt with the same value of the characteristic impedance of the sistem, about 100 ?. In this way, our device was able to record fast current signals. The best values of global quantum efficiency were approximately 5x 10^-6 for XeCl and 1x 10^-4 for KrF laser, while the peaks of the temporal quantum efficiency were 8x 10^-6 and 1.4x10-4, respectively. The higher efficiency for KrF is ascribed to higher photon energy and to Schottky effect. Several electron-beam simulations using OPERA 3-D were carried out to analyze the influence of the geometrical characteristics of the diode. Simulating the photoemission by cathodes with micro-structures the output current was dependent on cathode roughness. L. Martina et al. Rev. Sci. Instrum., 73, 2552 (2002).

THPCH153	Production of Temporally Flat Top UV Laser Pulses for SPARC Photoinjector	laser, target, emittance, diagnostics	3152
	M. Petrarca, P. Musumeci INFN-Roma, Roma I. Boscolo, S. Cialdi INFN-Milano, Milano G. Gatti, A. Ghigo, C. Vicario INFN/LNF, Frascati (Roma) M. Mattioli Università di Roma I La Sapienza, Roma
	In the SPARC photoinjector, the amplified Ti:Sa laser system is conceived to produce an UV flat top pulse profile required to reduce the beam emittance by minimizing the non-linear space charge effects in the photoelectrons pulse. Beam dynamic simulations indicate that the optimal pulse distribution must be flat top in space and time with 10 ps FWHM duration, 1 ps of rise and fall time and a limited ripple on the plateau. In a previous work~\cite{loose} it was demonstrated the possibility to use a programmable dispersive acousto-optics (AO) filter to achieve pulse profile close to the optimal one. In this paper we report the characterization of the effects of harmonics conversion on the pulse temporal profile. A technique to overcome the harmonics conversion distortions on the laser pulses at the fundamental wavelength in order to obtain the target pulse profile is explained too. Measurements and simulations in the temporal and spectral domain at the fundamental laser wavelength and at the second and third harmonics are presented in order to validate our work. It is also described a time diagnostic device for the UV pulses. *H. Loos et al. "Temporal E-Beam Shaping in an S-Band Accelerator", Proc. Particle Accelerator Conference, p.642, 2005, Knoxville, TN, USA.

THPCH154	Development of Pulsed Laser Super-cavity for Compact High Flux X-ray Sources	laser, photon, storage-ring, target	3155
	K. Sakaue, M. Washio RISE, Tokyo S. Araki, Y. Higashi, Y. Honda, T. Taniguchi, J. Urakawa KEK, Ibaraki M.K. Fukuda, M. Takano NIRS, Chiba-shi H. Sakai ISSP/SRL, Chiba N. Sasao Kyoto University, Kyoto
	Pulsed-laser super-cavity is being developed at KEK-ATF for the application of a compact high brightness x-ray source based on Laser Compton Scattering. We use a Fabry-Perot optical cavity with a pulsed laser. The cavity increases a laser effective power, and at the same time, stably makes a small laser spot in side the cavity. In addition, the pulsed-laser gives much higher peak power. Thus, this scheme will open up a new possibility for building a compact high-brightness x-ray source, when collided with an intense bunched electron beam. We are now planning to build such an x-ray source with a 50MeV multi-bunch linac and a 42cm Fabry-Perot cavity using pulse stacking technology. We actually finished construction of the 50MeV linac and will start its operation in the spring, 2006. Development of the pulsed-laser super-cavity and future plan of our compact x-ray source will be presented at the conference.

THPCH155	High-quality Proton Beam Obtained by Combination of Phase Rotation and the Irradiation of the Intense Short-pulse Laser	laser, ion, proton, target	3158
	S. Nakamura, Y. Iwashita, A. Noda, T. Shirai, H. Souda, H. Tongu Kyoto ICR, Uji, Kyoto S. Bulanov, T. Esirkepov, Y. Hayashi, M. Kado, T. Kimura, M. Mori, A. Nagashima, M. Nishiuchi, K. Ogura, S. Orimo, A. Pirozhkov, A. Sagisaka, A. Yogo JAEA, Ibaraki-ken H. Daido, A. Fukumi JAEA/Kansai, Kizu-machi Souraku-gun Kyoto-fu Z. Li NIRS, Chiba-shi A. Ogata, Y. Wada HU/AdSM, Higashi-Hiroshima T. Tajima JAEA/FEL, Ibaraki-ken T. Takeuchi AEC, Chiba
	Ion production from laser-induced plasma has been paid attention because of its high acceleration gradient (>100GeV/m) compared with conventional RF accelerator. Its energy spectrum is Maxwell-Boltzmann distribution with high-energy cut-off, which limited its application. The phase rotation scheme, which rotates laser produced ions by an RF electric field synchronous to the pulse laser in the longitudinal phase space, was applied to proton beam up to 0.9MeV emitted from Ti foil with 3mm thickness irradiated by focused laser-pulse with peak intensity of 9 � 1017W/cm2. Multi-peaks with ~6% width (FWHM) were created and intensity multiplication up to 5 was attained around 0.6MeV region. The proton production process by the intense short-pulse laser has been optimized with use of time of flight measurement of proton beam detected by a plastic scintillation counter, which is specially shielded from the heavy background of electrons and X-rays induced by the intense laser. We have succeeded in on-line measurement of such a proton signal by the detector for the first time, which played an essential role for the investigation of phase rotation scheme.

THPCH156	SNS Transverse and Longitudinal Laser Profile Monitors Design, Implementation and Results	laser, SNS, SCL, linac	3161
	S. Assadi ORNL, Oak Ridge, Tennessee
	SNS is using a Nd:YAG laser to measure transverse profiles at nine-stations in the 186-1000 MeV Super-Conducting LINAC (SCL) and a Ti:Sapphire mode-locked laser to measure longitudinal profiles in the 2.5 MeV Medium Energy Beam Transport (MEBT). The laser beam is scanned across the H^- beam to photo-neutralize narrow slices. The liberated electrons are directly collected to measure the transverse or longitudinal beam profiles. We have successfully measured the transverse and longitudinal profiles at all stations. The SCL laser system uses an optical transport line that is installed alongside the 300 meter super-conducting LINAC to deliver laser light at nine locations. Movement of the laser light in the optical transport system can lead to problems with the profile measurement. We are using telescopes to minimize the oscillations and active feedback system on mirrors to correct the drifts and movements. In this paper we present our implementation and beam profiles measured during SCL commissioning. We also discuss future improvements, drift/vibration cancellation system, as well as plan to automate subsystems for both the transverse and the longitudinal profiles.

THPCH158	A Phased-locked S.A.M. Mode-locked Laser for the ELSA Photoinjector	laser, ELSA, photon, linac	3164
	V. Le Flanchec, P. Balleyguier CEA, Bruyères-le-Châtel
	A new laser oscillator has been developed for the ELSA photoinjector. It is a fibered-diode-pumped mode-locked Nd:YVO4 laser, with a completely passive cooling design. Mode-locking is achieved by a saturable absorber mirror. Such a passive laser oscillator must be synchronized with the ELSA electron bunches. A phased-locked loop has been developed for that purpose. We present the main design aspects resulting from the high stability requirement of ELSA. The first electron spectra measurements show the high level of energy stability achieved. We also present improvements in the laser injection system leading to a higher transverse stability, a more uniform cathode illumination, and a better transmission of the whole system.

THPCH161	Status of the Polarized Electron Gun at the S-DALINAC	laser, gun, cathode, quadrupole	3173
	C. Heßler, M. Brunken, J. Enders, H.-D. Gräf, G. Iancu, Y. Poltoratska, M. Roth TU Darmstadt, Darmstadt W. Ackermann, W.F.O. Müller, N. Somjit, B. Steiner, T. Weiland TEMF, Darmstadt K. Aulenbacher IKP, Mainz
	Aiming at an extension of the experimenting capabilities for nuclear structure physics at low momentum transfer at the superconducting Darmstadt electron linear accelerator S-DALINAC, a polarized electron gun is being constructed. The new injector will be able to supply the S-DALINAC with 100 keV polarized electrons and should complement the present, unpolarized thermionic source. The design requirements are a degree of polarization of at least 80%, a mean current intensity of 0.06 mA and a 3 GHz cw structure. The basic design of the gun was adapted from the source of polarized electrons at MAMI, Mainz, and optimized in various simulations. The active material is a strained layer GaAs crystal which is exposed to an 830 nm pulsed laser beam. We report on the status of the polarized source, the preparation setup and a test beam line. K. Aulenbacher et al., Nucl. Instrum. Meth. A 391, 498 (1997).

THPCH170	Reduction of Dark Current in SPring-8 Linac	linac, gun, simulation, synchrotron	3194
	T. Kobayashi, T. Asaka, H. Dewa, H. Hanaki, A. Mizuno, S. Suzuki, T. Taniuchi, H. Tomizawa, K. Yanagida JASRI/SPring-8, Hyogo-ken
	In the SPring-8 linac, removal of dark currents generated from an injector part has been studied to enhance the bunch purity of stored beam in the SPring-8 storage ring. We already succeeded in reduction of the dark currents from a thermionic electron gun by a beam deflector of parallel plate electrodes. However, dark currents are also generated in accelerating structures due to the high electric fields. We have been studying removal of the dark currents generated from the first accelerating structure by solenoid coils covering it.

THPCH174	Multipactor Electron Gun with CVD Diamond Cathodes	DIAMOND, cathode, gun, ion	3203
	J.Y. Zhai, C.-X. Tang, S. Zheng TUB, Beijing
	A Multipactor Electron Gun (MEG) is developed for the high power microwave generation in the Accelerator Lab of Tsinghua University. This paper presents the recent experimental results of the S-band MEG using hydrogen-terminated and CsI-terminated CVD diamond cathodes. The gun design, cathode preparation and high power experiment are described. An electron beam with 5 μs macro-pulse, 10 Hz repetition rate, greater than 900 mA beam current was obtained.calculation and computer simulation. The properties of the secondary electron emission cathodes are also discussed.

THPCH179	High Power Cavity Combiner for RF Amplifiers	simulation, storage-ring, scattering, coupling	3215
	F. Pérez, B. B. Baricevic, D. Einfeld, P. Sanchez ALBA, Bellaterra J.P. Buge, M.L. Langlois, G. Peillex-Delphe TED, Thonon
	A new approach of RF power combination has been developed for the ALBA Storage Ring RF system: a three-port high power Cavity Combiner (CaCo). A prototype has been successfully built and tested in Thales Electron Devices, Thonon, France. The final goal is to combine the power of two 80 kW IOTs at 500 MHz in order to provide a total output power of 160 kW. In this paper, a summary of the analytical and simulation analysis of the expected behaviour is given. In basis of that, the decided geometric constraints and the final design configuration chosen for the prototype production are explained. Low power test results and matching, and finally the high power test performances, are shown. As a conclusion, the RF system of the ALBA Storage Ring will incorporate the CaCo concept to obtain the needed power per cavity from the combination of two IOTs.

THPCH187	Analysis and Reduction Electromagnetic Interference to ICTs Caused by Pulsed Power Supply Excitation in NSRRC	kicker, injection, power-supply, storage-ring	3239
	Y.-H. Liu, J.-C. Chang, J.-R. Chen, Y.-C. Lin NSRRC, Hsinchu
	The purpose of this paper is to eliminate the Electromagnetic Interference (EMI) from kicker power supply. Analyses of the EMI source and the propagation path are the beginning missions. The radiated and conducted EMI both affected the Integral Current Transformer (ICT) normal operation because of the space limitation for TLS in NSRRC. The ICT is to measure injection efficiency, thus, ICT located just behind the kickers and using the common girder. The EMI signals therefore are much higher than the electron beam currents, and the integral values of the sensor are not correct. For reducing and eliminating the interference of electromagnetic waves, a hybrid segregation and grounding method was used. The EMI wrapper was enclosed the ICT and its high frequency amplifier separately to prevent the radiated EMI from the space. The grounding paths provided the possible stray current dredge to the ground loop. It reduced the stray current spread to the subsystems next to the kickers. The EMI therefore reduced 99%, and the injection efficiency could be calculated successfully. The elimination of the EMI from kicker itself will be the next step in the future.

THPLS002	X-ray and Optical Diagnostic Beamlines at the Australian Synchrotron Storage Ring	diagnostics, storage-ring, synchrotron, controls	3263
	M.J. Boland, R.T. Dowd, G. LeBlanc, M.J. Spencer, Y.E. Tan, A. Walsh ASP, Clayton, Victoria
	Two diagnostic beamlines have been designed and constructed for the Australian Synchrotron Storage Ring. One diagnostic beamline is a simple x-ray pinhole camera system, with a BESSY II style pinhole array, designed to measure the beam divergence, size and stability. The second diagnostic beamline uses an optical chicane to extract the visible light from the photon beam and transports it to various instruments. The end-station of the optical diagnostic beamline is equipped with a streak camera, a fast ICCD camera, a CCD camera and a fill pattern monitor. The beamline design and some commissioning measurements are presented.

THPLS004	Canadian Light Source Update	coupling, undulator, emittance, lattice	3269
	L. O. Dallin, M.J. Sigrist, T. Summers CLS, Saskatoon, Saskatchewan
	The Canadian Light Source (CLS) storage ring has been operating routinely since commissioning was completed in the spring of 2004. Beam currents up to 230 mA have been achieved with the single superconducting RF cavity. With steady improvement beam lifetimes (1/e) of 10 hours at 170 mA and 0.25% coupling are now possible. In the last year the vertical tune was increased by 1 integer to produce a smaller vertical beam size in the ID straight sections. This year the horizontal tune will be increased to reduce the beam emittance. The vertical coupling has been reduced both globally and locally using a skew quadrupole response technique. A wide range of photons energies are provided by an initial complement of five insertion devices (IDs) and and two infrared (IR) ports. The 5 m straights have room for two IDs. The light cones from these IDs are separated by about 1.5 mrad by "chicaning" the electron beam in the straights. To date two IDs have been installed in one straight using the chicaning technique. As well, a superconducting wiggler and a in-vacuum undulator have been installed and commissioned. An AppleII type elliptically polarizing undulator will be installed in April 2006.

THPLS012	Commissioning of the Australian Synchrotron Injector RF Systems	booster, linac, controls, single-bunch	3293
	C. Piel, K. Dunkel, J. Manolitsas, D. Trompetter, H. Vogel ACCEL, Bergisch Gladbach M.J. Boland, R.T. Dowd, G. LeBlanc, M.J. Spencer, Y.E. Tan ASP, Clayton, Victoria
	On December 16, 2003 the contract for the design, manufacture, installation and commissioning of the turnkey injector system for the Australian Synchrotron Project was awarded to industry. ACCEL Instruments is delivering the turnkey 100MeV linac and the booster RF system. Commissioning of the linac for ASP was performed in December 2005, right after successful commissioning of the Diamond Light Source injection linac. The 500MHz booster cavity and related low level RF system will be commissioned after installation of the booster is finalised in early 2006. The paper will present design and layout information, as well as commissioning results. Commissioning of the Diamond Pre-Injector Linac (this conference).

THPLS014	Status of the Metrology Light Source	microtron, storage-ring, injection, synchrotron	3299
	K. Buerkmann-Gehrlein, M. Abo-Bakr, W. Anders, P. Budz, O. Dressler, V. Duerr, J. Feikes, H.G. Hoberg, D. Krämer, P. Kuske, R. Lange, J. Rahn, T. Schneegans, D. Schueler, E. Weihreter, G. Wuestefeld BESSY GmbH, Berlin R. Klein, G. Ulm PTB, Berlin
	For more than 25 years, the Physikalisch-Technische-Bundesanstalt (PTB) uses synchrotron radiation at the storage rings BESSY I and II for photon metrology in the spectral range of UV to x-rays. Since decommissioning of BESSY I (1999), there is a gap in the spectral range of UV and EUV wavelength due to the higher electron energy of BESSY II. Thus, in 2003, the Metrology Light Source (MLS), a low energy electron storage ring, was approved, as central instrument in the future Willy Wien Laboratory (WWL). Design, construction and operation of the MLS are realized by BESSY, based on the PTB requirements for a permanent accessible radiometry source, optimized for the spectral range between UV up to VUV. The MLS is tuneable in energy between 200 MeV and 600 MeV, designed for currents between 1pA up to 200mA. Civil construction of WWL in the close vicinity to BESSY is nearing completion. The first MLS components will be installed in spring 2006, commissioning of the 100MeV Microtron is scheduled for summer 2006, while commissioning of the storage ring will start in spring 2007. Regular user operation will begin in January 2008. A status and an overview on the construction of the MLS are

THPLS015	Spectral Fingerprints of Femtoslicing in the THz Regime	laser, resonance, radiation, undulator	3302
	K. Holldack, S. Khan, T. Quast BESSY GmbH, Berlin R. Mitzner Universität Muenster, Physikalisches Institut, Muenster
	Femtosecond (fs) THz pulses are observed as a consequence of laser-induced energy modulation of electrons in the BESSY II storage ring in order to generate fs x-ray pulses via femtoslicing. The THz pulses are spectrally characterized by step-scan and rapid scan FTIR spectroscopy. The temporal shape of the laser-induced density modulation is reconstructed from the THz spectra. It is studied as a function of laser and storage ring parameters and monitored over several revolutions. The results are compared with numerical simulations. The THz spectra acquired over a few seconds are used to optimize the laser parameters for achieving minimum x-ray pulse lengths in femtoslicing experiments. A. Zholents and M. Zoloterev, PRL 76 (1996), 912.

THPLS016	Bunch Shape Diagnostics Using Femtoslicing	laser, CSR, radiation, undulator	3305
	K. Holldack, T. Quast BESSY GmbH, Berlin S. Khan Uni HH, Hamburg R. Mitzner Universität Muenster, Physikalisches Institut, Muenster
	Laser-energy modulation of relativistic electron bunches as needed for the BESSY femtosecond (fs) x-ray source is accompanied by the emission of fs THz pulses. The total THz intensity probes the square of the longitudinal particle density within a slice of ~50 fs length (fwhm). The bunch shape can be directly monitored while sweeping the time delay between laser and bunch clock. The method is demonstrated for bunch lengths between 3 and 30 ps (rms) in different operation modes of BESSY II. The use of THz signals from successive turns and the influence of periodic bursts of coherent synchrotron radiation, which lock to the laser pulse under certain conditions, are discussed. The method is used for setting up and stabilizing the temporal overlap between a fs-laser and a relativistic electron bunch. K. Holldack et al., Phys. Rev. Lett. (2006), accepted Dec. 2005.

THPLS018	FLUKA Calculations of Neutron Spectra at BESSY	target, shielding, vacuum, radiation	3311
	K. Ott BESSY GmbH, Berlin
	The synchrotron light source BESSY consists of a 50 MeV microtron, a full energy synchrotron and a 1.9 GeV storage ring. The electron losses during injection causes electromagnetic cascades within the stainless steel of the vacuum system and the aluminum chambers of the undulators. The cascade-produced neutrons result from giant resonances, quasi-deuteron fissions and photo-pion productions. The cross sections of the evaporation reactions of neutrons are an order of magnitude higher than the cross sections of the latter two reaction channels. The energy distribution of the giant resonance neutrons has a maximum at about 1 MeV in comparison with 100 - 200 MeV of the high energy neutrons. At electron accelerators outside the shielding wall, half of the neutron dose is often determined by the more penetrating high energy part of the neutron fluence. We used the particle interaction and transport code FLUKA for the calculations of the energy distribution of both the fluence and the dose inside and outside the shielding wall for different realistic scenarios. From the integrated spectra we get the calibration factor to determine the total neutron dose from the measurements directly.

THPLS019	The Metrology Light Source: an Electron Storage Ring Dedicated to Metrology	radiation, storage-ring, photon, synchrotron	3314
	R. Klein, G. Ulm PTB, Berlin P. Budz, K. Buerkmann-Gehrlein, J. Rahn, G. Wuestefeld BESSY GmbH, Berlin
	PTB, the German National Metrology Institute, in close cooperation with BESSY, is currently setting up a low-energy electron storage ring (200 MeV up to 600 MeV electron energy), the Metrology Light Source MLS, which will be dedicated to metrology and technology development in the UV and EUV spectral range which synchrotron radiation. The MLS has been designed by BESSY according to PTB specifications. User operation is scheduled to begin in 2008. Currently, the building, housing the storage ring, is nearly completed, and all major parts of the storage ring and the injection system have been ordered or have already been delivered. The MLS will be equipped with all the instrumentation necessary to measure the storage ring parameters needed for the calculation of the spectral photon flux according to the Schwinger theory with low uncertainty, enabling PTB to operate the MLS as a primary source standard. Moreover, calculations show, that the MLS is ideally suited for the production of coherent synchrotron radiation in the far IR and THz region. We give a status update on the construction, the instrumentation for the measurement of the storage ring parameters and calculations for a low-

THPLS031	Elettra Top-up Requirements and Design Status	injection, insertion, insertion-device, ELETTRA	3350
	F. Iazzourene, S. Bassanese, A. Carniel, K. Casarin, R. De Monte, M. Ferianis, F. Giacuzzo, M. Lonza, G. Tromba, A. Vascotto ELETTRA, Basovizza, Trieste
	Elettra is a 2.5 GeV third generation light source in operation since 1993. To provide more stable beams to the users, we plan to operate in the so-called top-up injection mode. The first step is the substitution of the present 1GeV linac by a 100 MeV pre-injector linac and a fast cycling 2.5 GeV synchrotron booster foreseen to be in operation in 2007. The present paper will report on the requirements for the top-up operation in terms of radiation safety, diagnostics H/S, timing, modality, etc. and the design status. In particular, a new BPM system, based on the log-ratio detectors, has been successfully commissioned on the present transfer line and linac and is ready to be deployed on the new injector and to be used by the new foreseen shot to shot transfer line booster to storage trajectory feedback system. Furthermore, in order to flatten the storage ring filling, the top-up charge will be integrated where needed. Preliminary measurements on the bunch by bunch measurement methods of the storage ring bunch charge are reported. “Elettra New Full Energy Injector Status Report”, these proceedings.

THPLS034	Top-up Operation of SPring-8 Storage Ring with Low Emittance Optics	optics, injection, emittance, brilliance	3359
	H. Tanaka, N. Kumagai, M. Masaki, S. Matsui, H. Ohkuma, T. Ohshima, M. Oishi, J. Schimizu, K. Soutome, S. Takano, M. Takao, H. Takebe, K. Tsumaki, H. Yonehara, T. Yorita, C. Zhang JASRI/SPring-8, Hyogo-ken
	We have succeeded in providing stable and three-times more brilliant x-ray to users by combining top-up operation with low emittance optics. The optics with the low emittance of 3nmrad was first applied to the user operation in November 2002. Although the low emittance provided the brilliant x-ray, the extremely short beam lifetime much disturbed the precise experiments. Moreover, the aborted electron beam damaged the part of vacuum chamber at the beam injection section. The low emittance operation was thus suspended in October 2003. By improving design of the vacuum chamber and introducing the top-up injection, the problems for the stable operation were resolved, and then the top-up operation with the low emittance optics has been first achieved at SPring-8. This paper illustrates how we achieved this sophisticated operation by explaining the following three essential investigations: (1) reduction of natural emittance for a storage ring with four magnet-free long straight sections, (2) protection of vacuum chamber from aborted electron beam, and (3) consistency to the top-up operation. The obtained performance is also described in the paper.

THPLS037	Beam Position and Angular Monitor for Undulator by Using SR Monitor Technique	undulator, focusing, injection, radiation	3368
	T. Mitsuhashi, M. Tadano KEK, Ibaraki
	We presented a beam position monitor by using SR monitor technique in the last PAC05. In this monitor, a visible SR in far tail of the undulator spectrum is extracted by a water-cooled beryllium mirror. We applied a focusing system to observe a beam position in the undulator through an optical image of beam. We continue further study of this monitor, and this time, we add the afocal system like a Kepler type telescope to measure the angular deviation of the beam. This system converts the angular deviation of optical axis of input ray into position deviation, and we can measure an angular deviation of the beam through its position deviation on the CCD. The results show us this method is applicable to monitor an angular deviation of beam in the undulator independent from position deviation, and gap change of undulator has no effect for the beam position monitoring.

THPLS040	Present Status of the UVSOR-II	laser, undulator, emittance, FEL	3374
	M. Katoh, K. Hayashi, M. Hosaka, A. Mochihashi, J. Yamazaki UVSOR, Okazaki T. Hara RIKEN Spring-8 Harima, Hyogo M. Shimada KEK, Ibaraki
	UVSOR electron storage ring, which was a 2nd-generation synchrotron radiation (SR) light source for VUV and soft x-ray region, has been renewed as UVSOR-II at the beginning of 2003. Because of the improvement, the beam emittance has been reduced from 165nm-rad to 27nm-rad, and longer straight sections with smaller vertical betatron functions have been provided. In addition to a helical/linear undulator, two in-vacuum undulators have been installed in the long straight sections at the improvement. New variably polarized undulator will be also installed in summer 2006. Improvement of booster synchrotron will be also performed in summer 2006 with aiming to top-up operation in the future. Now UVSOR-II has been operated in 750MeV with the emittance of 27nm-rad in daily users runs. Not only the development of high quality SR beams but also basic investigations for new light source have been performed; development of storage ring FEL and investigation of intense THz burst SR. Bunch slicing experiment with a Ti:Sa laser (800nm) has also been started since 2005, and experiments for coherent harmonic generation and coherent SR generation with the laser-beam interaction have been performed.

THPLS041	Observation of Intense Terahertz Synchrotron Radiation produced by Laser Bunch Slicing at UVSOR-II	laser, radiation, CSR, synchrotron	3377
	M. Katoh, M. Hosaka, K. Kimura, A. Mochihashi, M. Shimada UVSOR, Okazaki T. Hara RIKEN Spring-8 Harima, Hyogo T. Takahashi KURRI, Osaka Y. Takashima Nagoya University, Nagoya
	We have performed electron bunch slicing experiments using a femto-second high power pulse laser in the UVSOR-II electron storage ring. As the pulse laser system we have used a Ti:Sa laser whose wavelength is 800 nm, typical pulse duration is 100 fs, pulse repetition is 1 kHz and typical average power is 2W. The laser is operated in mode-locked condition and synchronized with the electron beam revolution. The laser pulse is injected into an undulator section and it goes along with the electron bunch. By adjusting the radiation wavelength of the undulator to the laser wavelength, the electron beam energy can be partially modulated in the electron bunch. We have observed THz synchrotron radiation (SR) light from a bending magnet that is downstream of the interaction region. The SR light contains extremely intense THz pulse radiation that is synchronized with the laser injection. The extremely high intensity strongly suggests that the THz pulses are coherent synchrotron radiation from the electron bunch with a hole because of the laser-beam interaction.

THPLS042	Observation of THz Synchrotron Radiation Burst in UVSOR-II Electron Storage Ring	radiation, synchrotron, synchrotron-radiation, CSR	3380
	A. Mochihashi, M. Hosaka, M. Katoh, K. Kimura, M. Shimada UVSOR, Okazaki T. Takahashi KURRI, Osaka Y. Takashima Nagoya University, Nagoya
	Very intense THz synchrotron radiation bursts have been observed in single-bunch operation in the UVSOR-II electron storage ring. The observation was performed in an infrared beam line in UVSOR-II by using a liquid-He-cooled In-Sb hot-electron bolometer that has a good response time of several microseconds. Thanks both to the beam line and the detector, it is clearly observed that the intense bursts have typical macroscopic and microscopic temporal structure. Macroscopically, it is clearly observed that the bursts tend to be generated with quasi-periodic structure in which the period tends to depend on the beam intensity. From a microscopic point of view, each burst has also quasi-periodic structure in itself, and the period almost corresponds to the half value of the inverse of the synchrotron oscillation frequency. The peak intensity of the bursts was about 10000 times larger than that of ordinary synchrotron radiation in the same wavelength region. The extremely high intensity strongly suggests that the bursts are coherent synchrotron radiation, although the radiation wavelength was much shorter than the electron bunch length. Y. Takashima et al., Jpn. J. Appl. Phys. 44, No.35 (2005) L1131.

THPLS044	Preliminary Experiment of the Thomson Scattering X-ray Source at Tsinghua University	laser, scattering, photon, linac	3386
	Y.-C. Du, Cheng. Cheng. Cheng, Q. Du, Du.Taibin. Du, W.-H. Huang, Y. Lin, C.-X. Tang, S. Zheng TUB, Beijing
	A preliminary experiment of the Thomson scattering x-ray source is being planned and constructed to generate short-pulsed, tunable x-rays in the range of ~4.5 kev by Thomson scattering of laser photons from a relativistic electron beam. Laser photons of ? = 1064 nm are Thomson backscattered by a 16MeV electron beam from a 16MeV Backward Travelling Wave (BTW) electron linac. The laser is derived from a 2J,10ns Nd:YAG laser. The parameters of electron beam and laser have been measured. The simulated and experiment results are described in this paper.

THPLS055	Effects of Phase 1 Insertion Devices at the ALBA Project	undulator, resonance, lattice, wiggler	3407
	M. Belgroune, M. Muñoz CELLS, Bellaterra (Cerdanyola del Vallès)
	The ALBA new third generation light source offers a large number of straight sections to its community of users. Three types of straights will be available, 4 of 8 m, 12 of 4.2 m and 8 of 2.6 m. The compact lattice of a 268 m circumference ring is now mature and its main components are already fixed. We discuss here the beam dynamics studies performed for Phase 1 Insertion Devices (IDs) where two helical devices HU71, two in-vacuum undulators U21 and a multipole wiggler have been modeled using the kick map approach. This allowed defining the suitable compensation scheme in a machine where the vertical focusing is mainly controlled by the gradients in the dipole magnets. In addition, the Touschek lifetime computations and the identification of the limiting resonances using Frequency Map Analysis showed how strong the working point is in the presence of these IDs. Tolerances on the multipolar components due to the fields' roll-off have also been defined and allowed the progress in the IDs design.

THPLS058	MAX III Commissioning	vacuum, injection, dipole, betatron	3416
	M. Eriksson, M. Bergqvist, M. Brandin, L.-J. Lindgren, M. Sjöström, S. Thorin MAX-lab, Lund
	Some of the features of the 700 MeV MAX III synchrotron radiation storage ring are presented, and the commissioning of this ring is described.

THPLS059	Status of the MAX IV Light Source Project	undulator, storage-ring, linac, radiation	3418
	M. Eriksson, M. Berglund, K.I. Blomqvist, M. Brandin, T. Hansen, D. Kumbaro, L.-J. Lindgren, L. Malmgren, M. Sjöström, H. Svensson, H. Tarawneh, S. Thorin, E.J. Wallén, S. Werin MAX-lab, Lund B. Anderberg AMACC, Uppsala
	The present development of the accelerator part of the MAX IV synchrotron radiation project is presented. The main features of the 3 GeV injector linac and the two storage rings operated at different electron energies to cover a broad spectral range of high brilliance undulator radiation are described in some detail. A third ring, the existing MAX III ring, is planned to be transferred to the new facility. The preparation of the injector linac to serve as a free electron laser source and the major sub-systems of the facility are also presented.

THPLS064	Design Concept of the Vacuum System for the 3 GeV Taiwan Photon Source	vacuum, photon, simulation, storage-ring	3433
	G.-Y. Hsiung, C.K. Chan, C.-H. Chang, H.P. Hsueh, T.L. Yang NSRRC, Hsinchu J.-R. Chen NTHU, Hsinchu
	The design concept of the vacuum system for the electron storage ring of the Taiwan Photon Source (TPS), 518.4 m in circumference, is described. The vacuum system for the synchrotron light source not only meets the specifications of an electron beam energy of 3 GeV and a beam current at 400 mA but also provides a safety factor of 1.7 (~ 500 mA) at 3.3 GeV at the upper bound. The vacuum system for the storage ring is built with consideration of the following features: (1) Large aluminum bending chambers to simplify the ultra-high vacuum (UHV) structure; (2) Absorbers located as far from the source as possible to reduce the heat load and associated yield of photon stimulated desorption (PSD) as well as the photoelectron; (3) Vacuum pumps located in the antechamber and closed to the absorbers to increase the localized pumping efficiency and to minimize the impedance of beam ducts; (4) Quantity of flanges and bellows is significantly reduced. Configuration of the pumps, results of the simulation for the pressure and thermal stress, and the criteria of the design will be discussed.

THPLS065	Optimization for Taiwan Photon Source Electron Beam Position Monitors through Numerical Simulation	simulation, photon, synchrotron, synchrotron-radiation	3436
	H.P. Hsueh, C.-H. Chang, G.-Y. Hsiung, C.-K. Kuan, T.-S. Ueng NSRRC, Hsinchu J.-R. Chen NTHU, Hsinchu
	One of the key steps toward successfully building the newly proposed 3rd generation synchrotron radiation research facility, Taiwan Photon Source (TPS), is to optimize the design of the high resolution electron beam position monitors through numerical simulation. With more advanced electromagnetic simulation tool like MAFIA tailored specifically for particle accelerator, the design for the high resolution electron beam position monitors can be tested in such environment before actually fabricated and physically tested. The design goal of our high resolution electron beam position monitors is to achieve 0.1 micron resolution if allowed by engineering limitations. The design consideration to achieve this 0.1 micron resolution goal will also be discussed. The first design has been carried out and the correlated simulations were also carried out with MAFIA. The results are presented and discussed here. Sensitivity as high as 200 has been achieved at 500 MHz. Further study will also be described.

THPLS066	Improvement on the Single Bunch Operation of the TLS Injector	cathode, gun, booster, linac	3439
	J.-Y. Hwang, C.-S. Fann, K.-T. Hsu, S.Y. Hsu, K.H. Hu, S.H. Lee, K.-K. Lin, K.-B. Liu, Y.-C. Liu NSRRC, Hsinchu
	The improvement of the TLS (Taiwan Light Source) injector on single bunch operation is presented in this study. Limited by the existing design of the TLS injector, the single bunch operation was not optimized in terms of bunch purity for specific users of TLS. A high voltage pulser was implemented to improve the situation. This pulser has been integrated into the high-voltage-deck electronics of electron gun for single bunch generation. Both high-voltage pulses and the associated electron bunches are monitored with a wideband digital oscilloscope. The result shows that the bunch purity can be greatly improved by using the newly installed pulser. It also greatly eliminates the beam losses while injected into the booster ring.

THPLS069	Preliminary Design of the TPS Linac to Booster Transfer Line	booster, linac, injection, focusing	3448
	Y.-C. Liu, H.-P. Chang, C.-S. Fann, K.-T. Hsu, S.Y. Hsu, K.-K. Lin, K.-B. Liu, G.-H. Luo NSRRC, Hsinchu
	The preliminary design of the LTB (linac to booster) transfer line of the proposed TPS (Taiwan Photon Source) project is considered in this study. The layout presented in this report is based on the booster lattice and the choice of linac parameters. These parameters are adopted from previous report of booster design and typical commercial available products of linac. The simulation result indicates that the desired optical functions at a given location can be readily obtained by varying the appropriate focusing strength of quadrupoles. It provides tuning capability to match various possible options of optical functions at injection location. This report is presented together with design consideration of a set of beam diagnostics instruments.

THPLS075	Progress in Development of Kharkov X-Ray Generator	storage-ring, injection, quadrupole, lattice	3457
	A.Y. Zelinsky, V.P. Androsov, E.V. Bulyak, A. Dovbnya, I.V. Drebot, P. Gladkikh, V.A. Grevtsev, Yu.N. Grigor'ev, A. Gvozd, V.E. Ivashchenko, I.M. Karnaukhov, N. Kovalyova, V.P. Kozin, V. Lapshin, V.P. Lyashchenko, V. Markov, N.I. Mocheshnikov, V.B. Molodkin, A. Mytsykov, I.M. Necklyudov, F.A. Peev, O.V. Ryezayev, A.A. Shcherbakov, A. Shpak, V.L. Skirda, V.A. Skomorokhov, Y.N. Telegin, V.I. Trotsenko, O.D. Zvonarjova NSC/KIPT, Kharkov A. Agafonov, A.N. Lebedev LPI, Moscow J.I.M. Botman TUE, Eindhoven R. Tatchyn SLAC, Menlo Park, California
	Over the past year the design, development and construction of NSC KIPT X-ray generator NESTOR has been in progress. NESTOR is a new type radiation source on the base of Compton scattering and a 40 - 225 MeV electron storage ring. Electrons are injected in the storage ring at 100 MeV and ramped up to final energy 225 MeV. It is supposed that stored electron beam current will be of about 200 mA. Along with use of Nd:Yag laser of 10 W average power which was developed by High-Q laser firm and optical resonator with accumulation gain of about 1000 it allows to provide X-ray radiation flux up to 1011 phot/s. NESTOR is the cooperative facility and is supported both as well Ukrainian government as NATO SfP project #977982. It is supposed that NESTOR will be in operation in the middle of 2007 year. The status of the project and main facility systems are described in the report.

THPLS079	Bunch Diffusion Measurements at the Advanced Light Source	photon, storage-ring, injection, lattice	3466
	F. Sannibale, W.E. Byrne, C.-W. Chiu, J. Guo LBNL, Berkeley, California J.S. Hull, O.H.W. Siegmund, A.S. Tremsin, J. Vallerga UCB, Berkeley, California
	In storage ring based synchrotron light sources, a long beam lifetime is usually a fundamental requirement for a high integrated brightness. The dynamic aperture and the momentum acceptance of lattices are carefully studied and maximized as much as possible for a long lifetime performance. On the other hand, large momentum acceptance and dynamic aperture increase the probability that a particle diffuses from one bunch to another. Diffusion can represent a severe limitation for those experiments where the samples have long relaxation times requiring empty buckets between bunches. At the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory we have characterized the particle diffusion for the present lattice in order to evaluate its impact on a special user operation dedicated to these long relaxation time experiments and on the incoming top-off injection mode for the ALS.

THPLS097	Model of the CSR Induced Bursts in Slicing Experiments	laser, CSR, undulator, SLAC	3502
	G.V. Stupakov, S.A. Heifets SLAC, Menlo Park, California
	In a recent experiment on 'femtoslicing' at the Advanced Light Source in LBNL, it has been observed that the beam slicing initiates correlated bursts of coherent synchrotron radiation (CSR) of the beam. In this paper, we suggest a model describing such bursts. The model is based on the linear theory of the CSR instability in electron rings. We describe how an initial perturbation of the beam generated by the laser pulse evolves in time when the beam is unstable due to the CSR wakefield. Although this model does not give quantitative predictions, it qualitatively explains the evolution of the induced CSR bursts.

THPLS103	Investigations of the Longitudinal Phase Space at PITZ	booster, PITZ, gun, simulation	3517
	J.R. Roensch, J. Rossbach Uni HH, Hamburg K. Abrahamyan, G. Asova, J.W. Baehr, G. Dimitrov, H.-J. Grabosch, J.H. Han, O. Kalekin, S. Khodyachykh, S.A. Korepanov, M. Krasilnikov, V. Miltchev, A. Oppelt, B. Petrosyan, S. Riemann, L. Staykov, F. Stephan DESY Zeuthen, Zeuthen D. Lipka, R. Richter BESSY GmbH, Berlin
	The correlation between the positions of the particles in the bunch and their longitudinal momenta has to be analysed in order to optimize photo injectors for Free-Electron Lasers (FELs). Longitudinal phase space measurements at the upgraded PITZ facility* will be presented in this paper. Measurements of the complete longitudinal phase space and its projections behind the gun are compared with simulations. Momentum measurements after a booster cavity will be discussed. *A.Oppelt et al. "Status and first results from the upgraded PITZ facility", FEL Conf. 2005.

THPLS104	Optimization Studies of the FERMI@ELETTRA Photoinjector	emittance, laser, cathode, gun	3520
	G. Penco, M. Trovo ELETTRA, Basovizza, Trieste S.M. Lidia LBNL, Berkeley, California
	In the framework of the FERMI@ELETTRA project the electron beam characteristics strongly depend from the two operating modes: FEL1 (100nm-40nm) with a photon pulse around 100fs and FEL2 (40nm-10nm) with a long photon pulse (~1ps) having a high resolution spectral bandwidth. We present the multi-particles tracking code results concerning the photoinjector, which includes the RF gun and the first two accelerating sections, describing two possible electron bunch lengths, satisfying the two FEL operation modes. The injector optimization relative to the two options, aimed to produce a very low projected emittance (around 1 mm mrad) with a uniform behavior of the slice parameters (emittance and energy spread) along the bunch, is described in this paper. Moreover sensitivity studies, time and energy jitters estimations are presented for both cases.

THPLS107	Possibility of the Beam Injection Using a Single Pulsed Sextupole Magnet in Electron Storage Rings	injection, sextupole, storage-ring, quadrupole	3526
	Y. Kobayashi, K. Harada KEK, Ibaraki
	Recently, we succeeded in the beam injection using a single pulsed quadrupole magnet (PQM) at the Photon Factory Advanced Ring (PF-AR). The PQM enables us to inject the beam into the storage ring without the local bump by several pulsed dipole magnets. In addition, since the stored beam is not kicked when the beam passes through the magnetic center of the PQM, we can avoid the coherent beam oscillation, which is often produced by the unclosed local bump. It is important for the top-up injection in electron storage rings as synchrotron radiation sources. However, in the case of the PQM, we have the problem that the beam profile slightly changes turn-by-turn after the excitation of the PQM. In order to solve it, we investigated the possibility of the beam injection using a single pulsed sextupole magnet (PSM) instead of the PQM. Here, we will present the simulation of the beam injection using the PSM.

THPLS108	Performance Test of RF Photo-Cathode Gun at the PAL	gun, laser, emittance, cathode	3529
	J.H. Park, J.Y. Huang, C. Kim, I.S. Ko, Y.W. Parc, S.J. Park PAL, Pohang, Kyungbuk X.J. Wang BNL, Upton, Long Island, New York
	A RF photo-cathode (RF PC) gun with 1.6 cell cavity is installed for the fs-FIR (Femto-second Far Infrared Radiation) facility being built at the Pohang Accelerator Laboratory (PAL). A short, intense, and low emittance electron beams are produced by the RF PC gun. Performance test of the gun is done include the measurement of RF chraterizations such as a resonant frequency, a mode separation, and etcs. The diagnostics of the beam according to the beam parameters such as phase, charge, and energy, and emittance are done. In this article, we present the measurement results of the RF charaterizations and the beam parameter diagnostics of the RF PC gun at the PAL.

THPLS109	Measurements and Diagnostics on the MAX Recirculator	radiation, linac, FEL, injection	3532
	M. Brandin, B. Nelander, S. Werin MAX-lab, Lund
	The MAX Recirculator is a unique accelerator, a two-pass linac at 500 MeV, that operates as injector for three storage rings. Here are presented some discussions on measurments of beam parameters such as emittance, energy spread, and bunch length. We describe what measurements are done, by wich methods, results, and how they can be improved. Also, we make an analysis of What methods and hardware are needed to perform the measurements that can't be done with the equipment in place today.

THPLS112	Electron Multipacting Observation and Simulation in the APS PAR	simulation, vacuum, resonance, beam-loading	3541
	C. Yao, Y.-C. Chae ANL, Argonne, Illinois
	The particle accumulator ring (PAR) has both fundamental and 12th harmonic rf systems. Gap voltage fluctuations were experienced after vacuum work was performed on the PAR during a maintenance period. This has caused intermittent beam instability and prevented us from running the PAR fundamental rf system at normal power level. Our investigation has concluded that the problem was caused by electron multipacting in the center vacuum chamber of the cavity. We were able to suppress the multipacting by applying a solenoid field in the suspected region. Computer simulation is underway in order to find the location and the parameter range of the multipacting. In this paper we report the experimental observations and results of the simulation relevant to the phenomena.

THPLS115	Simulation and Optimisation of a 100 mA DC Photo-Injector	emittance, gun, cathode, ASTRA	3550
	F.E. Hannon, C. Hernandez-Garcia Jefferson Lab, Newport News, Virginia
	A prototype 100mA injector is presently being designed and manufactured jointly between Thomas Jefferson National Accelerator Facility (J-Lab) and Advanced Energy Systems (AES). This paper discusses the physics optimisation and performance of the injector, which has been studied using the space-charge tracking code ASTRA. The objective is to operate the 7MeV injector with 135pC electron bunches at 748.5MHz repetition rate. We show that the longitudinal and transverse electron bunch properties can be realised within the constraints of the design.

THPLS125	A Concept on Electric Field Error Compensation for the ANKA Superconductive Undulator	undulator, photon, permanent-magnet, simulation	3577
	D. Wollmann, T. Baumbach, A. Bernhard University of Karlsruhe, Karlsruhe S. Casalbuoni, MH. Hagelstein, B.K. Kostka, R. Rossmanith FZK, Karlsruhe G. Gerlach University of Dresden, Institute for Solid-State Electronics, Dresden F. Schoeck, E. Steffens, M. Weisser University of Erlangen-Nürnberg, Physikalisches Institut II, Erlangen
	In April 2005 a superconductive undulator test device, the so-called SCU14 (period length 14 mm, 100 periods) was installed at ANKA. Before installation, the magnetic field was measured and documented. This was the first test of a superconductive undulator in a storage ring and the dominating questions to be answered were related to the interaction of the undulator with the beam. The field quality was of lower importance and will be improved by a modified mechanical fabrication technique at the next superconductive undulators. Nevertheless, after finishing the fundamental beam tests the question was discussed how one would improve the field quality (minimize the phase error) of the existing undulator by local correction devices. The concepts could be used later in a weaker form for local field corrections at future undulators, if necessary.

THPLS126	Construction and Testing of a Pair of Focusing Undulators for ALPHA-X	undulator, focusing, insertion-device, insertion	3580
	B.J.A. Shepherd, J.A. Clarke CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
	ALPHA-X is a four-year project shared between several research groups in the UK to build a laser-plasma accelerator and produce coherent short-wavelength radiation in an FEL. A pair of undulators for the project have been designed and built by ASTeC at Daresbury Laboratory. The undulators are 1.5m long, 100 period permanent magnet devices with a minimum gap of 3.5mm, a peak field of 0.7T and a two-plane focusing design. The devices were modelled using RADIA, and data from the magnet block manufacturer was used to sort the blocks. To optimise the trajectory in the real devices, magnetic testing (using Hall probe and flipping coil techniques) and block swapping has been performed in Daresbury's dedicated insertion device test facility. The measurements agree well with the models, and the undulators will perform well within specification.

THPLS130	Thermal Neutron Demagnetization of NdFeB Magnets	vacuum, ion, photon, undulator	3589
	R.W. Klaffky DOE/OFES, Germantown, Maryland R.M. Lindstrom NIST, Gaithersburg, Maryland B. Maranville, R. Shull National Institute of Standards and Technology, Gaithersburg, Maryland B.J. Micklich, J.H. Vacca ANL, Argonne, Illinois
	At the Advanced Photon Source at Argonne National Laboratory, NdFeB insertion device magnets have shown losses of magnetization on a few straight sections where the largest electron beam losses occur due to limiting vacuum chamber apertures. In the worst case, these magnetization losses were evident after a three month operational period. To isolate the effect that thermal neutrons have on these magnets, the magnetization and coercivity were studied for two NdFeB grades as a function of dose from 7.5 x 10(12) to 6 x 10(13) neutrons/cm2. After saturation, the remanent magnetization was found to decrease linearly with the logarithm of the dose. At a dose of 7.5 x 10(12) neutrons/cm2.sec, there was already a 43 percent magnetization loss for the N45 grade and a 15 percent loss for the N48 grade. There was no apparent change in coercivity with dose. The change in remanent magnetization is a consequence of boron thermal neutron capture through the 10B(n,alpha)7Li reaction, which generates MeV energy alpha particles and lithium ions.

THPLS133	Simulations of Electromagnetic Undulator for Far Infrared Coherent Source of TTF at DESY	undulator, radiation, FIR, simulation	3595
	E. Syresin, V.V. Borisov, E.A. Matushevsky, N.A. Morozov JINR, Dubna, Moscow Region O. Grimm, M.V. Yurkov DESY, Hamburg J. Rossbach Uni HH, Hamburg
	A perspective extension of the VUV FEL user facility at DESY is infrared coherent source on the base of electromagnetic undulator. The undulator consists of 9 periods, period length is 40 cm long, and peak magnetic field is up to 1.2 T. With the energy of electron beam of 500 MeV maximum radiation wavelength is about 200 mkm. An important feature of the beam formation system of the VUV FEL is the possibility to produce ultra-short, down to 50 mkm rms electron bunches. Such short bunches produce powerful coherent radiation with multi-megawatt power level. FIR coherent source operates in a parasitic mode utilizing electron beam passed VUV undulator. Generation of two-colors by a single electron bunch reveals unique possibility to perform pump-probe experiments with VUV and FIR radiation pulses. In this report we present simulations of the undulator magnetic system and beam dynamics.

THPLS139	In-Achromatic Superconducting Wiggler in Taiwan Light Source: Installation and Test Results	wiggler, storage-ring, cryogenics, vacuum	3613
	C.-H. Chang, C.-C. Chang, H.-P. Chang, H.-H. Chen, J.-R. Chen, T.-C. Fan, G.-Y. Hsiung, M.-H. Huang, C.-S. Hwang, J.C. Jan, F.-Y. Lin NSRRC, Hsinchu
	In order to increase more high flux x-ray photon beams for the Taiwan Light Source, the achromatic superconducting wiggler has been installed and tested in a 1.5 GeV storage ring. The 3.1 Tesla superconducting wiggler will be operated in a 4.5 K liquid helium cryogenic system. In this work, the operation experience and test results of the achromatic superconducting wiggler are described.

FRXBPA01	HERA and the Next Generation of Lepton-ion Colliders	proton, luminosity, lepton, collider	3621
	F.J. Willeke DESY, Hamburg
	This talk will present a summary of the physics insights gained from the lepton-hadron collider HERA and review major beam dynamics issues and lessons learned in view of LHC operation, including technical aspects related to the large number of superconducting magnets or the influence of various design choices on the overall machine performance. It will also address future plans for lepton-ion colliders, including eRHIC at BNL and the CEBAF-based ELIC, with emphasis on their luminosity reach and challenges. The talk will also mention possible high energy lepton-ion collisions, for example colliding a 1 TeV proton (or ion) beam from the Tevatron or Super-SPS with a 20-75 GeV electron beam from the ILC or CLIC (first stage).
	Transparencies

FRYBPA01	Overview of Single Pass Free Electron Lasers	radiation, FEL, laser, undulator	3636
	C. Pellegrini UCLA, Los Angeles, California
	The presentation will cover world wide status of single pass free electron lasers. A general status will be given of the projects. Common themes will be discussed, as will the challenges of these themes. Unique characteristics of individual projects will also be covered. Here the emphasis will be on a description of novel and challenging techniques: for example examples seeding of the FEL, different types of guns for high brightness electron beam production, very short or very long pulse production, etc.
	Transparencies