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MOPKF033 Operational Improvements in the ESRF Injection Complex injection, undulator, wiggler, radiation 375
 
  • Y. Papaphilippou, P. Elleaume, L. Farvacque, L. Hardy, G.A. Naylor, E. Plouviez, J.-L. Revol, B.K. Scheidt, V. Serriere
    ESRF, Grenoble
  The ESRF injection complex, comprising a 200MeV linac, a booster accelerator with a top energy of 6GeV and two transfer lines, has been routinely injecting beam to the storage ring since the beginning of its operation. The newly implemented injection with ‘‘front-end open'' triggered several operational improvements in order to maximise the reliability of the complex. A series of diagnostics (sychnotron light monitors, striplines, fast current transformers) were implemented allowing the measurement and monitoring of several components of the injected beam. New optics models were constructed and several application systems as the closed orbit correction or tune measurements have been upgraded. The operational procedures of injection at 100MeV in the booster and the injection efficiency maximisation were renewed and improved. Further developments for the uninterrupted operation of the storage ring during injection, such as the bunch cleaning in the booster were successfully tested.  
 
MOPKF034 Status of the Development of Superconducting Undulators at the ESRF injection, undulator, wiggler, radiation 378
 
  • E.J. Wallén, J. Chavanne, P. Elleaume
    ESRF, Grenoble
  This note describes the present status of the development of superconducting undulators at the ESRF. Magnetic models of superconducting undulators suitable for the ESRF storage ring have been developed and evaluated. The superconducting undulators studied are horizontally polarizing undulators with a flat field profile and the vertical physical aperture of the undulator is 6 mm. Both 2D models of the local field in a period of the undulator and 3D models of the complete superconducting undulator, including the end sections and current leads, have been evaluated. The practical limit for the obtainable magnetic field has been estimated from the known performance of superconducting wire available from the cabling industry. This note also describes the conceptual design of the cryostat of the superconducting undulator and estimations of the expected heat load to the cryostat at different filling modes of the storage ring.  
 
MOPKF035 Stabilization of the Pulsed Regimes on Storage Ring Free Electron Laser: The Cases of Super-ACO and Elettra injection, wiggler, electron, damping 381
 
  • C. Bruni, D. Garzella, G. Lambert, G.L. Orlandi
    LURE, Orsay
  • E. Allaria, R. Meucci
    INOA, Firenze
  • S. Bielawski
    PhLAM/CERCLA, Villeneuve d'Ascq Cedex
  • M.-E. Couprie
    CEA/DSM, Gif-sur-Yvette
  • M. Danailov, G. De Ninno, B. Diviacco, M. Trovò
    ELETTRA, Basovizza, Trieste
  • D. Fanelli
    KTH/NADA, Stockholm
  • L. Giannessi
    ENEA C.R. Frascati, Frascati (Roma)
  In a Storage Ring Free Electron Laser (SRFEL) a relativistic electron beam interacts with the magnetostatic periodic field of an undulator, thus emitting synchrotron radiation. The light is stored in an optical cavity and amplified during successive turns of the particles in the ring. The laser intensity may appear as a "continuous wave (cw)" or show a stable pulsed behaviour depending on the value of the temporal detuning, i.e. the difference between the electron beam revolution period and the round trip of the photons in the cavity. It was recently shown, that the loss of stability in a SRFEL occurs through an Hopf bifurcation [*]. This observation opens up the perspective of introducing a derivative self-controlled feedback to suppress locally the bifurcation and enlarge the region of stable signal. A feedback of this type has been implemented on Super-ACO and shown to produce a significant and reproducible extension of the stable "cw" region. We review here these results and discuss new experiments performed on the Super-ACO and ELETTRA SRFELs.

* G. De Ninno and D. Fanelli, Phys. Rev. Lett. in press; M.E. Couprie et al. Nucl. Instrum.and Meth. A., in press

 
 
MOPKF036 Wideband Infrared FEL injection, undulator, wiggler, vacuum 384
 
  • J.-M. Ortega, F. Glotin, R. Prazeres
    LURE, Orsay
  The infrared free-electron laser offers the advantage of a potential large tunability since the FEL gain itself remains subtantially high throughout the infrared spectral range, provided that the electron beam quality remains sufficient at low energy. Moreover, the reflectivity of metal mirrors used in the optical cavity remains close to unity from the near infrared up to the microwave range. The main limitation comes from the diffraction of the optical beam due to the finite size of the vacuum chamber of the undulator and other optical cavity elements. The undulator magnetic gap, and thus magnetic chamber inner heigth, cannot be made arbitrarily large since one needs a K parameter sufficiently large to produce a large wavength tunability (typically K > 2). The diffraction losses can however be further reduced by using an elliptical vacuum chamber inside the undulator and elliptical, instead of spherical, mirrors. Then the optical beam is partially guided inside the chamber. Working in this regime at CLIO, we have obtained an FEL tunable from 3 to 120 μm by operating the accelerator between 50 and 14 MeV. This is the largest spectral range ever obtained with a single optical cavity. We plan to use larger mirrors to further reduce the diffraction produced at the edges of the undulator chambers in order to increase the maximum wavelength to approximately 200 μm  
 
MOPKF037 FERMI@ELETTRA: 100 nm - 10 nm Single Pass FEL User Facility injection, wiggler, linac, vacuum 387
 
  • R.J. Bakker, C. Bocchetta, P. Craievich, G. D'Auria, M. Danailov, G. De Ninno, S. Di Mitri, B. Diviacco, G. Pangon, L. Rumiz, L. Tosi, V. Verzilov, D. Zangrando
    ELETTRA, Basovizza, Trieste
  The FERMI@ELETTRA project is an initiative from ELETTRA, INFM and other Italian institutes, to construct a single-pass FEL user-facility for the wavelength range from 100 nm (12 eV) to 10 nm (124 eV), to be located next to the third-generation synchrotron radiation facility ELETTRA in Trieste, Italy. The project is concentrated around the existing 1.2-GeV S-band linac, i.e., the injector for the storage ring. Presently the linac is only operational for approximately 2 hours per day. The remaining time is available for the construction and operation of an FEL but modifications and operation must be planned such that operation of the storage ring can be guaranteed until the completion of a new full-energy injector (spring 2006). At this moment the FEL project evolves from a conceptional design stage towards a technical design and the actual implementation. Key issues are: incorporation of the free-electron laser in the infrastructure of the Sincrotrone Trieste, adjustments of the linac to facilitate FEL operation, required additional civil engineering, undulator design, FEL seeding options, and beamline design. This paper serves as an overview of the project in combination with a discussion of the critical issues involved.  
 
MOPKF039 The ELETTRA Superconducting Wiggler injection, linac, vacuum, damping 390
 
  • L. Tosi, C. Knapic, D. Zangrando
    ELETTRA, Basovizza, Trieste
  A 3.5 Tesla 64 mm period superconducting wiggler has been installed in the ELETTRA storage ring as a photon source for a future X-ray diffraction beamline. After several technological upgrades, a series of measurements were carried out to characterize the device and its effects on the electron beam, such as optics distortion and dynamic aperture. A description of the upgrades and measurements are presented.  
 
MOPKF040 Effect of Electron-beam Feedbacks on the ELETTRA Storage-ring Free-electron Laser injection, electron, laser, linac 393
 
  • M. Trovò, D. Bulfone, M. Danailov, G. De Ninno, B. Diviacco, V. Forchi', M. Lonza
    ELETTRA, Basovizza, Trieste
  • L. Giannessi
    ENEA C.R. Frascati, Frascati (Roma)
  As is well known, the stability of a storage-ring free-electron laser is strongly related to that of the electron beam. With respect to second-generation devices, such as Super ACO and UVSOR, the free-electron laser at ELETTRA is characterized by a noticeably higher gain and, consequently, shows to be much more sensitive to electron-beam instabilities. In order to counteract the impact of such instabilities, both a longitudinal multibunch and a local orbit feedbacks have been implemented for free-electron laser operation. Aim of this paper is to report on the beneficial effect of these feedback systems on the laser performance.  
 
MOPKF041 SPARC Photoinjector Working Point Optimization, Tolerances and Sensitivity to Errors injection, electron, laser, emittance 396
 
  • M. Ferrario, M.E. Biagini, M. Boscolo, V. Fusco, S. Guiducci, M.  Migliorati, C. Sanelli, F. Tazzioli, C. Vaccarezza
    INFN/LNF, Frascati (Roma)
  • L. Giannessi, L. Mezi, M. Quattromini, C. Ronsivalle
    ENEA C.R. Frascati, Frascati (Roma)
  • J. Rosenzweig
    UCLA, Los Angeles, California
  • L. Serafini
    INFN-Milano, Milano
  A new optimization of the SPARC photoinjector, aiming to reduce the FEL saturation length, is presented in this paper. Start to end simulations show that with 1.1 nC charge in a 10 ps long bunch we can deliver at the undulator entrance a beam having 100 A in 50% of the slices (each slice being 300 mm long) with a slice emittance ?1 mm, thus reducing the FEL-SASE saturation length to 12 m at 500 nm wavelength. In addition the stability of the nominal working point and its sensitivity to various type of random errors, under realistic conditions of the SPARC photoinjector operation, are discussed. A systematic scan of the main parameters around the operating point, performed with PARMELA code interfaced to MATLAB, shows that the probability to get a projected emittance exceeding 1 mm is only 10 % and the slice emittance remains below 1 mm in all cases.  
 
MOPKF042 Status of the SPARC Project injection, electron, linac, vacuum 399
 
  • M. Ferrario, D. Alesini, M. Bellaveglia, S. Bertolucci, M.E. Biagini, R. Boni, M. Boscolo, M. Castellano, A. Clozza, G. Di Pirro, A. Drago, A. Esposito, D. Filippetto, V. Fusco, A. Gallo, A. Ghigo, S. Guiducci, M. Incurvati, C. Ligi, F. Marcellini, 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, M. Mauri
    INFN/LASA, Segrate (MI)
  • I. Boscolo, F. Brogli, S. Cialdi, C. De Martinis, D. Giove, C. Maroli, V. Petrillo, M. Romé, L. Serafini
    INFN-Milano, Milano
  • L. Catani, E.C. Chiadroni, A. Cianchi, S. Tazzari
    Università di Roma II Tor Vergata, Roma
  • F. Ciocci, G. Dattoli, A. Doria, F. Flora, G.P. Gallerano, L. Giannessi, E. Giovenale, G. Messina, L. Mezi, P.L. Ottaviani, L. Picardi, M. Quattromini, A. Renieri, C. Ronsivalle
    ENEA C.R. Frascati, Frascati (Roma)
  • D. Dowell, P. Emma, C. Limborg-Deprey, D. Palmer
    SLAC, Menlo Park, California
  • D. Levi, M. Mattioli, G. Medici
    Università di Roma I La Sapienza, Roma
  • M.  Migliorati, A. Mostacci, L. Palumbo
    Rome University La Sapienza, Roma
  • P. Musumeci, J. Rosenzweig
    UCLA, Los Angeles, California
  • M. Nisoli, S. Stagira, S. de Silvestri
    Politecnico/Milano, Milano
  The aim of the SPARC project is to promote an R&D activity oriented to the development of a high brightness photoinjector to drive SASE-FEL experiments at 500 nm and higher harmonics generation. It has been proposed by a collaboration among ENEA-INFN-CNR-Universita‘ di Roma Tor Vergata-INFM-ST and funded by the Italian Government with a 3 year time schedule. The machine will be installed at LNF, inside an existing underground bunker. It is comprised of an rf gun driven by a Ti:Sa laser to produce 10-ps flat top pulses on the photocathode, injecting into three SLAC accelerating sections. We foresee conducting investigations on the emittance correction and on the rf compression techniques up to kA level. The SPARC photoinjector can be used also to investigate beam physics issues like surface-roughness-induced wake fields, bunch-length measurements in the sub-ps range, emittance degradation in magnetic compressors due to CSR. We present in this paper the status of the design activities of the injector and of the undulator. The first test on diagnostic prototypes and the first experimental achievements of the flat top laser pulse production are also discussed.  
 
MOPKF043 An Ultra-high Brightness, High Duty Factor, Superconducting RF Photoinjector injection, vacuum, damping, alignment 402
 
  • M. Ferrario
    INFN/LNF, Frascati (Roma)
  • J. Rosenzweig
    UCLA, Los Angeles, California
  • J. Sekutowicz
    DESY, Hamburg
  Recent advances in superconducting rf technology, and an improved understanding of rf photoinjector design optimization make if possible to propose a specific design for a superconducting rf gun which can simultaneously produce both ultra-high peak brightness, and high average current. Such a device may prove to be a critical component of next generation x-ray sources such as self-amplified spontaneous emission free-electron lasers (SASE FEL) and energy recovery linac (ERL) based systems. The design presented is scaled from the present state-of-the-art normal conducting rf photoinjector that has been studied in the context of the LCLS SASE FEL. Issues specific to the superconducing rf photoinjector, such as accelerating gradient limit, rf cavity design, and compatibility with magnetic focusing and laser excitation of a photocathode, are discussed.  
 
MOPKF044 Wake Fields Effects in the Photoinjector of the SPARC Project injection, vacuum, damping, alignment 405
 
  • V. Fusco, M. Ferrario, B. Spataro
    INFN/LNF, Frascati (Roma)
  • M.  Migliorati, L. Palumbo
    Rome University La Sapienza, Roma
  When a bunch travels off axis across structures whose shape is not uniform, such as RF cavity or bellows, generates longitudinal and transverse wake fields. In addition transverse time dependent fields (like transverse RF components and wake fields ) may induce correlated slice centroids displacement, so that each slice centroid motion become affected also by space charge forces generated by the next slices. An evaluation of the emittance degradation and induced energy spread in the SPARC injector is performed with an improved version of the code Homdyn and the results are discussed. A comparison with other codes (ABCI, PARMELA 3D) to validate our model is also presented.  
 
MOPKF045 Cesium Telluride and Metals Photoelectron Thermal Emittance Measurements Using a Time-of-flight Spectrometer injection, emittance, vacuum, damping 408
 
  • D. Sertore, D. Favia, P. Michelato, L. Monaco, P. Pierini
    INFN/LASA, Segrate (MI)
  The thermal emittance of photoemitted electrons in an RF gun is a crucial parameter for short wavelength FELs and future high luminosity electron colliders. An estimate of the thermal emittance of semiconductor and metal samples, commonly used as photocathodes, has been assessed using a Time-Of-Flight spectrometer. In this paper we present the analysis, based on angle resolved photoemission measurements, of both the cesium telluride (Cs2Te) photocathode films as used at the TESLA Test Facility, and polycrystalline metals. These latter measurements, at different laser wavelengths, are used to validate both our experimental apparatus and the thermal emittance reconstruction technique developed.  
 
MOPKF046 Photoelectron RF Gun Designed as a Single Cell Cavity injection, gun, emittance, cathode 411
 
  • H. Dewa, T. Asaka, H. Hanaki, T. Kobayashi, A. Mizuno, S. Suzuki, T. Taniuchi, H. Tomizawa, K. Yanagida
    JASRI/SPring-8, Hyogo
  • J. Sasabe
    Hamamatsu Photonics K.K., Hamakita, Shizuoka
  • M. Uesaka
    UTNL, Ibaraki
  The paper describes the recent improvements of S-band RF-gun at SPring-8. The cavity of the gun is a single-cell pillbox, and the copper inner wall is used as a cathode. The electron beam from the cathode was accelerated up to 4.1 MeV at an electric field of 175 MV/m. For emittance compensation, two solenoid magnets were used. A 3m linac and a quadrupole scan emittance diagnostic were added after the RF-gun. The beam energy spread and beam emittance after the linac is presented. The beam emittance measured with quadrupole scan is compered to that measured with double slits just after the RF-gun. For high quantum efficiency, Cs2Te cathode was also tested. It is vacuum sealed in a cartridge-type electric tube and four tubes can be installed in a vacuum chamber behind the cavity. Although the quantum efficiency after RF conditioning for two hours to achieve 90MV/m was 3%, it decreased to 1% after the 28 hours RF conditioning.  
 
MOPKF047 Suppression of Stored Beam Oscillation Excited by Beam Injection gun, emittance, cathode, vacuum 414
 
  • T. Ohshima, N. Kumagai, M. Masaki, S. Matsui, H. Ohkuma, K. Soutome, M. Takao, H. Tanaka
    JASRI/SPring-8, Hyogo
  Top-up operation is scheduled from May 2004 at SPring-8. For this operation it is important that frequent beam injections should not excite the oscillation of stored beams. However, injection bump orbit was not closed perfectly and residual beam oscillations lead to increase of effective beam sizes by twice and three times in the horizontal and vertical direction respectively. We are trying to reduce these excited oscillations to less than one third of the usual beam sizes. For the suppression of horizontal one, we applied a novel scheme to reduce the effect due to the nonlinearity of sextupole magnets by adjusting the strength ratio of the sextupoles. The field similarity of bump magnets was also improved by replacing them with newly designed ones, where the effect of eddy current at the end plates was reduced. These countermeasures suppressed the horizontal oscillation by about one order. For the suppression of vertical one, the excitation mechanism has being investigated in detail. Presently the tilt angle adjustment of bump magnets reduced the vertical oscillation by one third. For further reduction of these oscillations, corrections with pulse-magnets is under investigation.  
 
MOPKF048 Injection Beam Loss at the SPring-8 Storage Ring injection, gun, emittance, cathode 417
 
  • M. Takao, T. Ohshima, S. Sasaki, J. Schimizu, K. Soutome, H. Tanaka
    JASRI/SPring-8, Hyogo
  Capture efficiency of injection beam is extremely important for top-up operation because open photon shutter permits the bremsstrahlung from lost particles to be transported to experimental floor. Furthermore, since the SPring-8 storage ring has many in-vacuum insertion devices with narrow gap, the demagnetization by the lost electron bombardment is also serious to the beam injection with gap closing. To clarify the loss mechanism of injected beam at the SPring-8 storage ring, we investigate the loss process under various conditions of the storage ring, and especially measure the dependence of injection loss rate on gaps of insertion devices. Comparing the measurements with simulations, we found that an injected particle with a large horizontal amplitude begins to oscillate in vertical direction through error magnetic field and eventually disappears at the vertical limit. It is also found that the low chromaticity of the storage ring is effective for the reduction of injection beam loss. In this paper, we report the loss mechanism of the injection beam of the SPring-8 storage ring and the possible improvements of the capture efficiency.  
 
MOPKF049 Design Study for a 205 MeV Energy Recovery Linac Test Facility at the KEK injection, linac, cathode, insertion 420
 
  • E.-S. Kim
    PAL, Pohang
  • K. Yokoya
    KEK, Ibaraki
  We present a lattice and beam dynmics analysis for a 200 MeV energy recovery linac test facility at the KEK. The test facility consists of a photocathode rf gun, a 5 MeV injector, a merger, 200 MeV superconducting linac, TBA sections and beam dump line. Beam parameters and optimal optics to relaize the energy recovery linac are described. Simulation results on emittance growth due to HOMs in the superconducting linac and coherent synchrotron radiation in the designed lattice are presented.  
 
MOPKF050 Current Heart-like Wiggler wiggler, injection, linac, cathode 423
 
  • V.I.R. Niculescu, G.R. Anda, F. Scarlat
    INFLPR, Bucharest - Magurele
  • V. Babin
    INOE, Bucharest
  • C. Stancu, A. Tudorache
    Bucharest University, Faculty of Physics, Bucharest-Magurele
  A new wiggler structure for free electron lasers is presented. Current hart-like wiggler produced magnetic fields which were spatially periodic. The current wiggler structure was in the shape of stacks of modified circle wires. The current had alternating directions. The magnetic field components for each wire present a C2 symmetry (for a model with 3 branches). The wiggler transverse cross - section in arbitrary units was given by the following expressions: x = R(d+sin(3j))cos(j) , y = R(d+sin(3j))sin(j) , z = constant, where d and R are the parameters. In cylindrical coordinates the Biot - Savart law was evaluated numerically. The magnetic field aspect was mainly transversal and also easily adjusted with the current . The versatility of this structure permits new geometrical forms and developments in the wiggler and wiggler design .  
 
MOPKF052 Design of an In Archromatic Superconducting Wiggler at NSRRC injection, wiggler, linac, cathode 425
 
  • C.-H. Chang, H.-H. Chen, T.-C. Fan, G.-Y. Hsiung, M.-H. Huang, C.-S. Hwang, F.-Y. Lin
    NSRRC, Hsinchu
  A 15-pole superconducting wiggler with period length of 6 cm is designed for National Synchrotron Research Center (NSRRC) in Taiwan. The compact superconducting wiggler will be installed near the second bending magnet of the triple bend achromat section in the 1.5 GeV storage ring. This wiggler magnet with maximum peak field of 3.2 T at pole gap width of 19 mm is operated in 4.2 K liquid helium vessel. A 5-pole prototype magnet is tested and measured to verify the magnetic field performance in the testing dewar. Furthermore, the cryogenic considerations and thermal analysis in the 4.2 K wiggler magnet and the 77 K vacuum chamber are also presented in this work.  
 
MOPKF053 Pulsed-wire Method of Field Measurement on Short Elliptically Polarized Undulator injection, wiggler, linac, cathode 428
 
  • T.-C. Fan, C.-S. Hwang, F.-Y. Lin
    NSRRC, Hsinchu
  With two sets of photo illuminator and detector, scientists already have applied pulsed-wire method to measure the magnetic field along two mutually perpendicular directions. Two-dimensional pulsed-wire method is useful for the test of elliptically polarlized undulator (EPU). We tried to use this method to observe the first integral and second integral fields of a short EPU in real time during the polarization tuning. We have taken care more details than the pulsed-wire measurement of planner undulators. The phase difference, the relative field strength along two direction as well as the precise centerline can be achieved.  
 
MOPKF054 Generation of Femtosecond Electron Pulses injection, wiggler, radiation, cathode 431
 
  • S. Rimjaem, V. Jinamoon, K. Kusoljariyakul, J. Saisut, C. Thongbai, T. Vilaithong
    FNRF, Chiang Mai
  • S. Chumphongphan
    Mae Fah Luang University, Chiang Rai
  • M.W. Rhodes, P. Wichaisirimongkol
    IST, Chiang Mai
  • H. Wiedemann
    SLAC/SSRL, Menlo Park, California
  Femtosecond electron pulses have become an interesting tool for basic and applied applications, especially in time-resolved experiments and dynamic studies of biomolecules. Intense, coherent radiation can be generated in a broad far-infrared spectrum with intensities, which are many orders of magnitude higher than conventional sources including synchrotron radiation sources. At the Fast Neutron Research Facility (FNRF), Chiangmai University (Thailand), the SURIYA project has been established with the aim to produce femtosecond pulses utilizing a combination of a S-band thermionic rf-gun and an alpha-magnet as the magnetic bunch compressor. A specially designed rf-gun has been constructed to obtain the optimum beam characteristics for best bunch compression. Simulation results show that the bunch lengths as short as 50 fs rms can be expected at the experimental station. This rf- gun, an alpha-magnet and a 20 MeV linac with beam transport system were installed and are being commissioned to generate femtosecond electron bunches. To measure the bunch length of the electron pulses, a Michelson interferometer will be used to observe the spectrum of coherent FIR transition radiation via optical autocorrelation. The main results of numerical simulations and experimental results will be discussed in this paper.  
 
MOPKF055 A Study of CSR Induced Microbunching Using Numerical Simulations injection, wiggler, bunching, cathode 434
 
  • M.A. Bowler, H.L. Owen
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  Microbunching due to Coherent Synchrotron Radiation (CSR) has been predicted for high density bunches and has been 'observed' using numerical simulations by the code ELEGANT of M. Borland, which includes a 1D model of CSR. However, there is currently a debate as to whether this micro-bunching is a real physical effect or is a numerical artefact, possibly introduced by having to use macro-particles to model the electrons. In particular, the amplitude of the micro-bunching diminishes as the number of macroparticles increases, but the question remains open as to whether the amplitude converges to zero or a finite value. The micro-bunching produced by ELEGANT is being studied as a function of the numerical parameters of the code and also as a function of the range of bunch parameters and bending magnet strengths of relevance to the 180 degree bending arcs required for the proposed 4GLS at Daresbury Laboratory. Calculations with up to 2 million macroparticles have been carried out on a Linux workstation using gaussian bunches of FWHM of 2psec and charge of 1 nC, and show the existence of microbunching at the end of a 180 degree arc containing 5 TBA cells with magnet strengths of 0.5T. Further investigation of this problem is required.  
 
TUPKF031 Non-resonant Accelerating System at the KEK-PS Booster positron, focusing, plasma, linac 1027
 
  • S. Ninomiya, M. Muto, M. Toda
    KEK, Ibaraki
  The non-resonant accelerating system for the KEK-PS booster accelerator has been constructed. The system has been operating since October 2003 without trouble. The accelerating gap in the system is loaded with magnetic cores of high permeability. The cores produce high resistive impedance at the gap. The power dissipated in the cores amounts to 50kW at 16kV accelerating voltage. It is removed by forced-air cooling system. At the last operation of the accelerator, with the help of new COD-correction system, the average beam intensity of the booster increased to 2.6E+12ppp, which is 30% higher than before.  
 
TUPKF032 COD Correction by Novel Back-leg at the KEK-PS Booster positron, focusing, plasma, linac 1030
 
  • S. Ninomiya, K. Satoh, H. Someya, M. Toda
    KEK, Ibaraki
  The COD correction is performed by using new driving system of back-leg windings. Two back-leg coils of the separate magnets are connected to make a closed circuit in which the induced voltages of the two magnets have opposite phases to each other. When the current source is inserted into the closed loop, the current drives the two magnets with opposite polarities. If the pair of magnets is properly selected, the current effectively corrects the orbit distortion. The selection rule of the pair is as follows; one is the magnet at the maximum distortion and the second magnet is that separated with the betatron phase of -90deg. The correction system at the KEK-PS Booster reduced the COD to less than 1/5 of that without correction, and increased the capture efficiency. The average beam intensity of our Booster is increased from 2E+12 to 2.6E+12ppp.  
 
TUPKF033 Cryogenic Performance of the Prototype Cryomodule for ADS Superconducting LINAC positron, focusing, plasma, beamloading 1033
 
  • N. Ohuchi, E. Kako, S. Noguchi, T. Shishido, K. Tsuchiya
    KEK, Ibaraki
  • N. Akaoka, H. Kobayashi, N. Ouchi, T. Ueno
    JAERI/LINAC, Ibaraki-ken
  • T. Fukano
    Nippon Sanso Corporation, Tokyo
  • H. Hara, M. Matsuoka, K. Sennyu
    MHI, Kobe
  A prottype cryomodule containing two 9-cell superconducting cavities of b=0.725 and f=972MHz is being constructed under the collaboration of Japan Atomic Energy Research Institute (JAERI) and High Energy Accelerator Research Organization (KEK) on the development of superconducting LINAC for Accelerator Driven System (ADS). Cryogenic performances of the cryomodule and 2K He-system will be reported.  
 
TUPKF034 Low Output-Impedance RF System for 2nd Harmonic Cavity in the ISIS Synchrotron positron, focusing, plasma, impedance 1036
 
  • T. Oki, S. Fukumoto, Y. Irie, M. Muto, S. Takano, I. Yamane
    KEK, Ibaraki
  • R.G. Bendall, I.S.K. Gardner, M.G. Glover, J. Hirst, D. Jenkins, A. Morris, S. Stoneham, J.W.G. Thomason, T. Western
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
  • J.C. Dooling, D. Horan, R. Kustom, M.E. Middendorf, G. Pile
    ANL, Argonne, Illinois
  In the ISIS facility based at Rutherford Appleton Laboratory (RAL) in the UK, second target station project was funded, which requires to increase the current intensity by 1.5-times (300 micro-A). Four 2nd harmonic RF cavities will be installed in the ISIS synchrotron in order to increase the trapping efficiency, and to mitigate the space charge detuning. A very low output-impedance RF system for the 2nd harmonic cavity has been developed by the collaboration between RAL, Argonne National Laboratory (US) and KEK (Japan). The system comprises the 240 kW triode as a final amplifier with plate-to-grid feedback path. The measured output-impedance was less than 30 ohms over the frequency range of 2.7 - 6.2 MHz, which agreed well with calculations. High power test was also performed under frequency swept mode at 50 Hz repetition. The operation was almost stable, and more than 12 kVpp was obtained as maximum. The voltage gain of the final amplifier was 25 - 30, which decreased gradually with frequency due to decreasing input-impedance of triode. The beam test is planned at ISIS in near future.  
 
TUPKF037 Multi-harmonic RF Acceleration System for a Medical Proton Synchrotron positron, focusing, plasma, impedance 1045
 
  • K. Saito, M. Katane, K. Kobayashi, K. Masui, K. Moriyama, H. Nishiuchi, H. Sakurabata, H. Satomi
    Hitachi, Ltd., Power & Industrial Systems R&D Laboratory, Ibaraki-ken
  We have developed an RF accelerating system for medical proton synchrotron. The RF cavity is a tuning-free wideband type, loaded with FINEMET cores, which is driven by a solid-state RF power amplifier with operation frequency range between 1MHz and 10MHz. Multi-harmonic RF acceleration scheme has been realized with the RF control system, to reduce beam loss by space-charge effect in low energy region. The original techniques for high-speed digital signal processing and high-precision RF signal processing have been applied, in order to fulfill feedback control of the frequency, phase and amplitude of the second and third harmonic RF signals as well as the fundamental one.  
 
TUPKF038 Reduced Length Designs of 500 MHz Damped Cavity Using SiC Microwave Absorber positron, focusing, plasma, impedance 1048
 
  • T. Koseki
    RIKEN/RARF/BPEL, Saitama
  • M. Izawa, S. Sakanaka, T. Takahashi, K. Umemori
    KEK, Ibaraki
  We present a new 500 MHz HOM (Higher-Order Modes) damped cavity for high brilliance synchrotron radiation sources. The design is based on the damped cavity, which is operated at the Photon Factory storage ring in KEK. The PF cavity has a large hole beam duct (140 mm in diameter), a part of which is made of a silicon carbide (SiC) microwave absorber. The new cavity, proposed in this paper, has parallel-plate radial transmission lines on the beam duct instead of the SiC beam duct. The outer end of the radial line is terminated by SiC absorbers. The HOMs, extracted from the center part of the cavity through the beam duct, propagate in the radial line and are dissipated in the absorber. The accelerating mode is not affected by the radial line damper since the frequency is sufficiently below the cutoff of the 140-mm beam duct. In this paper, optimized design of the radial line damper and damping properties for HOMs are described in detail.  
 
TUPKF039 The Experiences of Operation and Performance about the 500 MHz CW Klystrons at the PLS Storage Ring positron, focusing, plasma, impedance 1051
 
  • J.S. Yang, M.-H. Chun, Y.J. Han, S.-H. Nam, I.H. Yu
    PAL, Pohang
  There are four RF stations to supply the energy to electron at the storage ring of the Pohang Light Source(PLS). From the beginning of the operation of RF system, 500MHz 60kW(CW) klystrons have been operated. As the operation time of the tubes are increased, their performances are decreased. Therefore three 60kW tubes were replaced with the same model and two 75kW klystrons were replaced with 60 kW klystrons so far. Nowadays two 75 kW and two 60 kW klystrons are operated in the RF system of PLS. Our experiences of the klystron operation and their general performance are described in this paper.  
 
TUPKF041 Quasi-optic RF Power Transmission Line from a FEM Oscillator to the Model of the CLIC Accelerating Structure positron, focusing, plasma, impedance 1054
 
  • A. Kaminsky, A.V. Elzhov, E.A. Perelstein, N.V. Pilyar, T.V. Rukoyatkina, S. Sedykh, A.P. Sergeev, A. Sidorov
    JINR, Dubna, Moscow Region
  • N.S. Ginzburg, S.V. Kuzikov, N.Yu. Peskov, M.I. Petelin, A. Sergeev, N.I. Zaitsev
    IAP/RAS, Nizhny Novgorod
  Experimental investigation of a copper resonator lifetime under multiple action of 30 GHz power pulses is now carried out by the collaboration of CLIC team (CERN), FEM group of JINR (Dubna) and IAP RAS (Nizhny Novgorod). A quasi-optic two-mirror transmission line is used between the FEM oscillator and test cavity. An oversized FEM output waveguide based on the wavebeam transformation (Talbot effect) provides the optimal transverse distribution of the radiation, eliminates the output window breakdown and decrease the influence of the reflected wave on the FEM oscillator regime.  
 
TUPKF048 Studies of Electron Multipacting in CESR Type Rectangular Waveguide Couplers positron, focusing, plasma, impedance 1057
 
  • P. Goudket, M. Dykes
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • S.A. Belomestnykh, R. Geng
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  • R.G. Carter
    Microwave Research Group, Lancaster University, Lancaster
  • H. Padamsee
    Cornell University, Ithaca, New York
  The latest results from an experimental waveguide section, as well as simulations from a model of electron multipacting using the MAGIC PIC code, are discussed. Tests were carried out on a new waveguide section that included enhanced diagnostics and the possibility of changing surface materials and temperature. Those tests evaluated grooves, ridges and surface coatings, such as TiN and a TiZrV NEG coating, as methods of multipactor suppression. The conclusion remains that the most effective method to achieve complete multipactor suppression remains the application of a static magnetic bias of approximately 10G. The experiments also provided good data sets that can be used to verify the accuracy of simulations. Simulations of the waveguide multipacting have been carried out and have offered better understanding of electronic behaviour.  
 
TUPKF049 Combining Cavity for RF Power Sources: Computer Simulation and Low Power Model positron, focusing, plasma, impedance 1060
 
  • E. Wooldridge, S.C. Appleton, B. Todd
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  A combining cavity for RF power sources has been investigated as a way of saving space, in comparison to waveguides, and as a way of combining power with graceful degradation if one or more component were to fail. The cavity has been investigated as the maximum power output of an Inductive Output Tube (IOT) for CW is 80KW at 500MHz and a proposed output of 20KW at 1.3GHz and most RF systems for particle accelerators require much more than this. Although 1.3GHz klystrons do exist they are vastly more expensive to purchase and maintain. Also the down time could be minimised to minutes in the even of a single IOT failure where as a klystron has a minimum downtime of several days in the event of a failure. Initially the cavity and its inputs were simulated in CSTs? Microwave studio. After optimising the cavity to ensure the minimum reflection at the input ports and maximum transmission at the output port, a low power model was then created from aluminium. Signal generators were used to power the model and a network analyser was used to check the output. The model was used to compare the results gained from the computer simulation and to obtain results from asymmetric positioning of the ports, which was not possible in the simulation.  
 
TUPKF050 Triggers for RF Breakdown positron, focusing, plasma, impedance 1063
 
  • J. Norem, Z. Insepov
    ANL, Argonne, Illinois
  We outline a model of breakdown in rf cavities. Breakdown can be triggered by two mechanisms, one is fracture of the surface due to the tensile stress produced by the electric field, the second is Ohmic heating at grain boundaries and defects at very high current densities. We show how this model follows from measurements of local electric fields using electron field emission, and show how the model applies to the operating conditions of a variety of rf structures. This model may have some relevance to SCRF and DC structures.  
 
TUPKF055 Space-charge-limited Magnetron Injection Guns for Gyroklystrons positron, focusing, plasma, impedance 1072
 
  • W. Lawson
    Maryland University, College Park, Maryland
  We present the results of several space-charge-limited (SCL) magnetron injection gun (MIG) designs which are intended for use with a 500 kV, 500 A gyroklystron with accelerator applications. The design performances are compared to that of a temperature-limited (TL) gun that was constructed for the same application. The SCL designs yield similar values for beam quality, namely an axial velocity spread under 3% for an average perpendicular-to-parallel velocity ratio of 1.5. The peak electric fields and the cathode loadings of the SCL designs are somewhat higher than for the TL design. Three designs are described in this paper. In the first design the space-charge limit is achieved by recessing the emitter into the cathode. The other two designs have control electrodes to which a voltage can be applied to change the beam current independently of the beam voltage. One of these designs can accept a bias sufficiently high to cut off the current completely, so that a DC power supply with pulsed grid operation is possible. Details of all designs as well as a discussion of the advantages and disadvantages of the SCL designs as compared to the TL design will be given.  
 
TUPKF056 Multipacting in Crossed RF Fields near Cavity Equator positron, focusing, plasma, impedance 1075
 
  • V.D. Shemelin
    Cornell University, Ithaca, New York
  Electric and magnetic fields near the cavity equator are presented in a form of expansions up to the third power of coordinates. Comparisons with numerical calculations made with the SLANS code for the TESLA and other cavity cells, as well as with the analytical solution for a spherical cavity are done. These fields are used for solution of equations of motion. It appears that for description of motion, the only main terms of the expansion are essential, but the value of coefficients for the electric field components depend on details of magnetic field behavior on the boundary. Equations of motion are solved for electrons moving in crossed RF fields near the cavity equator. Based on the analysis of these equations, general features of this kind of multipacting are obtained. Results are compared with simulations and experimental data. The "experimental" formulas for multipacting zones are explained and their dependence on the cavity geometries is shown. Developed approach allows evaluation of multipacting in a cavity without simulations but after an analysis of fields in the equatorial region. The fields can be computed by any code used for cavity calculation.  
 
TUPKF058 Test Results for the New 201.25 MHz Tetrode Power Amplifier at LANSCE positron, focusing, plasma, impedance 1078
 
  • J.T.M. Lyles, S. Archuletta, J. Davis, L. Lopez, G. Roybal
    LANL/LANSCE, Los Alamos, New Mexico
  A new RF amplifier has been constructed for use as the intermediate power amplifier stage for the 201.25 MHz Alvarez DTL at LANSCE. It is part of a larger upgrade to replace the entire RF plant with a new generation of components. The new RF power system under development will enable increased peak power with higher duty factor. The first tank requires up to 400 kW of RF power. This can be satisfied using the TH781 tetrode in a THALES cavity amplifier. The same stage will be also used to drive a TH628 Diacrode? final power amplifier for each of the three remaining DTL tanks. In this application, it will only be required to deliver approximately 150 kW of peak power. Details of the system design, layout for DTL 1, and test results will be presented.  
 
TUPKF059 Simulation of Dark Currents in X-band Accelerator Structures positron, focusing, plasma, impedance 1081
 
  • K.L.F. Bane, V.A. Dolgashev, G.V. Stupakov
    SLAC, Menlo Park, California
  In high gradient accelerator structures, such as those used in the main linac of the GLC/NLC, electrons are emitted spontaneously from the structure walls and then move under the influence of the rf fields. In this report we study the behavior of this "dark current" in X-band accelerator structures using a simple particle tracking program and also the particle-in-cell program MAGIC. We address questions such as what is the sensitivity to emission parameters, what fraction of dark current is trapped and reaches to the end of a structure, and what are the temporal, spatial, and spectral distributions of dark current as functions of accelerating gradient.  
 
TUPKF061 The SPEAR3 RF System positron, focusing, plasma, impedance 1084
 
  • P.A. McIntosh, S. Allison, P. Bellomo, S. Hill, V. Pacak, S. Park, J.J. Sebek, D.W. Sprehn
    SLAC, Menlo Park, California
  SPEAR2 was upgraded in 2003, to a new 3rd Generation Light Source (3GLS) enabling users to take better advantage of almost 100x higher brightness and flux density over its predecessor SPEAR2. As part of the upgrade, the SPEAR2 RF system has been re-vamped from its original configuration of one 200 kW klystron feeding a single 358.5 MHz, 5-cell aluminum cavity; to a 1.2 MW klystron feeding four 476.3 MHz, HOM damped copper cavities. The system installation was completed in late November 2003 and the required accelerating voltage of 3.2 MV (800 kV/cavity) was very rapidly achieved soon after. This paper details the SPEAR3 RF system configuration and its new operating requirements, highlighting its installation and subsequent successful operation.  
 
TUPKF062 PEP-II RF System Operation and Performance positron, focusing, plasma, impedance 1087
 
  • P.A. McIntosh, J. Browne, J.E. Dusatko, J.D. Fox, W.C. Ross, D. Teytelman, D. Van Winkle
    SLAC, Menlo Park, California
  The Low Energy Ring (LER) and High Energy Ring (HER) RF systems have operated now on PEP-II since July 1998 and have assisted in breaking all design luminosity records back in June 2002. Luminosity on PEP-II has steadily increased since then as a consequence of larger e+ and e- beam currents being accumulated. This has meant that the RF systems have inevitably been driven harder, not only to achieve these higher stored beam currents, but also to reliably keep the beams circulating whilst at the same time minimizing the number of aborts due to RF system faults. This paper details the current PEP-II RF system configurations for both rings, as well as future upgrade plans spanning the next 3-5 years. Limitations of the current RF system configurations are presented, highlighting improvement projects which will target specific areas within the RF systems to ensure that adequate operating overheads are maintained and reliable operation is assured.  
 
TUPKF063 Current Status of the Next Linear Collider X-band Klystron Development Program positron, klystron, plasma, impedance 1090
 
  • D.W. Sprehn, G. Caryotakis, A.A. Haase, E.N. Jongewaard, C. Pearson
    SLAC, Menlo Park, California
  Klystrons capable of driving accelerator sections in the Next Linear Collider have been developed at SLAC during the last decade. In addition to fourteen 50 MW solenoid-focused devices and a 50 MW Periodic Permanent Magnet focused (PPM) klystron, a 500 kV 75 MW PPM klystron was tested in 1999 to 80 MW with 3-microsecond pulses, but very low duty. Subsequent 75 MW prototypes aimed for low-cost manufacture by employing reusable focusing structures external to the vacuum, similar to a solenoid electromagnet. During the PPM klystron development, several partners (CPI, EEV and Toshiba) have participated by constructing partial or complete PPM klystrons. After early failures during testing of the first two devices, SLAC has recently tested this design (XP3-3) to the full NLC specifications of 75 MW, 1.6 microseconds pulse length, and 120 Hz. This 14.4 kW operation came with a tube efficiency of 50%. The XP3 3 average and peak output power, together with the focusing method, arguably makes it the most advanced high power klystron ever built anywhere in the world. Design considerations and the latest testing results for these latest prototypes will be presented.  
 
TUPKF065 Comparison of Klystron and Inductive Output Tubes (IOT) Vacuum-electron Devices for RF Amplifier Service in Free-electron Laser positron, plasma, impedance, focusing 1093
 
  • A. Zolfaghari, P. MacGibbon, W. North
    MIT/BLAC, Middleton, Massachusetts
  The MIT X-Ray Laser project, conceived to produce output in the 0.3 to 100 nanometer range, is based on a super-conducting 4-GEV linear accelerator, using 24 multi-cavity cryo-modules, each with its own dedicated RF amplifier, operating at 1.3 GHz. The continuous output of each amplifier is nominally 15 kW, with an optional repetitive pulse-modulation mode of 0.1 second pulse duration at one pulse per second. Although there are no fundamental restraints which preclude the consideration of any RF amplifier type, including solid-state or conventional triode or tetrode, the most appropriate current technology includes the Klystron and the IOT (Inductive Output Tube), also known by the CPI trade-name, Klystrode. The mechanisms by which the devices convert DC input power into RF output power are discussed. The devices are then compared with regard to availability (developmental or off-the-shelf), conversion efficiency, means of pulse-modulation, RF power gain, phase and amplitude stability (pushing factors), and acquisition and life-cycle costs.  
 
TUPKF066 34 Ghz, 45 MW Pulsed Magnicon: First Results plasma, impedance, focusing, beamloading 1096
 
  • O.A. Nezhevenko, V.P. Yakovlev
    Omega-P, Inc., New Haven, Connecticut
  • J.L. Hirshfield, M.A. LaPointe
    Yale University, Physics Department, New Haven, CT
  A high efficiency, high power magnicon at 34.272 GHz has been designed and built as a microwave source to develop RF technology for a future multi-TeV electron-positron linear collider. To develop this technology, this new RF source is being perfected for necessary tests of accelerating structures, RF pulse compressors, RF components, and to determine limits of breakdown and metal fatigue. After preliminary RF conditioning of only about 200000 pulses, the magnicon produced an output power of 10.5 MW in 0.25 microsecond pulses, with a gain of 54 dB. Slotted line measurements confirmed that the output was monochromatic to within a margin of at least 30 dB.  
 
TUPKF067 High Power Magnicons at Decimeter Wavelength for Muon and Electron-Positron Colliders plasma, impedance, focusing, beamloading 1099
 
  • O.A. Nezhevenko, V.P. Yakovlev
    Omega-P, Inc., New Haven, Connecticut
  • J.L. Hirshfield
    Yale University, Physics Department, New Haven, CT
  The CLIC drive linac requires pulsed RF amplifiers with a power of 50 MW at 937 MHz. In turn the muon collider requires 100 MW, 800 MHz RF amplifiers for the final stages of acceleration. In this paper conceptual designs of magnicons for these applications are presented. In addition to the typical magnicon advantages in power and efficiency, the designs offers substantially shorter tube length compared to either single- or multiple-beam klystrons.  
 
TUPKF068 JLAB Hurricane Recovery plasma, impedance, focusing, beamloading 1102
 
  • A. Hutton, D. Arenius, F.J. Benesch, S. Chattopadhyay, E. Daly, V. Ganni, O. Garza, R. Kazimi, R. Lauze, L. Merminga, W. Merz, R. Nelson, W. Oren, M. Poelker, T. Powers, J.P. Preble, C. Reece, R.A. Rimmer, M. Spata, S. Suhring
    Jefferson Lab, Newport News, Virginia
  Hurricane Isabel, originally a Category 5 storm, arrived at Jefferson Lab on September 18 with winds of only 75 mph creating little direct damage to the infrastructure. However, electric power was lost for four days allowing the superconducting cryomodules to warm up and causing a total loss of the liquid helium. The subsequent recovery of the cryomodules and the impact of the considerable amount of opportunistic preventive maintenance provides important lessons for all accelerators complexes, not only those with superconducting elements. The details of how the recovery process was structured and the resulting improvement in accelerator availability will be discussed in detail.  
 
TUPKF072 Production and Performance of the CEBAF Upgrade Cryomodule Intermediate Prototypes plasma, impedance, focusing, beamloading 1105
 
  • A-M. Valente, E. Daly, J.R. Delayen, M. Drury, R. Hicks, C. Hovater, J. Mammosser, H.L. Phillips, T. Powers, J.P. Preble, C. Reece, R.A. Rimmer, H. Wang
    Jefferson Lab, Newport News, Virginia
  • C. Thomas-Madec
    SOLEIL, Gif-sur-Yvette
  We have installed two new cryomodules, one in the nuclear physics accelerator (CEBAF) and the other in the Free Electron Laser (FEL) of Jefferson Lab. The new cryomodules consist of 7-cell cavities with the original CEBAF cell shape and were designed to deliver gradients of 70 MV/module. Several significant design innovations were demonstrated in these cryomodules. This paper describes the production procedures, the performance characteristics of these cavities in vertical tests, results of tests in the new cryomodule test facility (CMTF) as well as the commissioning in the CEBAF tunnel and FEL. Performances and limitations after installation in the accelerators are discussed in this paper along with improvements proposed for future cryomodules.  
 
TUPKF074 Niobium Thin Film Cavity Deposition by ECR Plasma plasma, impedance, focusing, beamloading 1108
 
  • A-M. Valente, H.L. Phillips, H. Wang, A. Wu, G. Wu
    Jefferson Lab, Newport News, Virginia
  Nb/Cu technology for superconducting cavities has proven to be over the years a viable alternative to bulk niobium. Energetic vacuum deposition is a very unique alternative method to grow niobium thin film on copper. Single crystal growth of niobium on sapphire substrate has been achieved as well as good surface morphology of niobium on small copper samples. The design of a cavity deposition system is in development. This paper presents the exploratory studies of the influence of the deposition energy on the Nb thin film properties. Several possible venues to achieve Nb/Cu cavity deposition with this technique are also discussed along with the design of the cavity deposition setup under development.  
 
TUPKF075 Inductive Output Tubes for Particle Accelerators plasma, impedance, focusing, beamloading 1111
 
  • H.P. Bohlen
    CPI, Palo Alto, California
  • E. Davies, P. Krzeminski, Y. Li, R.N. Tornoe
    CPI/EIMAC, San Carlos, California
  The Inductive Output Tube (IOT) is not widely used as an RF power source in particle accelerators yet, but this is about to change rapidly. One reason for this change is the IOT's "coming of age": almost twenty years of successful operation in television transmitters have lead to high refinement of IOT technology and proven reliability. The other reason is the fitness of the IOT to especially meet accelerator requirements: high efficiency, no need for power back-off to achieve fast feed-back regulation, and the possibility to pulse the RF without using a high-voltage modulator. Two classes of IOTs are available so far for application in particle accelerators. One of them consists of UHF external-cavity devices, frequency-tunable and producing output power levels up to 80 kW CW. The second class has been developed only recently. These are L-band IOTs with internal output cavities for 1.3 and 1.5 GHz, respectively, featuring output power levels between 15 and 30 kW CW. Extensive computer simulations have lead to the conclusion that even higher-power IOTs, such as a 300 kW peak-power, long-pulse L-band tube, are feasible.  
 
TUPKF076 Large Scale Production of 805-MHz Pulsed Klystrons for SNS plasma, impedance, focusing, beamloading 1114
 
  • S. Lenci, E. Eisen
    CPI, Palo Alto, California
  The Spallation Neutron Source (SNS) is an accelerator-based neutron source being built in Oak Ridge, Tennessee, by the U.S. Department of Energy. The SNS will provide the most intense pulsed neutron beams in the world for scientific research and industrial development. CPI is supporting the effort by providing 81 pulsed klystrons for the super-conducting portion of the accelerator. The primary output power requirements are 550 kW peak, 49.5 kW average at 805 MHz, with an electron beam-to-rf conversion efficiency of 65% and an rf gain of 50 dB. Through January 2004, 47 units have been factory-tested. Performance specifications, computer model predictions, operating results, and production statistics will be presented.  
 
TUPKF077 Test Results for a 10-MW, L-band, Multiple-beam Klystron for TESLA plasma, impedance, focusing, beamloading 1117
 
  • E.L. Wright, A. Balkcum, H.P. Bohlen, M. Cattelino, L. Cox, E. Eisen, F. Friedlander, S. Lenci, A. Staprans, B. Stockwell, L. Zitelli
    CPI, Palo Alto, California
  • K. Eppley
    SAIC, Burlington, Massachusetts
  The VKL-8301 high-efficiency, multiple-beam klystron (MBK), has been developed for the DESY Tera Electron volt Superconducting Linear Accelerator (TESLA) in Hamburg, Germany. The first prototype is built and will be tested in March of 2004. The prototype has been designed for long-life operation by utilizing the benefits inherent in higher-order mode (HM) MBKs. The primary benefit of HM-MBKs is their ability to widely separate individual cathodes. One of the major obstacles to the success of this approach is the design of the off-axis electron beam focusing system, particularly when confined-flow focusing is desired. We will show simulated and measured data which demonstrates a solution to this problem. High power test results will also be shown.  
 
TUPKF078 High Current Superconducting Cavities at RHIC plasma, impedance, focusing, beamloading 1120
 
  • R. Calaga, I. Ben-Zvi, Y. Zhao
    BNL, Upton, Long Island, New York
  • J. Sekutowicz
    Jefferson Lab, Newport News, Virginia
  A five-cell high current superconducting cavity for the electron cooling project at RHIC is under fabrication. Higher order modes (HOMs), one of main limiting factors for high current energy-recovery operation, are under investigation. Calculations of HOMs using time-domain methods in Mafia will be discussed and compared to calculations in the frequecy domain. A possible motivation towards a 2x2 superstructure using the current five-cell design will be discussed and results from Mafia will be presented. Beam breakup thresholds determined from numerical codes for the five-cell cavity as well as the superstructure will also be presented.  
 
TUPKF079 A Low Noise RF Source for RHIC plasma, impedance, focusing, beamloading 1123
 
  • T. Hayes
    BNL, Upton, Long Island, New York
  The Relativistic Heavy Ion Collider requires a low noise rf source to ensure that beam lifetime during a store is not limited by the rf system. The beam is particularly sensitive to noise from power line harmonics. Additionally, the rf source must be flexible enough to handle the frequency jump required for rebucketing (transferring bunches from the acceleration to the storage rf systems). This paper will describe the design of a Direct Digital Synthesizer (DDS) based system that provides both the noise performance and the flexibility required.

Work performed under the auspices of the US Department of Energy

 
 
TUPKF080 Photoemission Properties of Lead plasma, impedance, laser, focusing 1126
 
  • J. Smedley, T. Srinivasan-Rao, J. Warren
    BNL, Upton, Long Island, New York
  • R.S. Lefferts, A.R. Lipski
    SBUNSL, Stony Brook, New York
  • J. Sekutowicz
    Jefferson Lab, Newport News, Virginia
  There is significant interest in the possibility of building a super-conducting injector for high average current accelerator applications. One candidate for such a cavity design is superconducting lead. Such an injector would be made considerably simpler if it could be designed to use lead as the photocathode, eliminating the need for Cesiated materials in the injector. In this paper we present a study of the photoemission properties of lead at several UV wavelengths, including a study of the damage threshold of electroplated lead under laser cleaning. A quantum efficiency in excess of 0.1% has been achieved for a laser cleaned, electroplated lead sample with a laser wavelength of 193 nm.  
 
TUPLT001 Beam Dynamics in 100 MeV S-Band Linac for CANDLE plasma, impedance, laser, focusing 1129
 
  • B. Grigoryan, V.M. Tsakanov
    CANDLE, Yerevan
  The report presents the results of the beam dynamics study in 100 MeV S-band linear accelerator foreseen as an injector for the CANDLE light source. An impact of the excited longitudinal and transverse wake fields on the particle energy spread and the beam transverse emittance are given.  
 
TUPLT002 The Small-gap Undulator Impedance Study plasma, impedance, laser, focusing 1132
 
  • M. Ivanyan, V.M. Tsakanov
    CANDLE, Yerevan
  The small gap undulator vacuum chamber resistive impedance model is developed. The vacuum chamber is considered as equal-radii tubes with the different wall materials (stainless steel "copper" stainless steel). The complete impedance was calculated as a sum of tubes and transitions impedances. The modal expansion method for transition impedance calculation is presented.  
 
TUPLT003 Transfer Matrices for the Coupled Space Charge Dominated Six-dimensional Particle Motion plasma, impedance, laser, focusing 1135
 
  • D. Kalantaryan, Y.L. Martirosyan
    CANDLE, Yerevan
  In this paper we present exact analytical solutions for the particle motion in the six-dimensional phase space taking into account the space charge forces of fully linear coupled beam. The transfer matrices for the typical elements of magnetic lattice, such as drifts, cavities, quadrupole and dipole magnets have been obtained. The symplectic transfer matrices are used to develop a tracking program for the coupled betatron and synchro-betatron motion that enables the simulation of the tilted beam effects in circular accelerators.  
 
TUPLT006 Simple Analytic Formulae for the Properties of Nonscaling FFAG Lattices plasma, impedance, laser, focusing 1138
 
  • S.R. Koscielniak
    TRIUMF, Vancouver
  • M.K. Craddock
    UBC & TRIUMF, Vancouver, British Columbia
  A hallmark of the "non-scaling" FFAG lattices recently proposed for neutrino factories and muon colliders is that a wide range of momentum is compacted into a narrow radial band; dL/L is of order 10-3 for dp/p of order unity. This property is associated with the use of F0D0 or FDF triplet lattices in which the F magnet provides a reverse bend. In this paper simple analytic formulae for key lattice properties, such as orbit displacement and path length as a function of momentum, are derived from thin-element models. These confirm the parabolic dependence of path-length on momentum observed with standard orbit codes, reveal the factors which should be adjusted to minimize its variation, and form a useful starting point for the thick-element design (for which analytic formulae are also presented). A key result is that optimized doublet, F0D0 and triplet cells of equal length and phase advance have equal path-length performance. Finally, in the context of a 10-20 GeV/c muon ring, the thin-element formulae are compared against lattice optical properties computed for thick-element systems; the discrepancies are small overall, and most discernible for the triplet lattices.  
 
TUPLT007 The CERN-SPL Chopper Concept and Final Layout plasma, impedance, laser, focusing 1141
 
  • F. Caspers, Y. Cuvet, J. Genest, M. Haase, M. Paoluzzi, A. Teixeira
    CERN, Geneva
  The fast chopper for the CERN SPL (Superconducting Proton Linac) consists of a double meander structure with a beta (v/c) value of 8 % printed on an alumina substrate for the deflecting plates. Each chopper unit is 50 cm long and housed in a quadrupole magnet surrounding the vacuum chamber. The deflecting plates are operated simultaneously in a dual mode, namely traveling wave mode for frequencies above about 10 MHz and as quasi electro-static deflectors below. The deflecting structures are water-cooled to handle heating from beam losses as well as from the deflecting signal. A detailed mechanical layout is presented including the tri-axial feeding and termination technique as well as a discussion of the drive amplifier  
 
TUPLT008 A Retrofit Technique for Kicker Beam-coupling Impedance Reduction plasma, laser, focusing, beamloading 1144
 
  • F. Caspers, E.H.R. Gaxiola, T. Kroyer, M. Timmins, J.A. Uythoven
    CERN, Geneva
  • S.S. Kurennoy
    LANL/LANSCE, Los Alamos, New Mexico
  The reduction of the impedance of operational ferrite kicker structures may be desirable in order to avoid rebuilding such a device. Often resistively coated ceramic plates or tubes are installed for this purpose but at the expense of available aperture. Ceramic U-shaped profiles with a resistive coating fitting between the ellipse of the beam and the rectangular kicker aperture have been used to significantly reduce the impedance of the magnet, while having a limited effect on the available physical aperture Details of this method, constraints, measurements and simulation results as well as practical aspects are presented and discussed.  
 
TUPLT009 Trajectory Correction Studies for the CNGS Proton Beam Line plasma, laser, focusing, beamloading 1147
 
  • M. Meddahi, W. Herr
    CERN, Geneva
  The performance of the proposed trajectory correction scheme for the CNGS proton beam line was checked with an advanced simulation program. It was first investigated whether the scheme will be sufficient, and if some correctors or monitors could be suppressed in order to reduce the cost. The correction scheme was in particular tested for the case of faulty correctors or monitors. Possible critical scenarios were identified, which may not be visible in a purely statistical analysis. This part of the analysis was largely based on the experience with trajectory and orbit correction problems encountered in the SPS and LEP. The simulation of the trajectory correction procedure was done using recently developed software.  
 
TUPLT010 Aperture and Stability Studies for the CNGS Proton Beam Line target, plasma, laser, focusing 1150
 
  • M. Meddahi, W. Herr
    CERN, Geneva
  The knowledge of the beam stability at the CNGS target is of great importance, both for the neutrino yield and for target rod resistance against non-symmetric beam impact. Therefore, simulating expected imperfections of the beam line elements and possible injection errors into the CNGS proton beam line, the beam spot stability at the target was investigated. Moreover, the mechanical aperture of the CNGS proton beam line was simulated and the results confirmed that the aperture is tight but sufficient.  
 
TUPLT015 The Bunch Compressor System for SIS18 at GSI target, plasma, laser, electron 1165
 
  • P. Hülsmann, G. Hutter, W. Vinzenz
    GSI, Darmstadt
  For bunch compression down to pulse durations of 50 ns, a dedicated rf system is under development for the SIS12/18 heavy ion synchrotron upgrade and will be described in this paper. Due to space restrictions in SIS12/18 the rf system consists of very short cavities which provide a very large voltage gradient (50 kV/m) at a very low frequency of approximately 800 kHz and rf final stages which provide a short rise time. The only possibilty to meet the requirements is the application of a cavity heavily inductively loaded by metallic alloy (MA) ring cores. This new rf system will be a prototype for the advanced acceleration and compression system needed in SIS100, which is the most important part for the proposed International Acceleration Facility at GSI. In order to gain experience with different MA ring core materials two of the four compressor cavities are loaded differently, which gives us an opportunity to learn the operational advantages of both materials. It is expected that the experimental results will support the final judgement for the future rf system in SIS100.  
 
TUPLT016 Improved Performance of the Heavy Ion Storage Ring ESR target, plasma, laser, electron 1168
 
  • M. Steck, K. Beckert, P. Beller, B. Franczak, B.  Franzke, F. Nolden
    GSI, Darmstadt
  The heavy ion storage ring ESR at GSI allows experiments with stable and radioactive heavy ions over a large range of energies. The energy range available for operation with completely stripped ions has recently been extended to energies as low as 3 MeV/u. Even for bare uranium such low energies can be provided by deceleration of the ions which are stripped to high charge states in a foil at energies of 300-400 MeV/u. After injection the beam is cooled and decelerated in an inverse synchrotron mode interspersed with electron cooling at an intermediate energy. At the lowest energy of 3 MeV/u some hundreds of thousands ions could be electron cooled after deceleration. At energies of 10-20 MeV/u physics experiments with stored and slowly extracted beam have been performed with some million decelerated cooled ions. The cooling of radioactive ions by a combination of stochastic pre-cooling and final electron cooling has been demonstrated. The hot fragment beam, which was injected at an energy of 400 MeV/u, was cooled in about 6 s to a quality useful for precision experiments.  
 
TUPLT017 Achievements of the High Current Beam Performance of the GSI Unilac target, plasma, laser, electron 1171
 
  • W. Barth, L. Dahl, J. Glatz, L. Groening, S.G. Richter, S. Yaramishev
    GSI, Darmstadt
  The present GSI-accelerator complex is foreseen to serve for the future synchrotron SIS100 as an injector for up to 1012 U28+ particles/sec. The High Current Injector of the Unilac was successfully commissioned five years ago. An increase of more than two orders of magnitude in particle number for the heaviest elements in the SIS had to be gained. Since that time many different ion species were accelerated in routine operation. In 2001 a physics experiment used 2×109 Uranium ions per spill. In order to meet this request the MEVVA ion source provided for the first time in routine operation a high intense Uranium beam. The main purpose for the machine development program during the last two years was the enhancement of the intensity for Uranium beams. Different hardware measures and a huge investigation program in all Unilac-sections resulted in an increase of the uranium intensity by a factor of 7. The paper will focus on the measurements of beam quality, as beam emittance and bunch structure for Megawatt-Uranium beams. Additionally the proposed medium- and long-term hardware measures will be described, which should gain in the required uranium intensity to fill the SIS up to the space charge limit.  
 
TUPLT018 Layout of the Storage Ring Complex of the International Accelerator Facility for Research with Ions and Antiprotons at GSI plasma, laser, focusing, beamloading 1174
 
  • P. Beller, K. Beckert, A. Dolinskii, B.  Franzke, F. Nolden, C. Peschke, M. Steck
    GSI, Darmstadt
  The storage ring complex of the new international accelerator facility consists of three different rings: the Collector Ring CR, the accumulator/decelerator ring RESR and the New Experimental Storage Ring NESR. The CR will serve for fast stochastic precooling of antiproton and rare isotope (RI) beams. Cooling time constants of about 100 ms for RI beams are envisaged. For experiments with RI beams the RESR serves as a decelerator ring. Precooled RI beams will be injected at 740 MeV/u and then decelerated to variable energies down to 100 MeV/u within about 1 s. The NESR will be the main instrument for nuclear and atomic physics. Besides experiments using an internal gas target, the NESR offers the possibility to collide circulating bunches of ions with electron bunches counter-propagating in a small 500 MeV electron storage ring. The physics program with antiprotons requires the accumulation of high intensity antiproton beams. The accumulation of 7×1010 antiprotons at 3 GeV per hour is foreseen. This will be accomplished by operating the RESR as an accumulator ring equipped with a stochastic cooling system. The NESR could then be used to decelerate antiprotons to 30 MeV.  
 
TUPLT019 Nonlinear Effects Studies for a Large Acceptance Collector Ring plasma, laser, focusing, beamloading 1177
 
  • A. Dolinskii, K. Beckert, P. Beller, B.  Franzke, F. Nolden, M. Steck
    GSI, Darmstadt
  A large acceptance collector ring (CR) is designed for fast cooling of rare isotope and antiproton beams, which will be used for nuclear physics experiments in the frame of the new international accelerator facility recently proposed at GSI. This contribution describes the linear and non-linear optimisation used to derive a lattice solution with good dynamic behaviour simultaneously meeting the demands for very fast stochastic cooling for two optical modes (for rare isotope and antiproton beams). Effects due to non-linear field contributions of the magnet field in dipoles and quadrupoles are very critical in this ring. Using a single particle dynamics approach, the major magnetic non-linearities of the CR are studied. We discuss the particle dynamics of the dipole and quadrupole fringe fields and the their influence on the dynamic aperture and on the tune. Additionally, the CR will be operated at the transition energy (isochronous mode) for time of flight (TOF) mass spectrometery of short-lived radioactive ions. For this mode a specific correction scheme is required to reach a high degree of isochronism over a large acceptance.  
 
TUPLT075 Improvements of SPring-8 Linac towards Top-up Operation laser, synchrotron, beamloading, antiproton 1327
 
  • S. Suzuki, T. Asaka, H. Dewa, H. Hanaki, T. Kobayashi, T. Masuda, A. Mizuno, T. Taniuchi, H. Tomizawa, K. Yanagida
    JASRI/SPring-8, Hyogo
  The top-up operation of the SPring-8 storage ring will start in May, 2004. In order to realize alternative injection into the booster synchrotron in the top-up operation and the NewSUBARU, an AC bending magnet replaced the DC bending magnet in the beam transport line to the booster synchrotron. This magnet operates at 1 Hz with a trapezoid current pattern. The 1-GeV electron beam goes at the bottom of the current pattern to the NewSUBARU or at the top of the pattern to the booster synchrotron. In order to obtain the higher reliability of the linac for the top-up operation, reinforcement of the beam monitor systems, further improvement of RF phase stability and upgrade of the control system were required. BPM?s has been newly installed in energy dispersion sections, and beam transport feedback control is in development. The phase variation in the RF system was reduced by the regulation of the gas pressure in the waveguide of the klystrons drive system. We re-engineered the VME systems to maximize availability of the linac operation considering its reliability, usability, expandability and flexibility.  
 
TUPLT076 Optimization of Sextupole Strengths in a Storage Ring for Top-up Operation sextupole, injection, laser, synchrotron 1330
 
  • H. Tanaka, T. Ohshima, K. Soutome, M. Takao, H. Takebe
    JASRI/SPring-8, Hyogo
  In top-up operation of a light source, electron or positron beams are frequently injected to keep the stored current constant. Closing an injection bump orbit is thus critically important not to disturb precise experiments. However, there are sextupole magnets inside the injection bump in the SPring-8 storage ring and the bump never closes all over the bump amplitude due to the sextupole nonlinearity. To solve the problem, we proposed a scheme based on minimum condition for the injection bump leakage. The scheme only restricts the sextupole strengths within the bump. Introduction of other sextupole families outside the bump can enlarge the dynamic aperture (DA) of the ring with keeping the minimum leakage. To find the best solution, we optimized the sextupole strengths changing the number of sextupole family as a parameter. The simulation shows that addition of two sextupole families sufficiently enlarges DA. Cabling of the sextupole magnets was partly changed in the summer 2003 and the effects of the strength optimization on the bump leakage, injection efficiency and beam lifetime has been investigated experimentally. We present the obtained results compared with the simulations.  
 
TUPLT077 R&D Status of the Fast Extraction Kicker Magnets for the KEK/JAERI 50 GeV Synchrotron sextupole, extraction, injection, proton 1333
 
  • Y. Shirakabe, Y. Arakaki, T. Kawakubo, Y. Mori, S. Murasugi, E. Nakamura, I. Sakai, M. Tomizawa
    KEK, Ibaraki
  The 50 GeV proton synchrotron composes the final stage of the high intensity proton accelerator complex now on construction at JAERI/Tokai site as a joint project by KEK and JAERI. In this ring, the proton beam is accelerated from 3 GeV to 50 GeV, and delivered to the experimental facilities through the fast and slow extraction lines. The distinctive feature of the fast extraction line is that the bipolar extraction function will be provided. In normal operations, the beam is extracted toward the inner side of the ring and transported to the facility for the long baseline neutrino oscillation experiment using the Super-Kamiokande detector. In case of emergency, for example, quenches of the superconducting magnets of the neutrino line or malfunctioning of the ring RF systems, the beam is extracted toward the outer side of the ring and sent directly to the abort line with a beam dump at the end. In the current kicker design, the bipolar function will be achieved by the Symmetric Blumlein PFN (SBPFN) system with two switches on both ends. The designed parameters of the fast extraction kicker magnets and the recent hardware R&D status will be described in this paper.  
 
TUPLT078 Study of Impedances and Instabilities in J-PARC sextupole, extraction, injection, laser 1336
 
  • T. Toyama, K. Ohmi
    KEK, Ibaraki
  • Y. Shobuda
    JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  J-PARC consists of two high intensity proton rings with energies of 3 GeV and 50 GeV. Longitudinal impedances and instabilities, which are caused by beam chamber, cavities, kicker magnets and others, are mainly discussed in this paper.  
 
TUPLT079 Opposite Field Septum Magnet System for the J-PARC 50GeV Ring Injection septum, sextupole, injection, laser 1339
 
  • I. Sakai, Y. Arakaki, K. Fan, Y. Mori, M. Muto, Y. Saitou, Y. Shirakabe, M. Tomizawa, M. Uota
    KEK, Ibaraki
  • K. Gotou, Y. Morigaki, A. Nishikawa, M. Takahashi
    IHI/Yokohama, Kanagawa
  • H. Mori, A. Tokuchi
    NICHICON, Shiga
  For the injection/extraction system of the high energy high intensity proton synchrotrons, high field wide aperture thin septum magnets are required. To solve these tight problems, new design concept of opposite-field septum magnet system has been invented. The same grade of opposite magnetic field is produced both inside and outside of the septum. The electromagnetic force and leakage flux around the septum conductor are cancelled out each other. The magnetic field of the circulating beam side is compensated by two sub-bending magnets set on the up-stream and down-stream of the opposite fields septum magnet. The beam-separation angle per magnet length is twice as large as normal septum magnet and the two sub-bending magnets also have a role to extend the injection/extraction angle. The newly developed method of the opposite field septum magnets system.is applied to the injection septum magnets for the J-PARC 50-GeV proton synchrotron to get the sufficient injection angle and clearance for low loss injection. The thin septum thickness and larger kick angle at the septum magnet can be obtained by the new system, which is applicable to many accelerators.  
 
TUPLT080 Design of the Beam Transportation Line from the Linac to the 3-GeV RCS for J-PARC septum, sextupole, linac, laser 1342
 
  • T. Ohkawa
    JAERI, Ibaraki-ken
  • M. Ikegami
    KEK, Ibaraki
  L3BT is beam transportation line from the linac to the 3-GeV RCS which is the part of the accelerators for the High-Intensity Proton Accelerator Facility Project, J-PARC. For the requirement of the beam loss minimization, the L3BT does not only connect the linac to the 3GeV RCS, but also modifies the linac beam to the acceptable shape for the 3-GeV RCS. The required beam parameters at the injection point of the RCS are momentum spread < ±0.1% (100%)and transverse emittance < 4pmm.mrad (99%). To achieve these beam qualities, the L3BT should have following functions: momentum compaction, halo scraping and beam diagnostics. In this paper, results of the design and beam simulation of the L3BT are presented.  
 
TUPLT081 Lattice Design of Large Acceptance FFAGs for the PRISM Project septum, sextupole, linac, laser 1345
 
  • A. Sato
    Osaka University, Osaka
  • S. Machida
    KEK, Ibaraki
  In order to realize a super muon beam that combines high-intensity, low-energy, narrow energy-spread and high purity, the PRISM project has been proposed. In this project, a FFAG ring is used as a phase rotator. In this paper, a method of designing the PRISM-FFAG lattice will be described. The PRISM-FFAG has to have both of large transverse acceptance and large momentum acceptance to achieve high intensity. Furthermore, long straight sections to install RF cavities are required to obtain a high surviving ratio of the muon. Therefore, the PRISM-FFAG requires its magnets to have large aperture and small opening angle. In such magnets, not only nonlinear effects but also magnetic fringing field are important to study the beam dynamics of FFAGs. Although using realistic 3D magnetic field maps made with programs such as TOSCA is the best solution to study the FFAG dynamics, it takes long time to make such field maps. On a design process of the PRISM-FFAG, quasi-realistic 3D magnetic field maps, which are calculated applying spline interpolation to POISSON 2D field, were used to study the beam dynamics. A program based on GEANT3.21 was used for particle tracking.  
 
TUPLT082 Generation of a Femtosecond Electron Beam for Nanoscience and Nanotechnology septum, sextupole, electron, gun 1348
 
  • J. Yang, T. Kozawa, S. Tagawa, Y. Yoshida
    ISIR, Osaka
  A new S-band femtosecond electron linear accelerator was developed in Osaka University for the study of radiation-induced ultrafast physical and chemical reactions in femtosecond time regions. The femtosecond electron accelerator was constructed with a laser driven photocathode RF gun, a linear accelerator (linac) and a magnetic pulse compressor. The RF gun was driven by a mode-locked Nd:YLF picosecond laser. The electron beam produced by the RF gun was accelerated in the linac with energy modulattion by adjusted the RF phase. The magnetic pulse compression, which was constructed with two 45o-bending magnets and four quadrupole magnets, is a technique to longitudinally focus a charged beam by rotating the phase space distribution in a magnetic field. The picosecond electron pulse, which was generated in the RF gun and accelerated in the linac with energy modulation, was compressed into femtosecond by adjusted the quadrupole magnetic fields. The femtosecond electron pulse is expected for the studies of ultrafast reactions in nano-space.  
 
TUPLT085 J-PARC Construction and its Linac Commissioning septum, sextupole, electron, gun 1351
 
  • Y. Yamazaki
    JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  The J-PARC(Japan Proton Accelerator Research Complex) accelerator is under construction in JAERI Tokai site. The beam commissioning will be started there by the end of 2006. Prior to this, the front end of the linac was beam-commissioned in 2003 at KEK. The negative hydrogen beam with a peak current of 30 mA was accelerated up to 20 MeV by the first tank of three DTL's following the 3-MeV RFQ linac. The 324-MHz DTL contains the electro quadrupole magnets with water-cooling channels specially fabricated by means of electroforming and wire-cutting technologies. The construction status of the J-PARC accelerator is also presented.  
 
TUPLT086 A 40MeV Electron Source with a Photocathode for X-ray Generation through Laser-compton Scattering septum, sextupole, gun, electron 1354
 
  • F. Sakai, N. Nakajyo, Y. Okada, T. Yanagida, M. Yorozu
    SHI, Tokyo
  .3 keV femtosecond X-ray generation through laser-Compton scattering with 14MeV electron source and a TW Ti:sapphire laser was achieved. In order to increase the X-ray energy up to 15 keV for some applications, e.g. protein crystallography, we modified the system to increase electron energy. Electron beams emitted from a S-band RF photocathode are accelerated up to 40MeV with two 1.5m standing-wave linacs. The beams are bended at 90 degree using an achromatic bending system, then focused with a triplet quadrupole-magnet to be interacted with laser pulses. The characteristics of electron beams, emittance, energy and energy dispersion, will be described.  
 
TUPLT087 Deflection Element for S-LSR septum, sextupole, gun, electron 1357
 
  • M. Ikegami, H. Fadil, A. Noda, T. Shirai, M. Tanabe, H. Tongu
    Kyoto ICR, Uji, Kyoto
  • T. Fujimoto, K. Noda, H. Ogawa, S. Shibuya, T. Takeuchi
    NIRS, Chiba-shi
  • M. Grieser
    MPI-K, Heidelberg
  • H. Okamoto
    HU/AdSM, Higashi-Hiroshima
  Main lattice of the ion storage and cooler ring, S-LSR is composed of 6 dipole and 12 quadrupole magnets. The maximum magnetic field, the radius of curvature and gap height are 0.95 T, 1050 mm and 70 mm, respectively. The field measurement of the dipole magnets has been completed with use of Hall-probe position controlled by driving mechanism composed of stepping motors and ball-screws. In order to cancel out the momentum dispersion, the radial electric field is superposed with the magnetic field. The radial electric field is applied by the electrodes installed into the vacuum vessel set inside the rather limited gap of the dipole magnet. Good field quality is to be realized with use of intermediate electrodes. In the present paper, the results of the magnetic field measurements are presented together with the design of the superposed electric field.  
 
TUPLT088 Beam Cooling at S-LSR septum, sextupole, gun, ion 1360
 
  • A. Noda, H. Fadil, S. Fujimoto, M. Ikegami, T. Shirai, M. Tanabe, H. Tongu
    Kyoto ICR, Uji, Kyoto
  • M. Grieser
    MPI-K, Heidelberg
  • I.N. Meshkov, E. Syresin
    JINR, Dubna, Moscow Region
  • K. Noda, T. Takeuchi
    NIRS, Chiba-shi
  • H. Okamoto, Y. Yuri
    HU/AdSM, Higashi-Hiroshima
  S-LSR is an ion accumulation and cooler ring with the circumference and maximum magnetic rigidity of 22.589 m and 1.0T.m, respectively. Electron beam cooling will be applied for laser-produced hot ion beam after phase rotation. Electron cooler for S-LSR is now under construction and the beam simulation is also going on. Laser cooling of Mg ion with low energy (35 keV) is also planned in 3-dimensional way with use of Synchro-Betatron coupling.so as to realize ultra cold beam. Cancellation of shear force due to orbit-length difference in the dipole section is to be studied with use of overlapping of the radial electric field inversely proportional to the curvature radius with the uniform vertical magnetic field. Possible experiments to approach to ultra-cold beam is also to be studied by computer simulation  
 
TUPLT089 Status of PEFP 3MeV RFQ Development septum, sextupole, gun, ion 1363
 
  • Y.-S. Cho, B.-H. Choi, S.-H. Han, J.-H. Jang, Y.H. Kim, H.-J. Kwon, C.-B. Shim
    KAERI, Daejon
  In the PEFP (Proton Engineering Frontier Project), a 350MHz, 3MeV RFQ (Radio Frequency Quadrupole) has been developed and tested. The tuning results showed that the resonant frequency is somewhat higher than 350MHz and other methods in addition to slug tuners should be used to tune the cavity correctly. To check the cavity characteristics, high power RF test has been done. The required peak RF power is 600kW and pulse width, repetition rate for initial test are 100 micro-s, 10Hz respectively. To solve the problems in PEFP RFQ, the upgrade design of 3MeV RFQ has been decided. The main concept of this upgrade design is constant vane voltage profile with the same length of RFQ. The other parameters (350MHz, 3MeV, 20mA) are the same with the previous RFQ. With constant vane voltage profile, fabrication of RFQ can be easier, and with the same mechanical dimension, other parts such as vacuum pumping station can be re-used. In this paper, the test results of the PEFP RFQ, and the details of beam dynamics design/engineering design of upgrade RFQ will be presented.  
 
TUPLT090 Combined Beam Dynamics Study of the RFQ and DTL for PEFP septum, sextupole, gun, proton 1366
 
  • J.-H. Jang, Y.-S. Cho, H.-J. Kwon
    KAERI, Daejon
  One of the goals of the Proton Engineering Frontier Project (PEFP) is to get 20 MeV proton beams of 20 mA through a 3 MeV RFQ and a 20 MeV DTL. This work is related to the combined beam dynamics study of the low energy proton accelerators in order to test the validity of the connection of the independently designed structures as well as to study the MEBT for beam transportation.  
 
TUPLT091 Fabrication Status of the PEFP 20 MeV DTL septum, sextupole, gun, ion 1369
 
  • M.-Y. Park, Y.-S. Cho, J.-H. Jang, Y.H. Kim, H.-J. Kwon
    KAERI, Daejon
  The PEFP (Proton Engineering Frontier Project) 20 MeV DTL have been constructed in KAERI site. The fabrication of the first tank is finished and the DT installation is in the process. We choose the pool-type electromagnets as the focusing magnet and 50 DTs will be installed on first tank. We tested the winding schemes of copper coils on the iron core and measured the magnetic field saturation.In this paper, the results of the tank fabrication and quadrupole magnet test are presented.  
 
TUPLT092 Optics and Magnet Design for Proton Beam Transport Line at PEFP septum, sextupole, proton, gun 1372
 
  • H.-S. Kang, H.S. Han, S.H. Jeong, Y.G. Jung, D.E. Kim, M. Kim, H.G. Lee, T.-Y. Lee, H.S. Suh
    PAL, Pohang
  The PEFP proton linac is designed to have two proton beam extraction lines at the 20-MeV and 100-MeV end, respectively. Each extraction line has 5 to 6 beamlines for proton beam users. The proton beam transport system for users? experiments will be prepared for this purpose. At the beginning, the beam optics for the proton beam transport system is designed with the TRACE code. The optics should be designed so as to meet the users? various requirements which might be to control the beam size and intensity at the beam target, and the timing of the proton beam. The magnet to distribute the proton beam to many beamlines is an AC magnet which has an AC frequency of 15 Hz, and is powered with a programmable AC power supply. In this paper, the result of the optics design will be presented and the magnet design will be described.  
 
TUPLT093 Tune Survey of Dynamic Apertures for High-brilliance Optics of the Pohang Light Source septum, sextupole, proton, gun 1375
 
  • E.-S. Kim
    PAL, Pohang
  The PLS storage ring is a 2.5 GeV light source and the dynamic apertures in a lattice for the low emittance in the ring have been investigated by a simulation method. The dynamic apertures that include effects of machine errors and insertion devices were obtained by a tune survey in the simulation. It was also shown that how large are the dynamic aperture compensated after corrections of a CODs. The betatron tune for the operation of the high-brilliance lattice are investigated based on the view point of dynamic apertures obtained from a tune survey.  
 
TUPLT095 Precision Field Mapping System for Cyclotron Magnet septum, sextupole, proton, gun 1378
 
  • K.-H. Park, Y.G. Jung, D.E. Kim, L.W.W. Lee
    PAL, Pohang
  • J.-S. Chai, Y.S. Kim
    KIRAMS, Seoul
  • B.-K. Kang, S.H. Shin, M. Yoon
    POSTECH, Pohang
  A 13 MeV cyclotron has been developed by KIRAMS for radio-isotopes production such as F-18 and O-15 for positron emission tomography(PET). To characterize the cyclotron magnet precisely, a Hall probe mapping system with very high precise positioning mechanism in the Cartesian coordinate has been developed. Hall probe assembly was translated in two dimensions by two stepping motors at both sides of the Hall-probe-carrier to keep synchronously rotation sharing one step-pulse source for x-axis and one motor for y-axis. The data acquisition time had reduced to 60 minutes in full mapping by 'flying' mode. The accuracy of the measurement system is better than during the entire mapping process. In this paper the magnetic field measurement system for the cyclotron magnet is described, and measurement results are presented.  
 
TUPLT096 RFQ Low Level RF System for the PEFP 100MeV Proton Linac septum, sextupole, gun, optics 1381
 
  • I.H. Yu, M.-H. Chun, K.M. Ha, Y.J. Han, W.H. Hwang, M.H. Jeong, H.-S. Kang, D.T. Kim, S.-C. Kim, I.-S. Park, J.S. Yang
    PAL, Pohang
  • Y.-S. Cho, K.T. Seol
    KAERI, Daejon
  The 100MeV Proton linear accelerator (Linac) for the PEFP (Proton Engineering Frontier Project) will include a 3MeV, 350MHz RFQ(Radio-Frequency Quadrupole) Linac. The RFQ accelerates a 20mA proton beam from 50keV to 3MeV. The low level RF system for RFQ provides field control. In addition to field control, it provides cavity resonance control. An accelerator electric field stability of ± 1% in amplitude and ± 1° in phase is required for the RF system. The low level RF system has been designed and is now being fabricated.  
 
TUPLT098 Vertical Beam Motion in the AGOR Cyclotron septum, sextupole, gun, optics 1384
 
  • M.A. Hofstee, S. Brandenburg, H. Post, W.K. van Asselt
    KVI, Groningen
  Large-scale vertical excursions have been observed in the AGOR cyclotron for light ionbeams at energies close to the focussing limit (E/A =200 Q/A MeV per nucleon). With increasing radius the beam gradually moves down out of the geometrical median plane by several mm, leading to internal beamlosses. It was concluded that this effect is caused by a vertical alignment error of the coils combined with the weak vertical focussing for the beams concerned. Moving the main coils by a total of 0.37 mm has significantly improved the situation at large radii, but results in internal beamlosses for certain beams at small radii due to a large upward excursion. A systematic study of the vertical beam dynamics as a function of beam particle and energy will be presented. Possible causes and solutions will be discussed.  
 
TUPLT099 A Kicker Pulse Power Supply with Low Jitter septum, sextupole, kicker, gun 1387
 
  • C.-S. Fann, J.-P. Chiou, S.Y. Hsu, K.-B. Liu
    NSRRC, Hsinchu
  The performance of kicker pulse power supplies is the main parameter to increase injection efficiency of storage ring that is an important issue for laboratory of synchrotron radiation research. The output current waveform of a kicker pulse power supply with low timing jitter is our goal for years that must satisfy the Top-Up mode injection requirement of NSRRC. In the past years kicker pulse power supplies of storage ring of NSRRC are immersed in isolation oil to sustain high voltage operational environment that led difficult to maintain, electronic component degrading and uneasy to tune parameters. Air-cooling and air-isolation is adopted in the new design structure for kicker pulse power supply system and an pre-trigger unit MA2709A is installed to trigger thyratron tube CX1536A, a kicker pulse power supply with low timing jitter 1~2ns(p-p) is obtained and could satisfy for Top-Up mode injection and maintenance is more easier than before.  
 
TUPLT102 Field Study of the 4T Superconducting Magnet for Rapid Cycling Heavy Ion Synchrotrons septum, kicker, gun, optics 1390
 
  • V.A. Mikhaylov, P.G. Akishin, A.V. Butenko, A.D. Kovalenko
    JINR, Dubna, Moscow Region
  The problem of the magnetic field optimization of a 4T dipole magnet with circular aperture of 100-110 mm for rapid cycling synchrotron is considered. A single layer low inductance coil made of hollow superconducting high current cable operating at 30 kA is used. The magnetic field ramp rate up to 4 T/s should be achievable. Mathematical method to minimize sextupole and higher order non-linearities to the tolerable values by variation of angular coil turn position is developed. The results of numerical simulation for 2D part magnetic field are presented. The further possibilities to improve the field quality for similar lattice magnets and their application for heavy ion synchrotrons and boosters are discussed.  
 
TUPLT103 Possibilities for Experiments with Rare Radioactive Ions in a Storage Ring Using Individual Injection septum, ion, gun, optics 1393
 
  • A.O. Sidorin, I.N. Meshkov, A.O. Sidorin, A. Smirnov, E. Syresin, G.V. Troubnikov
    JINR, Dubna, Moscow Region
  • T. Katayama
    CNS, Saitama
  • W. Mittig, P. Roussel-Chomaz
    GANIL, Caen
  A radioactive ion beam produced at a target bombarded with a primary beam has after a fragment separator a relatively large emittance and small production rate. For instance, typical flux of 132Sn isotope at the exit of fragment-separator is about 5×105 ions/s. Conventionally used scheme of the ion storage in a ring based on multitutrn injection and (or) RF stacking and stochastic cooling application can not provide a high storage rate at so pure intensity especially for short lived isotopes. In this report we discuss an alternative storage scheme which is oriented to the continuous ion beam from fragment separator at production rate of 104 ions/s or even less. It is based on the fact, that at low production rate the parameters of each particle can be measured individually with rather high accuracy. The particle trajectory can be individually corrected in a transfer channel from fragment separator to the storage ring using system of fast kickers. A fast kicker in the ring synchronized with a circulating bunch provides continuous injection of the ions. The scheme permits to store the ion number required for precise mass measurements and internal target experiment. A hope to obtain large luminosity of ion-electron collisions is related with a possibility of the ion beam crystallization at small particle number.  
 
TUPLT104 Particle Dynamics in the Low Energy Positron Toroidal Accumulator: First Experiments and Results ion, electron, gun, optics 1396
 
  • G.V. Troubnikov, V. Antropov, E. Boltushkin, V. Bykovsky, A.I. Ivanov, S. Ivashkevich, A. Kobets, I.I. Korotaev, V. Lohmatov, I.N. Meshkov, D. Monahov, V. Pavlov, R. Pivin, I.A. Seleznev, A.O. Sidorin, A. Smirnov, E. Syresin, S. Yakovenko
    JINR, Dubna, Moscow Region
  The project of Low Energy Particle Toroidal Accumulator (LEPTA) is dedicated to construction of a positron storage ring with electron cooling of positrons circulating in the ring. Such a peculiarity of the LEPTA enables it automatically to be a generator of positronium (Ps) atoms, which appear in recombination of positrons with cooling electrons inside the cooling section of the ring. The project has a few goals: to study electron and positron dynamics in the ring (particle motion in the horizontal and vertical planes are coupled contrary to of classic cycle accelerators), to set up first experiments with Ps in flight; Magnetic measurements of main LEPTA elements are performed. Several elements : kicker, injection system of electron beam, helical quadrupole, septum magnet are tested and expected design parameters were achieved for those elements. The investigations of electron beam dynamics are started. First results of experiments with circulating electron beam are presented and discussed in this article. Several beam diagnostic methods for studying of strong coupled motion of charged particles are proposed and tested.  
 
TUPLT105 Measurement of Activation Induced by an Argon Beam in a Copper Target at the SIS18 ion, electron, gun, optics 1399
 
  • A. Fertman, A. Golubev, M. Prokuronov, B.Y. Sharkov
    ITEP, Moscow
  • G. Fehrenbacher, R.W. Hasse, I. Hofmann, E. Mustafin, D. Schardt, K. Weyrich
    GSI, Darmstadt
  Results of the measurement of activation induced by Argon beam with energies of E=100,200,800 MeV/u in the copper target are presented. The densities of various radioactive isotopes are derived from the measurements. Long-time prediction of radioactivity and accumulated doses in the accelerator equipment is calculated.  
 
TUPLT106 New Developments of a Laser Ion Source for Ion Synchrotrons electron, gun, optics, proton 1402
 
  • S. Kondrashev, A. Balabaev, K. Konukov, B.Y. Sharkov, A. Shumshurov
    ITEP, Moscow
  • O. Camut, J. Chamings, H. Kugler, R. Scrivens
    CERN, Geneva
  • A. Charushin, K. Makarov, Y. Satov, Y. Smakovskii
    SRC RF TRINITI, Moscow region
  Laser Ion Sources (LIS) are well suited to filling synchrotron rings with highly charged ions of almost any element in a single turn injection mode. We report the first measurements of the LIS output parameters for Pb27+ ions generated by the new 100 J/1 Hz Master Oscillator - Power Amplifier CO2-laser system. A new LIS has been designed, built and tested at CERN, as an ion source for ITEP-TWAC accelerator/accumulator facility, and as a possible future source for an upgrade of the Large Hadron Collider (LHC) injector chain. The use of the LIS based on 100 J/1 Hz CO2-laser together with the new ion LINAC, as injector for ITEP-TWAC project is discussed.  
 
TUPLT111 RF Focusing of Low-Charge-to-Mass-Ratio Heavy-Ions in a Superconducting Linac electron, focusing, linac, gun 1405
 
  • E.S. Masunov, D.A. Efimov
    MEPhI, Moscow
  • P.N. Ostroumov
    ANL/Phys, Argonne, Illinois
  A post-accelerator of radioactive ions (RIB linac) must produce high-quality beams over the full mass range, including uranium, with high transmission and efficiency (P.N. Ostroumov and et al., Proc. of the PAC2001, p. 4080.). The initial section of the RIB linac is a low-charge-to-mass-ratio superconducting RF linac which will accelerate any ion with q/A>=1/66 to ~900 keV/u or higher. This section of the linac consists of many interdigital cavities operating at –20 degree synchronous phase and focusing can be provided by SC solenoids following each cavity. For the charge-to-mass ratio q/A=1/66 a proper focusing can be reached with the help of strong SC solenoid lenses with magnetic fields up to 15 T. These state-of-the-art solenoids are expensive. A possible lower cost alternative focusing method based on the combination of low-field SC solenoids and RF focusing is proposed and discussed in this paper.  
 
TUPLT112 Radiation Damage to the Elements of the Nuclotron-type Dipole of SIS100 electron, focusing, linac, gun 1408
 
  • E. Mustafin, G. Moritz, G. Walter
    GSI, Darmstadt
  • L. Latysheva, N. Sobolevskiy
    RAS/INR, Moscow
  Radiation damage to various elements of the Nuclotron-type dipole of SIS100 sensitive to irradiation was calculated. Among the elements of consideration were the superconducting cables, insulating materials, ceramic insertions and high-current by-pass diodes. The Monte-Carlo particle transport code SHIELD was used to simulate propagation of the lost ions and protons together with the products of nuclear interactions in the material of the elements. The results for the proton projectiles were cross-checked using the particle transport code MARS, and a good agreement between the codes were found. It was found that the lifetime of the organic materials under irradiation are much more restrictive limit for the tolerable level of beam particle losses than the danger of the quench events.  
 
TUPLT117 Test of Materials for the High Temperature Intense Neutron Target Converter focusing, linac, gun, ion 1413
 
  • K. Gubin, M. Avilov, S. Fadeev, A. Korchagin, A. Lavrukhin, P.V. Logatchev, P. Martyshkin, S.N. Morozov, S. Shiyankov
    BINP SB RAS, Novosibirsk
  • J. Esposito, L.B. Tecchio
    INFN/LNL, Legnaro, Padova
  Nowadays in LNL INFN (Italy) the project for gain and study of short-lived radioactive isotopes is in progress [1]. The intense neutron target is required for these goals. In BINP, Russia, the design of high temperature target cooled by radiation is proposed. Presented paper describes the results of preliminary test of materials for the target converter: MPG6-brand graphite, graphite material on the basis of 13C, boron carbide, glassy carbon. Test included the distributed heating over volume of samples with the electron beam up to conditions, simulating the converter working regime (heating power density up to 1300 W/cm2, temperature up to 20000C, temperature gradient up to 1000C/mm). Graphite materials show its adaptability under conditions specified.  
 
TUPLT118 Test of Construction for High Temperature Intense Neutron Target Prototype focusing, linac, gun, ion 1416
 
  • K. Gubin, M. Avilov, D. Bolkhovityanov, S. Fadeev, A. Lavrukhin, P.V. Logatchev, P. Martyshkin, A.A. Starostenko
    BINP SB RAS, Novosibirsk
  • O. Alyakrinsky, L.B. Tecchio
    INFN/LNL, Legnaro, Padova
  Within the framework of the creation of the high temperature intense neutron target prototype, the thermal tests of the preliminary design were done in BINP. Tests were aimed at experimental definition of temperature and heat flux distribution over the construction, heat transfer via the contact areas between materials selected, specifying the properties of these materials. This paper presents the experimental test results as well as the comparison of experimental data with the results of numerical simulation of the working regimes of the construction.  
 
TUPLT121 Compact Tandem Accelerator Based Neutron Source for the Medicine electron, focusing, linac, gun 1422
 
  • V.V. Shirokov, A.A. Babkin, P.V. Bykov, G.S. Kraynov, G. Silvestrov, Y. Tokarev
    BINP SB RAS, Novosibirsk
  • M.V. Bokhovko, O.E. Kononov, V.N. Kononov
    IPPE, Kaluga Region
  Status of original heavy hydrogen ion electrostatic accelerator-tandem is described. Potential electrodes with vacuum insulation organize tract for accelerating ion beam before and after gas stripper, located inside the high voltage electrode. There are no accelerating tubes in the tandem proposed. 20 kHz, 10 kW, 500 kV compact sectioned rectifier is a high voltage source. Both the geometry of neutron source and results of the rectifier testing are presented. Estimation of yield and space-energy distribution of neutron, as a result of nuclear reactions produced by heavy hydrogen ion in beryllium or carbon targets are given. Result of Monte-Carlo simulation of neutron and photon transferring for these sources of neutron is the distribution of the absorbed dose incide phantom. Result of the simulation are compared with result of the experiment. The possibility of use of this neutron source for the neutron or neutron capture therapy is discussed too.  
 
TUPLT124 DESIREE - A Double Electrostatic Storage Ring electron, focusing, linac, gun 1425
 
  • K.-G. Rensfelt, G. Andler, L. Bagge, M. Blom, H. Danared, A. Källberg, S. Leontein, L. Liljeby, P. Löfgren, A. Paal, A. Simonsson, Ö. Skeppstedt
    MSL, Stockholm
  • H. Cederquist, M. Larsson, H. Schmidt, K. Schmidt
    Stockholm University, Department of Physics, Stockholm
  The advantages of storage rings with only electrostatic elements were first demonstrated by ELISA in Aarhus and later in other places. At MSL and Fysikum at Stockholm University the ideas have been developed further in the Double Electrostatic Storage Ion Ring ExpEriment, DESIREE. Beams of negative and positive ions will be merged in a common straight section of the rings so that low energy collisions can be studied. Furthermore the rings will be cooled to 10 - 20 K in order to relax internal excitations in circulating molecules. A design report can be found at www.msl.se. The project is now (January 2004) almost fully financed and the final design work has recently been started. The paper will shortly review the physics programme and describe the status of the design work.  
 
TUPLT128 The Operation Modes of Kharkov X-ray Generator based on Compton Scattering NESTOR laser, focusing, linac, gun 1428
 
  • A.Y. Zelinsky, E.V. Bulyak, P. Gladkikh, I.M. Karnaukhov, A. Mytsykov, A.A. Shcherbakov
    NSC/KIPT, Kharkov
  • T.R. Tatchyn
    SLAC/SSRL, Menlo Park, California
  The results of theoretical and numerical considerations of linear Compton scattering are used to evaluate characteristics of X-rays produced by collision between a low emittance electron beam and intensive laser light in an X-rays generator NESTOR of NSC KIPT. Two main generation modes have been under consideration at preliminary NESTOR design. There are the operation mode for medicine 33.4 keV X-rays production using 43 Mev electron beam and Nd:YAG laser beam and higher energy X-rays production mode providing X-rays with energy up to 900 keV with 225 MeV electron beam and Nd:YAG laser beam. It is supposed to use an optical cavity for laser beam accumulation of about 2.6 m long and an interaction angle of about 30 in both operation modes. A few more operation modes provide possibility to expand operation range of NESTOR. Using interaction angle 100 and 1500 along with optical resonator 42 or 21 cm long and the second mode of laser light it is possible to produce X-rays in energy range from a few keV till 1.5 MeV. The intensity and spectral brightness of the X-rays is expected to be ~ 1013 phot/s and ~ 1013 phot/s/mm2/mrad2/0.01%BW respectively.  
 
TUPLT129 NESTOR Reference Orbit Correction focusing, linac, gun, optics 1431
 
  • V.A. Ivashchenko, P. Gladkikh, I.M. Karnaukhov, A. Mytsykov, V.I. Trotsenko, A.Y. Zelinsky
    NSC/KIPT, Kharkov
  It is known that intensity of scattered radiation in X-rays generators based on Compton scattering strongly depends on relative position of electron and laser beams. For this reason it is very important to have effective system of reference orbit correction and beam position control as well along whole ring as at the interaction point. In the paper the results of design and development of reference orbit correction system for compact storage ring NESTOR are presented. The total reference orbit correction will be carried out in vertical plane only. Correctors will be disposed on quadrupole lenses and will be provide reference orbit correction angle up to 0.10. The local correction at the interaction point will be provided with four correctors located at the interaction straight section. In the article results of calculations, layout of whole system, quadrupole lenses and pick-up station parameters and schemes are presented.  
 
TUPLT132 Investigation of Injection through Bending Magnet Fringe Fields in X-rays Source NESTOR linac, gun, optics, injection 1434
 
  • A. Mytsykov, P. Gladkikh, A.V. Rezaev, A.Y. Zelinsky
    NSC/KIPT, Kharkov
  In paper injection in the X-rays source NESTOR through fringe fields of a bending magnet is considered. The simulation of a motion of a beam of charged particles through 3-d fields of magnetic devices of the injection channel, which ones is located on a ring, are performed. The focusing properties of the injection channel are determined.  
 
TUPLT133 Test Results of Injector Based on Resonance System with Evanescent Oscillations linac, bunching, optics, injection 1437
 
  • S.A. Perezhogin, M.I. Ayzatskiy, E.Z. Biller, K. Kramarenko, V.A. Kushnir, V.V. Mytrochenko, Z.V. Zhiglo
    NSC/KIPT, Kharkov
  Report presents results of tune-up and tests of the compact electron S ? band injector consisting of the low-voltage diode electron gun and the bunching system based on the resonant system with the evanescent oscillation. In the considered bunching system electrical field increased from beam entrance to an exit of the buncher. The injector designed for bunching of electron beam with initial energy of 25 keV and pulse current of 300 mA and accelerating it to the energy of 1 MeV.  
 
TUPLT134 Lattice of NSC KIPT Compact Intense X-ray Generator NESTOR linac, electron, bunching, optics 1440
 
  • A.Y. Zelinsky, P. Gladkikh, I.M. Karnaukhov, V. Markov, A. Mytsykov, A.A. Shcherbakov
    NSC/KIPT, Kharkov
  The new generation of the intense X-rays sources based on low energy electron storage ring and Compton scattering of laser beam allows to produce X-rays with intensity up to 1014 phot/s. One of the main traits of a storage ring lattice for such generator type is using of magnetic elements with combined focusing functions such as bending magnets with quadrupole and sextupole field components. In combination with very low bending radius and dense magnetic elements setting along ring circumference it leads to increasing of 3D magnetic field effects on electron beam dynamics and can decrease generated radiation intensity drastically. For the reasons of very low electron beam size at the interaction point and strong focusing in a compact storage ring the questions of determination of accuracy of bending magnet is very important too. The paper is devoted to the description of lattice of NSC KIPT Compact X-ray generator NESTOR. The results of investigations of the effects of 3D magnetic field and harmonic compound due to manufacture errors of bending magnets, bending magnet and lenses edges on electron beam dynamics are presented.  
 
TUPLT136 Proton Beam Line for the ISIS Second Target Station target, linac, electron, bunching 1443
 
  • D.J. Adams
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  The ISIS facility, based at the Rutherford Appleton Laboratory in the UK, is an intense pulsed source of Muons and Neutrons used for condensed matter research. The accelerator facility delivers an 800 MeV proton beam of 2.5x1013 protons per pulse at 50 Hz. As part of the facility upgrade, which includes increasing the source intensity to 3.7x1013 protons per pulse using a dual harmonic RF system, it is planned to share the source with a second, 10 Hz, target station. A beam line supplying this target will extract from the existing target station beam line. Measurements and models characterising the optical functions around the extraction point of the existing line are discussed. The optical design, diagnostics and beam correction systems for second target station beam line are presented.  
 
WEPLT028 High-intensity and High-density Charge-exchange Injection Studies into the CERN PS Booster at Intermediate Energies injection, focusing, acceleration, bunching 1888
 
  • M. Martini
    CERN, Geneva
  • C.R. Prior
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  For the high brilliance LHC ultimate beam and the high intensity CNGS beam, single batch injections into the CERN Proton Synchrotron (PS) will be used to increase the overall machine intensity compared with the present double batch injections. Charge-exchange injection into the PS Booster with a new linac at intermediate energies is thus examined. A key parameter to consider is the energy dependence of beam incoherent tune shifts at injection. Increasing the linac energy from the present 50 MeV to 160 MeV should yield a safer tune shift. For each PS Booster ring, a charge-exchange injection scheme is envisaged inside a proper straight section, redesigned with new bends to make a local bump and using the existing fast bump magnets for horizontal phase-space painting. ACCSIM simulations for charge-exchange injection at 160 MeV have been investigated for both LHC and CNGS beams. After optimizing the parameters that are used for the space charge tracking routines, the results of the simulations agree well with expectations, signifying that the LHC ultimate and CNGS beams may be provided with single PS Booster batches within the required emittances. For assessment, simulation of injection at 50 MeV for the current LHC beam has been performed, yielding a fairly good agreement with measured performance. Concurrently, similar charge-exchange injection simulations have been carried out using an alternative programme developed at the Rutherford Appleton Laboratory.  
 
WEPLT029 Intensity Dependent Emittance Transfer Studies at the CERN Proton Synchrotron injection, focusing, acceleration, resonance 1891
 
  • E. Métral, C. Carli, M. Giovannozzi, M. Martini, R.R. Steerenberg
    CERN, Geneva
  • G. Franchetti, I. Hofmann
    GSI, Darmstadt
  • J. Qiang
    LBNL, Berkeley, California
  • R.D. Ryne
    LBNL/CBP, Berkeley, California
  An intensive study has been undertaken since the year 2002 to understand better the various high-intensity bottlenecks of the CERN Proton Synchrotron machine. One of these limitations comes from the so-called Montague resonance. High-intensity proton synchrotrons, having larger horizontal than vertical emittance, may suffer from this fourth-order coupling resonance driven by space charge only. In particular, such resonance may lead to emittance sharing and, possibly, beam loss due to vertical acceptance limitation. Experimental observations made in the 2002 and 2003 runs on the Montague resonance are presented in this paper and compared with 3D particle-in-cell simulation results and theoretical predictions.  
 
WEPLT030 Stability Diagrams for Landau Damping with Two-dimensional Betatron Tune Spread from Both Octupoles and Non-linear Space Charge applied to the LHC at Injection focusing, acceleration, resonance, bunching 1894
 
  • E. Métral, F. Ruggiero
    CERN, Geneva
  The joint effect of space-charge non-linearities and octupole lenses is discussed for the case of a quasi-parabolic transverse distribution of a monochromatic beam. The self-consistent non-linear space-charge tune shift corresponding to the above distribution function is first derived analytically. The exact dispersion relation is also given but not solved. Instead, noting that a good approximation of the non-linear space-charge tune shift is obtained considering only linear terms in the action variables, the dispersion relation is solved analytically in this approximate case. As expected, in the absence of external (octupolar) non-linearities, the result of Möhl and Schönauer is recovered: there is no stability region. In the absence of space charge, the stability diagrams of Berg and Ruggiero are also recovered. Finally, the new result is applied to the LHC at injection.  
 
WEPLT031 The LHC Access Control System focusing, acceleration, resonance, bunching 1897
 
  • P. Ninin, L. Scibile
    CERN, Geneva
  The LHC complex is divided into a number of zones with different levels of access controls. Inside the interlocked areas, the personnel protection is ensured by the LHC Access System. This system is made of two parts: the LHC Access Safety System and the LHC Access Control System. During machine operation, the LHC Access Safety System ensures the collective protection of the personnel against the hazards arising from the operation of the accelerator. By interlocking the LHC key safety elements, it will permit access to authorised personnel in the underground premises during the accelerator shutdowns and will deny access during accelerator operation. On the other hand, the LHC Access Control System, regulates the access to the accelerator and the numerous support systems. It allows a remote, local or automatic operation of the access control equipment that verifies the users? authorization, identifies them, locks and unlocks access control equipment and restricts the number of users working simultaneously in the interlocked areas. This paper introduces the main functions, architecture, technologies and methodology used to realise the LHC Access system.  
 
WEPLT033 The LHC Radiation Monitoring System for the Environment and Safety radiation, focusing, acceleration, resonance 1900
 
  • L. Scibile, D. Forkel-Wirth, H.G. Menzel, D. Perrin, G. Segura Millan, P. Vojtyla
    CERN, Geneva
  A state of the art radiation monitoring and alarm system is being implemented at CERN for the LHC. The RAdiation Monitoring System for the Environment and Safety (RAMSES) comprises about 350 monitors and provides ambient dose equivalent rates measured in the LHC underground areas as well as on the surface inside and outside the CERN perimeter. In addition, it monitors air and water released from the LHC installations. Although originally conceived for radiation protection only, RAMSES also integrates some conventional environmental measurements such as physical and chemical parameters of released water and levels of non-ionizing radiation in the environment. RAMSES generates local radiation warnings, local alarms as well as remote alarms on other monitored variables, which are transmitted to control rooms. It generates operational interlocks, allows remote supervision of all measured variables as well as data logging and safe, long-term archiving for off-line data analysis and reporting. Requirements of recent national and international regulations in combination with CERN's specific technical needs were translated into the RAMSES specifications. This paper outlines the scope, the organization, the main system performance and the system design.  
 
WEPLT035 Capture Loss of the LHC Beam in the CERN SPS radiation, focusing, acceleration, resonance 1903
 
  • E.N. Shaposhnikova, T. Bohl, T.P.R. Linnecar, J. Tuckmantel
    CERN, Geneva
  The matched voltage of the LHC beam at injection into the SPS is 750 kV. However, even with RF feedback and feed forward systems in operation, the relative particle losses on the flat bottom for nominal LHC parameters with this capture voltage can reach the 30% level. With voltages as high as 2 MV these losses are still around 15% pushing the intensity in the SPS injectors to the limit to obtain nominal intensity beam for the LHC. Beam losses grow with intensity and are always asymmetric in energy (lost particles are seen main in front of the batch). The asymmetry can be explained by the energy loss of particles due to the SPS impedance which is also responsible for a non-zero synchronous phase on the flat bottom leading to large gaps between buckets. In this paper the measurements of the dependence of particles loss on the beam and machine parameters are presented and discussed together with possible loss mechanisms.  
 
WEPLT036 Energy Loss of a Single Bunch in the CERN SPS radiation, focusing, acceleration, resonance 1906
 
  • E.N. Shaposhnikova, T. Bohl, T.P.R. Linnecar, J. Tuckmantel
    CERN, Geneva
  • A. Hofmann
    Honorary CERN Staff Member, Grand-Saconnex
  The dependence of energy loss on bunch length was determined experimentally for a single proton bunch in the SPS at 26 GeV/c. This was done from measurements of the synchronous phase as a function of intensity for different capture voltages. The results are compared with the expected dependence calculated from the resistive part of the SPS impedance below 1 GHz. Two impedance sources, the cavities of the 200 MHz RF system and the extraction kickers, give the main contributions to particle energy loss in very good agreement with experiment. The results obtained allow a better understanding of some mechanisms leading to capture loss of the high intensity LHC beam in the SPS.  
 
WEPLT037 A J2EE Solution for Technical Infrastructure Monitoring at CERN radiation, focusing, acceleration, resonance 1909
 
  • J. Stowisek, R.M. Martini, P. Sollander
    CERN, Geneva
  The Technical Infrastructure Monitoring project (TIM) will design and implement the future control system for CERN's technical infrastructure. The control system will be built using standard components including industrial PLCs, Java Enterprise Edition (J2EE) including Enterprise Java Beans and the Java Message Service and relational databases. This paper describes how these standard technologies are used to build a flexible, scalable, robust and reliable control system.  
 
WEPLT041 RF Amplitude Modulation to Suppress Longitudinal Coupled Bunch Instabilities in the SPS radiation, focusing, resonance, bunching 1921
 
  • E. Vogel, T. Bohl, U. Wehrle
    CERN, Geneva
  In the SPS, even after a considerable impedance reduction including the removal of all RF cavities used for lepton acceleration in the past, longitudinal coupled bunch instabilities develop with an LHC beam of about one fifth of the nominal bunch intensity. The nominal LHC beam is stabilised using both, the 800 MHz Landau damping cavities, in bunch shortening mode, and pre-emptive emittance blow-up. An alternative method to increase the synchrotron frequency spread and thus stabilise the beam is amplitude modulation of the accelerating RF voltage. This method might be especially suitable in accelerators without a higher harmonic RF system, as will be the case in LHC. The main results of recent studies using this method in the SPS and considerations about its use in LHC are presented.  
 
WEPLT042 Scheduling the Installation of the Large Hadron Collider radiation, focusing, resonance, bunching 1924
 
  • S. Weisz, K. Foraz, H. Gaillard, L. Lari
    CERN, Geneva
  The size and complexity of the LHC project at CERN calls for a strong co-ordination of all installation activities. The detailed installation planning has to take into account many constraints such as the component production rates, the installation contracts or the transport and handling requirements in a narrow tunnel with limited access points. The planning also needs to be flexible enough to cope with aleas that are unavoidable in such a large project that spans over many years. This paper describes the methodology followed by the team responsible for the planning and logistics in order to stay reactive to the actual progress of the installation and to keep optimizing the usage of resources.  
 
WEPLT043 Detecting Failures in Electrical Circuits Leading to Very Fast Beam Losses in the LHC radiation, focusing, resonance, bunching 1927
 
  • M. Zerlauth, B. Goddard, V. Kain, R. Schmidt
    CERN, Geneva
  Depending on the beam optics, failures in the magnet powering at locations with large beta functions could lead to very fast beam losses at the collimators, possibly within less than 10 turns. Beam loss monitors would normally detect such losses and trigger a beam dump. However, the available time for detection with beam loss monitors before reaching the damage level of a collimator might not be sufficient, in particular for beams with few particles in the tails. This has always been of concern and becomes even more relevant since very fast losses have been observed recently at HERA. In this paper, we present particle tracking studies for the LHC to identify failures on critical magnets. We propose a fast detection of such failures in the electrical circuit, either with highly precise hall probes for current measurement or measurements of the induced inductive voltage during the current decay. In combination with a small and simple interlock electronics such detection system can provide reliable and fast interlock signals for critical magnets in the LHC main ring but could also be used to monitor injection and extraction magnets. Depending on the properties of the electrical circuit an increase of the natural time constant of the current decay using a serial superconducting magnet is also considered.  
 
WEPLT052 A Method to Measure the Skew Quadrupole Strengths in the SIS-18 using Two BPMs focusing, bunching, impedance, optics 1954
 
  • F. Franchi, T. Beier, M. Kirk, M. Moritz, G. Rumolo
    GSI, Darmstadt
  • R. Tomas
    BNL, Upton, Long Island, New York
  In the SIS-18 of GSI a new set of skew quadrupoles has been installed to improve the multi-turn-injection. A new method based on the measurement of the resonance driving terms has been proposed to cross-check the nominal values and polarities of their gradients. Once a beam is transversely kicked, it experiences oscillations whose spectrum contains both the betatron tune line and secondary lines. The amplitude of each line is proportional to the strength of the multipoles, such as skew quadrupoles and sextupoles, present in the lattice. In this paper a recursive algorithm to derive the magnet strength from the spectral lines and the application of this method to the eight skew quadrupoles in the SIS-18 are presented.  
 
WEPLT068 Momentum Compaction Factor and Nonlinear Dispersion at the ANKA Storage Ring antiproton, damping, bunching, coupling 2002
 
  • A.-S. Müller, A. Ben Kalefa, I. Birkel, E. Huttel, M. Pont, F. Pérez
    FZK-ISS-ANKA, Karlsruhe
  The ANKA electron storage ring operates in the energy range from 0.5 to 2.5 GeV. In order to improve machine performance a precise modelling of linear and nonlinear optics is mandatory. Apart from higher order chromaticity also momentum compaction factor and dispersion have to be controlled. In this framework, the higher order momentum compaction factor has been determined exploiting the extraordinary precision of the resonant spin depolarisation method. Furthermore the nonlinear horizontal dispersion was measured as a function of the momentum deviation for different chromaticities. This paper discusses the experimental results and compares the findings to different simulations.  
 
WEPLT069 Investigation of Scraper Induced Wake Fields at ANKA antiproton, damping, bunching, coupling 2005
 
  • A.-S. Müller, I. Birkel, E. Huttel, M. Pont, F. Pérez
    FZK-ISS-ANKA, Karlsruhe
  • F. Zimmermann
    CERN, Geneva
  The ANKA synchrotron light source operates in the energy range from 0.5 to 2.5 GeV. Typical requirements for light sources include small beam sizes, large lifetimes and high currents to provide the highest possible photon flux. The understanding of impedance and instability related issues is very important in order to improve the machine performance, in particular when small aperture insertion devices are installed that require protection by a scraper. In the framework of an impedance survey the transverse and longitudinal wake fields induced by a vertical scraper have been measured and analysed. This paper reports the beam observations and compares them with the expectation.  
 
WEPLT070 Studies of Current Dependent Effects at ANKA antiproton, damping, bunching, coupling 2008
 
  • A.-S. Müller, I. Birkel, E. Huttel, M. Pont, F. Pérez
    FZK-ISS-ANKA, Karlsruhe
  • F. Zimmermann
    CERN, Geneva
  The ANKA electron storage ring is operated at energies between 0.5 and 2.5 GeV. A major requirement for a synchrotron light source, such as ANKA, is to achieve a high beam current. A multitude of mostly impedance related effects depend on either bunch or total beam current. This paper gives an overview over the various beam studies performed at ANKA in this context, specifically the observation of current dependent detuning, the dermination of the bunch length change with current from a measurement of the ratio between coherent and incoherent synchrotron tune and an assessment of the effective longitudinal loss factor from the current dependent horizontal closed orbit distortion.  
 
WEPLT071 Longitudinal Resonances and Emittance Growth Using QWR/HWR in a Linac antiproton, damping, coupling, focusing 2011
 
  • P. Bertrand
    GANIL, Caen
  In the frame of the SPIRAL II project at GANIL, we present an analytical approach allowing us to understand in a simple way the longitudinal behaviour of a beam , transmitted in bunching mode or accelerated in a Linac designed with QWR or HWR cavities. In particular, we make appear the strong relationship with the Henon map properties.  
 
WEPLT072 Preliminary Design of the RF Systems for the SPIRAL 2 SC Linac antiproton, damping, coupling, focusing 2014
 
  • M. Di Giacomo, B. Ducoudret, J.F. Leyge
    GANIL, Caen
  • J.F. Denis, M. Desmons, M. Luong, A. Mosnier
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  In the SPIRAL 2 Linac, a 5 mA, CW , Deuteron beam is accelerated up to 40 MeV, through a normal conducting RFQ and 26 independent-phase SC quarter wave resonators, working at 88,05 MHz. Tube and solid state amplifiers derived from the standard FM transmitter modules are used while a new digital control system has been designed for the feed-back and feed-forward control system. The paper presents the power and low level systems for both the normal and superconducting cavities and results of simulations of the RF system in operating conditions.  
 
WEPLT073 VDHL Design and Simulation of a Fast Beam Loss Interlock for TTF2 antiproton, damping, coupling, focusing 2017
 
  • A. Hamdi
    CEA/Saclay, Gif-sur-Yvette
  • M. Luong
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  • M. Werner
    DESY, Hamburg
  The TTF2 fast beam loss interlock provides different modes of protection. Based on the differential beam charge monitoring over a macropulse, a pulse slice or bunch-by-bunch, the signal processing time should be as short as the bunch repetition period (110 ns). The signal delivered by the toroid-like inductive current transformer always shows an envelope droop due to its self-inductance to resistance ratio. When the macropulse length is comparable to this ratio, the charge of each bunch must be derived from the difference of the top to the bottom level on the signal. This necessity combined to the various protection modes leads to a digital implementation. All the processing functionalities are designed with VHDL for a Xilinx FPGA. Because the interlock involves other control signals in addition to the toroid signal with specific shapes, which cannot be easily reproduced for the design validation before the TTF2 completion, VHDL provides meanwhile the possibility for an exhaustive validation of the system with a software test bench including all timing information.  
 
WEPLT075 Status Report on the Beam Dynamics Developments for the SPIRAL 2 Project antiproton, damping, coupling, focusing 2020
 
  • R. Duperrier, D. Uriot
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  • P. Bertrand, F. Varenne
    GANIL, Caen
  • J.-L. Biarrotte
    IPN, Orsay
  • J.-M. De Conto
    ISN, Grenoble
  • E. Froidefond
    LPSC, Grenoble
  • N. Pichoff
    CEA/DAM, Bruyères-le-Châtel
  The driver for the SPIRAL 2 project aims to accelerate a 5 mA D+ beam up to 20 A.MeV and a 1 mA beam for Q/A=1/3 up to 14.5 A.MeV. It operates in a continuous wave regime (cw), is designed for a maximum efficiency in the transmission of intense beams. Recent studies have led to change the reference design. The current design consists in an injector (ECR sources + LEBTs with the possibility to inject from several sources + a Radio Frequency Quadrupole) followed by a superconducting section based on an array of independently phased cavities where the transverse focalisation is performed by warm quadrupoles. This paper presents the beam dynamics studies associated to these new choices, the HEBT design and the fast chopping in the MEBT.  
 
WEPLT076 SPIRAL 2 RFQ Design antiproton, damping, coupling, focusing 2023
 
  • R. Ferdinand, G. Congretel, A. Curtoni, O.D. Delferriere, A. France, D.L. Leboeuf, J. Thinel, J.-C. Toussaint
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  • M. Di Giacomo
    GANIL, Caen
  The SPIRAL2 RFQ is designed to accelerate at 88MHz two kinds of charge-over-mass ratio, Q/A, particles. The proposed injector can accelerate a 5 mA deuteron beam (Q/A=1/2) or a 1 mA particles beam with q/A=1/3 up to 0.75 MeV/A. It is a CW machine which has to show stable operation, provide the request availability, have the minimum losses in order to minimize the activation constraints and show the best quality/cost ratio. It will be a 4-vane RFQ type, with a mechanical assembly, the global assumption being to build an RFQ without any brazing step. Extensive modelisation was made to ensure a good vane position under RF. A 1-m long hot model prototype is under construction in order to validate the manufacturing concept.  
 
WEPLT077 DESIGN OF A FULL-CUSTOM ACCURATE I-Q MODULATOR antiproton, damping, focusing, target 2026
 
  • M. Luong, M. Desmons
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  The I-Q modulator is a key component in a digital Low Level RF (LLRF) system for amplitude and phase feedbacks. Its residual errors in offset or gain have a strong impact on the dynamic and accuracy of the feedback loops. For some frequencies, commercial I-Q modulators are available on the market. But even in that case, these components are usually designed for broadband communication purposes, and their performances in term of residual errors may not fit the strict requirements on the final amplitude and phase loop stability. Since LLRF systems for accelerators are typically narrow-banded, i.e. limited to few MHz, it is possible to achieve a high directivity and a very accurate coupling for hybrids, and an excellent matching for all subcomponents in a fully custom design. This approach guarantees the lowest residual errors for an I-Q modulator. The principle for the design and the process for the optimization are presented in this paper.  
 
WEPLT078 The IFMIF High Energy Beam Transport Line antiproton, damping, focusing, target 2029
 
  • D. Uriot, R. Duperrier, J. Payet
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  The IFMIF project (International Fusion Materials Irradiation Facility) requests two linacs designed to accelerate 125 mA deuteron beams up to 40 MeV. The linac has to work in CW mode and uses one RFQ and 10 DTL tanks. After extraction and transport, the deuteron beams with strong internal space charge forces have to be bunched, accelerated and transported to target for the production of high neutron flux. This paper presents the high energy beam transport line which provides a flat rectangular beam profile on the liquid lithium target. Transverse uniformisation is obtained by using non-linear mutipole lenses (octupoles and duodecapoles). Beam dynamics with and without errors has been study.  
 
WEPLT079 Non Linear Beam Dynamics and Lifetime on the SOLEIL Storage Ring antiproton, damping, target, beamloading 2032
 
  • P. Brunelle, A. Loulergue, A. Nadji, L.S. Nadolski
    SOLEIL, Gif-sur-Yvette
  The incidence of several non-linear effects on the energy acceptance and beam lifetime has been investigated, using the BETA and TRACY II tracking codes. The effect of all magnets multipolar components has been checked on the working point (18.20; 10.30), especially the decapolar component induced by the H-corrector. The dipolar field, which is created by additional coils in the sextupoles, generates a significant decapolar component which, associated to the distributed dispersion, can reduce significantly the dynamic acceptance at large energy deviations. This effect depends on the natural closed orbit to be corrected: corrector strengths and cross talk between the different decapolar components. Moreover, the sensitivity to the number of correctors, used for correction, has been evaluated. The effect of insertions devices has also been studied, integrating field maps generated by the RADIA code into the tracking codes. With undulators, such as an in-vacuum U20 and an Apple II type HU80 (with different polarization modes), it was shown that the transverse field in-homogeneity and the focusing effects generating beta-beat can affect severely the energy acceptance and the beam lifetime because of resonance excitation.  
 
WEPLT080 Study of Resistive-wall Effects on SOLEIL antiproton, damping, target, beamloading 2035
 
  • R. Nagaoka
    SOLEIL, Gif-sur-Yvette
  The presence of low-gap chambers for insertion devices, along with a relatively small vertical gap of 25 mm chosen for the standard vacuum chambers, implies a significant influence of the resistive-wall on the beam in the future SOLEIL storage ring. A systematic approach was taken to quantify the net contribution by taking into account all local variations of the non-circular chamber cross-sections as well as beta functions. Low multibunch instability thresholds were found in both transverse planes, indicating the necessity of cures, by means of transverse feedback and/or chromaticity shifts. An effort was made to evaluate the effect of metallic coating, particularly that of NEG, which was adopted in all straight sections. The dependence on both resistivity and thickness of NEG was followed. It is found that, the NEG coating nearly doubles the reactive part of the impedance in the frequency range seen by the beam. Implication on the reduction of the transverse mode-coupling instability threshold is discussed. Incoherent tune shifts arising from the non-circular chamber cross-section were also evaluated, including a non-negligible NEG contribution in the short-range wakes.  
 
WEPLT081 Numerical Evaluation of Geometric Impedance for SOLEIL impedance, antiproton, damping, target 2038
 
  • R. Nagaoka
    SOLEIL, Gif-sur-Yvette
  Good knowledge and minimisation of the coupling impedance is of great importance for the future storage ring SOLEIL, envisaged to operate in both high current multibunch and high bunch intensity modes. Three-dimensional computations of the geometric impedance of various vacuum chamber components have been made with the code GdfidL, which allows parallel processing with a cluster of computers, rendering the computation with a small mesh size and a long integrated distance feasible. Many treated objects were found to exhibit large asymmetry in the two transverse planes, as well as resonant behaviour at high frequencies, both of which being non-straightforward to follow with the conventional analytical methods and 2-dimensional calculations. In particular, strongly trapped modes found for the flange impedance resulted in an unacceptably low vertical multibunch instability threshold, which urged a modification of the original cavity-like structure. The dependence of the dipole chamber impedance on the vertical slot size was followed to determine the optimal slot opening. Characteristics of the total broadband impedance obtained, along with relative contributions are also presented.  
 
WEPLT082 General Performances of the Injection Scheme into the SOLEIL Storage Ring impedance, injection, antiproton, damping 2041
 
  • M.-A. Tordeux, J. Da Silva, P. Feret, P. Gros, P. Lebasque, A. Mary
    SOLEIL, Gif-sur-Yvette
  The injection scheme of the electron beam into the Storage Ring of the SOLEIL synchrotron is presented. It corresponds to the new SOLEIL optics : 12 meter long straight section, 2.75 GeV energy, with in addition the requirement for top-up injection mode. Pulsed magnets are described, and in particular the passive septum magnet, the transverse position of which can be adjusted so as to optimise the Touschek beam Lifetime. Tracking of particles has been performed over a large number of turns, taking into account the magnet errors, the high chromaticities and the physical apertures all along the machine (limited vertical apertures due to low gap undulators). Statistical efficiency of the injection has been deduced. Specific requirements for top-up injection have been examined, such as the closure of the injection bump, the residual vertical field and the leakage fields from septa.  
 
WEPLT083 Coherent and Incoherent Tune Shifts Deduced from Impedance Modelling in the ESRF-Ring injection, antiproton, damping, target 2044
 
  • T.F. Günzel
    ESRF, Grenoble
  In single bunch the detuning of the transverse modes m=0,1 and -1 are calculated on the base of an impedance model contructed from element-wise wakefield calculation and the resistive wall impedance of the ESRF-ring. As the vacuum chambers of the ESRF storage ring have notably flat cross sections incoherent wake fields have an impact on the tune shifts as well as coherent wake fields. Compared to tune shift measurements in single bunch the calculated transverse mode detuning can explain half of the tune shift in the vertical plane and almost completely the tune shift in horizontal plane.  
 
WEPLT084 Experimental Frequency Maps for the ESRF Storage Ring injection, antiproton, damping, target 2047
 
  • Y. Papaphilippou, L. Farvacque, E. Plouviez, J.-L. Revol, A. Ropert
    ESRF, Grenoble
  • J. Laskar
    IMCCE, Paris
  • Ch. Skokos
    Academy of Athens, Athens
  Experimental frequency maps have already revealed many unknown characteristics of the ESRF storage ring non-linear dynamics. In the past year, several efforts were undertaken in order to establish this technique as an operational on-line tool. The acquisition time was significantly reduced by collecting data from a dedicated fast BPM system. The problem of beam decoherence was limited by establishing a method for accurate tune determination in a small number of turns, using the information from all the BPMs around the ring. The possibility to explore the off-momentum dynamics by exciting the beam, with synchronous transverse and longitudinal kicks was also investigated. Finally, measurements of resonance driving term amplitudes and phase advances were used to identify the efficiency of resonance corrections.  
 
WEPLT091 Frequency Map Analysis with the Insertion Devices at ELETTRA impedance, antiproton, damping, vacuum 2059
 
  • S. Di Mitri, L. Tosi
    ELETTRA, Basovizza, Trieste
  • L.G. Liu
    SSRF, Shanghai
  Frequency map analysis is a very efficient technique for the understanding of the resonances which may affect the stability of the electrons. Measurements correlated to simulations can provide a method to improve beam lifetime and injection efficiency that is particulary important in the case of top up operation. In this paper, the results of frequency map measurements and simulations for the ELETTRA storage ring are presented both for the bare lattice as well as for the case in which insertion devices are operational.  
 
WEPLT092 Equilibrium Longitudinal Distribution for Localized Regularized Inductive Wake impedance, antiproton, damping, vacuum 2062
 
  • S. Petracca, T. Demma
    U. Sannio, Benevento
  • K. Hirata
    GUAS, Kanagawa
  In a recent paper [*] we have shown that a localized wake assumption and the Gaussian approximation for the longitudinal beam distribution function can be used to understand the nature of the stationary solutions for the inductive wake, by comparison between the resulting map and the Haissinski equation, which rules the (less realistic) case of a uniformly distributed wake. In particular we showed the non-existence of solutions of Haissinski's equation when the inductive wake strength exceeds a certain threshold [**] to correspond to the onset of chaos in the map evolving the moments of the beam distribution from turn to turn. In this paper we use the same formalism to confirm that as noted in [**] for Haissinski's equation, a steady state solution for the longitudinal phase space distribution function always exists if a physically regularized inductive wake, which satisfies an obvious causality condition, is used.

* S. Petracca and Th. Demma, Proc. of the 2003 PAC, IEEE Press, New York, 2003, ISBN 0-7803-7739-9, p.2996.** Y. Shobuda and K. Hirata, Part. Accel. vol. 62, 165 (1999).

 
 
WEPLT093 Electromagnetic Fields of an Off-axis Bunch in a Circular Pipe with Finite Conductivity and Thickness - I impedance, antiproton, damping, vacuum 2065
 
  • S. Petracca, L. Cappetta, T. Demma
    U. Sannio, Benevento
  The electromagnetic field produced by a bunched beam in a circular pipe is usually computed under the assumption that the field penetration(skin depth) is far less than the wall thickness. Chao [*] gave a formula which exploits the wall thickness, but his result is restricted to the monopole term. Piwinski [**] treated the case of a metal coated ceramic wall, when the coating thickness is much smaller than the skin-depth, but his analysis is also limited to the monopole term.In this paper we solve the problem in full generality, by providing an exact (Green's functions) solution for the field of an off-axis point particle running at constant velocity in a circular pipe with finite wall conductivity and thickness.

* A.W. Chao, Phys. of Collective Beam Instab. in High En. Accel., Wiley,1993** S. Piwinski, DESY 1972/72

 
 
WEPLT094 Electromagnetic Fields of an Off-axis Bunched Beam in a Circular Pipe with Finite Conductivity and Thickness - II impedance, antiproton, damping, vacuum 2068
 
  • S. Petracca, L. Cappetta, T. Demma
    U. Sannio, Benevento
  • R.P. Croce
    Universita' degli Studi di Salerno, Dipartimento di Fisica E.R. Caianiello, Baronissi
  The general exact solution exploited [*] is applied, introducing suitable dimensionless parameters, and using appropriate asymptotic limiting forms, to compute the wake field multipoles for the different paradigm cases of LHC and DAPHNE.

* R. P. Croce, Th. Demma, S. Petracca "Electromagnetic Fields of an Off-axis Bunch in a Circular Pipe with Finite Conductivity and Thickness", these proceedings

 
 
WEPLT095 Modified Polarizabilities and Wall Impedance for Shielded Perforated Beam Pipes with General Shape antiproton, damping, vacuum, target 2071
 
  • S. Petracca, T. Demma
    U. Sannio, Benevento
  We extend previous results [*] concerning the modified polarizability of (electrically small) holes/slots in the wall of a circular beam liner surrounded by a coaxial circular tube to the most general liner and cold bore geometries. We obtain an equivalent wall impedance to describe the electromagnetic boundary conditions at perforated walls for this most general case, and use a general perturbational approach [**] for computing the pertinent longitudinal and transverse coupling impedances.

* R.L. Gluckstern, CERN SL 92-06 (AP), 1992, CERN SL 92-31 (AP), 1992; R.L. Gluckstern, B. Zotter, CERN SL 96-56 (AP), 1996.** S. Petracca, Part. Acc., {\bf 50}, 211, 1995; id., Phys. Rev. E, 60 (3),1999.

 
 
WEPLT097 Beam Loading in the RF Deflector of the CTF3 Delay Loop antiproton, damping, vacuum, target 2074
 
  • D. Alesini, F. Marcellini
    INFN/LNF, Frascati (Roma)
  In this paper we describe the impact of the beam loading in the RF deflectors on the transverse beam dynamics of the CTF3 Delay Loop. The general expression for the single passage wake field is obtained. A dedicated tracking code has been written to study the multi-bunch multi-turn effects on the transverse beam dynamics. A complete analysis for different machine parameters and injection errors is presented and discussed. The numerical simulations show that the beam emittance growth due to the wake field in the RF deflectors is small.  
 
WEPLT098 Experience with Long Term Operation with Demineralized Water Systems at DAFNE antiproton, damping, vacuum, target 2077
 
  • L. Pellegrino
    INFN/LNF, Frascati (Roma)
  During eight years operation of the Dafne water cooling system we coped with several critical situations and managed successfully specific upgrades to the demineralized water system. Here we revise critically the collected data and the experience gained in the field of copper corrosion and related water treatment.  
 
WEPLT101 On-line Mechanical Instabilities Measurements and Tuner Development in SC Low-beta Resonators electron, antiproton, plasma, vacuum 2083
 
  • A. Facco, E. Bissiato, S. Canella, D. Carlucci, M. Lollo, F. Scarpa, D. Zenere
    INFN/LNL, Legnaro, Padova
  The use of high-Q and small rf bandwidth superconducting quarter wave resonators made of bulk niobium put severe requirements to the helium bath pressure stability to avoid cavity detuning. This is not always possible, and cavity detuning caused by slow pressure changes must be precisely followed by the cavity tuner. The LNL philosophy is based on mechanical damping of cavity vibrations and mechanical tuning in feedback for slow frequency compensation. The old-fashioned tuners installed in the ALPI linac had significant performance limitations. To replace them, we have designed, constructed and tested a new tuner which integrates the LNL system and control with the TRIUMF, backlash-free tuner leverage design. The new tuner is designed to compensate pressure changes up to 100 mbar/minute with a precision of 0.5 Hz, and it will be installed in the ALPI resonators. An upgraded prototype for future applications includes a piezoelectric actuator for fast tuning. Tuner characteristics and first test results will be presented. This system is extendable to other low-beta cavity types like superconducting rfqs.  
 
WEPLT102 Electron Cooling Experiments at HIMAC Synchrotron antiproton, plasma, vacuum, target 2086
 
  • K. Noda, T. Furukawa, T. Honma, S. Shibuya, D. Tan, T. Uesugi
    NIRS, Chiba-shi
  • T. Iwashima
    AEC, Chiba
  • I.N. Meshkov, E. Syresin
    JINR, Dubna, Moscow Region
  • S. Ninomiya
    RCNP, Osaka
  In the HIMAC synchrotron, the electron cooling experiments have been carried out since 2000 in order to develop new technologies in heavy-ion therapy and related research. Among of them, especially, the cool-stacking method has been studied to increase the intensity of heavy ions such as Fe and Ni in order to study the risk estimation of the radiation exposure in space. The simulation was carried out in order to optimize the stacking intensity under various the injection periods. In addition, the beam heating by the RF-KO and the clearing the secondary ion in the cooler were applied to avoid the instability occurred when the beam density became high. We will report the experiment results.  
 
WEPLT103 Radiation Damage in Magnets for Undulators at Low Temperature radiation, antiproton, plasma, vacuum 2089
 
  • T. Bizen, X. Maréchal, T. Seike
    JASRI/SPring-8, Hyogo
  • Y. Asano
    JAERI/SPring-8, Hyogo
  • T. Hara, H. Kitamura, T. Tanaka
    RIKEN Spring-8 Harima, Hyogo
  • D.E. Kim, H.S. Lee
    PAL, Pohang
  Nd2Fe14B permanent magnets are used in many insertion devices for its good magnetic and mechanical properties. However, the radiation sensitivity of the magnets would be concern when they are used in a strong radiation environment. It is known that these magnets with very high coercivity show high resistance to radiation, though the substance for increasing the coercivity decrease the remanence. The coercivity and remanence of this magnet exhibit negative dependence against temperature, so it is expected to these magnets to show high remanence and high resistance to radiation at low temperature. The idea of using magnets at low temperature leads the new concept of the cryogenic undulators. In this report, the experimental results of the radiation damage of permanent magnets at low temperature are shown.  
 
WEPLT106 Growth and Suppression Time of an Ion-related Vertical Instability radiation, antiproton, plasma, octupole 2095
 
  • T. Miyajima, Y. Kobayashi, S. Nagahashi
    KEK, Ibaraki
  In the KEK Photon Factory electron storage ring, a vertical instability has been observed in a multi-bunch operation mode. The instability can be suppressed by octupole magnetic field in routine operation. Since the instability depends on a vacuum condition in the ring, it seems that it is an ion-related phenomenon. In order to study this instability, we measured the growth and the suppression time of it with the pulse octupole magnet system, which can produce the octupole field with rise and fall time of around 1.2msec. We obtained the result that the instability was grown slowly compared with to suppress it, and the growth time depended on the fill pattern of the bunch train and the beam current per bunch.  
 
WEPLT109 Simulation of Ep Instability for a Coasting Proton Beam in Circular Accelerators radiation, sextupole, antiproton, plasma 2104
 
  • K. Ohmi, T. Toyama
    KEK, Ibaraki
  • G. Rumolo
    GSI, Darmstadt
  ep instability is discussed for a coasting beam operation of J-PARC 50 GeV Main Ring. Our previous study (PAC2003) was focussed only ionization electron. We now take into account electrons created at the chamber wall due to proton loss and secondary emission with higher yield than ionization.  
 
WEPLT110 Specific Beam Dynamics in Super-bunch Acceleration radiation, sextupole, antiproton, plasma 2107
 
  • Y. Shimosaki, E. Nakamura, K. Takayama, T. Toyama
    KEK, Ibaraki
  • K. Horioka, M. Nakajima
    TIT, Yokohama
  • K. Koseki
    GUAS/AS, Ibaraki
  • K. Torikai
    Kyushu University, Fukuoka
  • M. Watanabe
    RIKEN, Saitama
  Proof-of-principle experiments on the induction synchrotron concept using the KEK 12-GeV PS makes progress, in which RF bunches and a super-bunch will be accelerated with a long step voltage generated in the induction accelerating gaps. In order to give a guide for super-bunch acceleration, the beam stabilities against a droop and a fluctuation of the accelerating voltage have been examined by using a simulation. The droop voltage gives an additional focusing or defocusing force in the longitudinal direction, which leads the mismatching beyond the transition energy. Furthermore, the extremely slow fluctuation of the accelerating voltage causes a lowest-order resonance near the transition. These induce a serious emittance blow-up in the longitudinal, so that the compensating manners will be presented. Moreover, the other issues such as head-tail instability and intra beam scattering will be discussed.  
 
WEPLT113 Development of New Hydrostatic Levelling Equipment for Large Next Generation Accelerator radiation, sextupole, antiproton, plasma 2110
 
  • S. Takeda
    KEK, Ibaraki
  The Hydrostatic Levelling Systems (HLS) are installed and commissioned in many laboratories. We have developed a new type hydrostatic levelling equipment for the large future accelerator. The designing points are as followings: (1) use of half filled water level sensor instead of the usual full filled level sensor, (2) the capacitive sensor is supported by an invar rod and (3) use of digitized signal transfer system. These three points are very important factor to apply the leveling system to large next generation accelerator in order to obtain good temperature stability and being free from the environmental electronic noises. We have obtained a typical resolution of the equipment as 0.3 micron-meter, though usual HLS shows the value ten times as much. We are going to show a detailed report about the system including data obtained.  
 
WEPLT114 Field Measurements in the AGS Warm Snake radiation, sextupole, antiproton, plasma 2113
 
  • J. Takano, M. Okamura
    RIKEN, Saitama
  • R. Alforque, R. Belkin, G. Ganetis, A.K. Jain, W.W. MacKay, T. Roser, R. Thomas, J. Tuozzolo
    BNL, Upton, Long Island, New York
  • T. Hattori
    RLNR, Tokyo
  A new warm snake has been produced for avoiding the transverse coupling resonance in the Alternating Gradient Synchrotron (AGS) at Brookhaven National Laboratory (BNL). The warm snake is the world?s first normal conducting helical dipole partial snake which has a double pitch structure to allow spin rotation with no net beam offset or deflection with a single magnet. The warm snake is 2.6m long, and has a field of 1.5 Tesla for a 9 degrees spin rotation. The pitches, current density, and shims were optimized by using OPERA_3D / TOSCA. The magnetic field harmonics have been measured using a system of 51 mm long, 34 mm radius tangential coils. The axial variation of the dipole field angle agrees very well with the calculations, indicating no significant construction errors. However, the measured transfer function shows a discrepancy of 4% which may be caused by BH-curve differences, deformation of the iron and packing factor of the laminations. To correct the beam trajectory the operating current was adjusted and shims were installed on the end plates. These optimization studies, and comparison with measurements, will be shown.  
 
THPKF024 A STATE-OF-THE-ART 3 GEV BOOSTER FOR ASP lattice, beamloading, beamlosses, impedance 2314
 
  • G. Georgsson, N. Hauge
    Danfysik A/S, Jyllinge
  • S.P. Møller
    ISA, Aarhus
  DANFYSIK A/S will build the full-energy booster for the Australian Synchrotron Project. The Booster will accelerate the beam from the injection energy of 100 MeV to a maximum of 3.0 GeV. The Booster shall accelerate either a single bunch or a bunch train up to 150 ns. The current accelerated to 3 GeV will be in excess of 0.5 and 5 mA for the two modes, respectively. The circumference of the Booster is 130.2 m, and the lattice will have four-fold super-symmetry with four straight sections for RF, injection, special diagnostics and extraction. The lattice is designed to have many cells with combined-function magnets (dipole, quadrupole and sextupole fields) in order to reach a very small emittance of around 30 nmrad. A small emittance is beneficial, in particular for top-up operation. Details of the lattice design and beam dynamics of the booster will be presented.  
 
THPKF025 Commissioning Report of the CLS Booster Synchrotron lattice, beamloading, beamlosses, impedance 2317
 
  • G. Georgsson
    Danfysik A/S, Jyllinge
  • L. Dallin
    CLS, Saskatoon, Saskatchewan
  • S.P. Møller
    ISA, Aarhus
  • L. Præstegaard
    Århus Sygehus, Århus
  A full energy booster is produced and taken into operation for the Canadian Light Source. The Booster accelerates the beam from the injection energy of 200 MeV to a maximum of 2.9GeV. The results of the commissioning and the characterized beam parameters are reported  
 
THPKF026 An Update on the SESAME Light Source beamloading, beamlosses, impedance, radiation 2320
 
  • D. Einfeld
    CELLS, Bellaterra (Cerdanyola del Vallès)
  • M. Attal, G. Vignola
    SESAME, Amman
  During the past three years, the SESAME machine design has been optimised gradually taking into consideration the users demand in the Middle East region. The earlier design concept was to upgrade BESSY I to an energy of 1GeV, now SESAME is a 2.5GeV 3rd generation light source. A recent design review has recommended changing the machine lattice and layout to give greater flexibility for future upgrading and modification, the longest possible beam lines and the longest possible insertion devices, all of that with the limitation of the space available for the machine within the building. By shifting the machine by 6m from the centre of the building (in one direction) it was possible to increase the circumference of the storage ring by 3.6m into 128.4m and beam lines with lengths of 37.7m achieved, while the longest beam line in the old design was only 33.1m, this also increased the total length of the beam lines from 378.2m in the old design into 391.0m. An outline of these optimisations with their influence on the machine output is presented here. Furthermore the beam dynamics, the design of the main components of the storage ring and the first set of beam lines will be discussed.  
 
THPKF030 Progress Report on the construction of SOLEIL beamloading, damping, beamlosses, linac 2332
 
  • J.-M. Filhol
    SOLEIL, Gif-sur-Yvette
  The construction of SOLEIL, the French new SR facility, was launched in Jan 2002. The construction of the building has started in Aug 2003 and will enable a progressive beneficial occupancy from summer 2004 onwards. It is foreseen to achieve the commissioning of the 100 MeV Linac by the end of 2004, of the 3 Hz Booster in spring 2005 and of the 2.75 GeV Storage Ring by the end of 2005. All the major components have been ordered and some have already been delivered : the Booster and SR dipole magnets, the Linac sections and the Booster RF cavity. Some innovative development have been initiated specifically for SOLEIL: A 352 MHz SC RF cavity, solid state RF amplifiers for the Booster (40 kW) and the Ring (2 x 190 kW), BPM digital electronics, Al NEG coated vacuum vessels for all straight parts of the ring, or electromagnetic undulators to provide high brilliance polarized light in the VUV range. In order to provide the best performances, significant attention was paid at each design stage (optics, magnets, BPM, vacuum and RF systems,..), involving a large effort of simulation, using 6D tracking codes, or evaluating in detail the contribution of each component to the machine impedance.

on behalf of the SOLEIL project team

 
 
THPKF032 Cleaning of Parastic Bunches in the ESRF Booster Synchrotron for Time Structure Modes of Operation beamloading, damping, beamlosses, linac 2338
 
  • E. Plouviez, N. Michel
    ESRF, Grenoble
  The ESRF injector booster accelerates electron bunches from 200 MeV to 6 GeV and inject them in a storage ring. It can accelerate a small number (1 to 5) of high charge bunches for the so called "time structure" filling mode operation of the SR. In this case we must avoid storing parasitic low charge bunches in the unused RF bucket of the SR. Until now this was achieved by a resonant knockout of these parasitic bunches on the beam stored in the SR. We have developed and implemented a system allowing the removal of these parasitic electrons during the acceleration in the booster, so that no extra cleaning is needed on the beam stored in the SR. This paper describes our setup and its key components, the tuning of the operating parameters of the system and presents the results achieved.  
 
THPKF033 Prospects for Long-term Lattice Upgrade at the ESRF beamloading, damping, beamlosses, linac 2341
 
  • A. Ropert, P. Elleaume, L. Farvacque, Y. Papaphilippou, T. Perron
    ESRF, Grenoble
  Twelve years after commissioning, the ESRF delivers routinely X-rays of brilliance, a factor hundred higher than the design target, to 45 beamlines. Further long-term improvements to the storage ring performance concern the reduction of the horizontal emittance leading to an increase of the brilliance and/or the increase of the number of beamlines from insertion device source points. In this paper, we review the different scenarios that can be envisaged with keeping untouched the existing tunnel and beamlines. Among them, the concept of the Double DBA structure that combines the reduction of emittance (a factor of 8) and the increase of the number of straight sections (64 instead of 32) looks the most attractive. Some of the challenging issues of such a scheme (squeezed space between magnets, innovative combined function magnets of unprecedented small aperture, small dynamic aperture) will be discussed.  
 
THPKF034 Design of a Photoneutron Source based on a 5 MeV Electron Linac target, electron, beamloading, damping 2344
 
  • L. Auditore, R.C. Barnà, D. De Pasquale, A. Trifirò, M. Trimarchi
    INFN & Messina University, S. Agata, Messina
  • A. Italiano
    INFN - Gruppo Messina, S. Agata, Messina
  A photoneutron source, based on a 5 MeV electron linac was designed by means of the MCNP simulation code. Although higher electron energies are required to produce acceptable neutron fluxes, the availability of a 5 MeV electron linac developed at the Dipartimento di Fisica (Università di Messina) has suggested this project, in sight of a future development and testing of the studied neutron source. Be and BeD2 targets were considered, whose neutron production was studied optimizing two sequential steps: the bremsstrahlung production in a suitable e-gamma converter and the (gamma,n) production in an properly designed photoneutron target-reflector-moderator system. As a result of a comparative study of different materials performances, a 0.88 mm-thick W layer was chosen as e-gamma converter. A natural graphite reflector was designed, surrounding the target, enhancing the neutron flux of two order of magnitude. The final neutron flux, at 50 cm from the photoneutron target, thermalized by a 12.2 cm-thick PE layer, was estimated to be 8.48E+07 n/cm2/sec/mA with Be target and 1.23E+08 n/cm2/sec/mA with BeD2 target.  
 
THPKF035 Design of the Super-SOR Light Source target, synchrotron, beamloading, damping 2347
 
  • N. Nakamura
    ISSP/SRL, Chiba
  The Super-SOR light source is a Japanese VUV and soft X-ray third-generation synchrotron radiation source, which is to be operated for nation-wide and world-wide users. The University of Tokyo has proposed to construct the facility in Kashiwa new campus and we have designed the light source intensively for more than two years. The light source consists of an electron storage ring, booster synchrotron and pre-injector linac. The 1.8-GeV storage ring has a circumference of about 280 m and 14 DBA cells with two 17-m and twelve 6.2-m long straight sections, which are used for twelve insertion devices and RF and injection systems. The booster synchrotron is compact, one third of the ring in circumference, and can achieve a low emittance of about 50 nmrad at 1.8 GeV. The 200-MeV linac is made up of S-band accelerating structures powered by two 50-MW klystrons and a SLED cavity and capable of changing the beam current widely in both single- and multi-bunch operation modes. These accelerators are designed so as to fully meet requirements for top-up injection. We describe the design of the Super-SOR accelerators here.

on behalf of the Super-SOR accelerator design group

 
 
THPKF036 Developments of the FZP Beam Profile Monitor target, beamloading, beamlosses, linac 2350
 
  • N. Nakamura, M. Fujisawa, H. Kudo, H. Sakai, K. Shinoe, H. Takaki, T. Tanaka
    ISSP/SRL, Chiba
  • H. Hayano, T. Muto
    KEK, Ibaraki
  A beam profile monitor based on two Fresnel Zone Plates (FZPs) has been developed at the KEK-ATF damping ring. This monitor can perform real-time imaging of the electron beam with an X-ray imaging optics and the synchrotron radiation and measure the horizontal and vertical beam sizes with a high spatial resolution. A clear electron-beam image with the vertical beam size less than 10 microns was already obtained in the early measurements [*]. Thereafter some of the optical elements, the crystal monochromator, X-ray CCD camera and FZP holders, were improved and an X-ray pinhole mask was installed between the two FZPs for reducing the background of X-rays passing through the MZP (the second FZP). Aberrations due to alignment errors of the FZPs were studied with an analytical approach and a ray-tracing method and vibrations of the optical elements were measured in order to estimate their effects on the system performance. In this paper, we will present developments of the beam profile monitor with results of some beam-size measurements.

* K. Iida et al., Nucl. Instrum. Methods A506, p.41-49 (2003); N. Nakamura et al., Proc. of PAC2003, p.530-532

 
 
THPKF037 Quasi-isochronus Operation at NewSUBARU target, beamloading, beamlosses, linac 2353
 
  • Y. Shoji, S.H. Hisao, T. Matsubara
    LASTI, Ako-gun, Hyogo
  Quasi-isochronus operation is one of the operation modes of NewSUBARU, a 1.5 GeV VUV storage ring. NewSUBARU has six invert bending magnets to control the momentum compaction factor. The aim of this research is to explore the extreme reduction of electron bunch length by reducing the linear momentum compaction factor. We experimentally reduced the momentum compaction factor from 0.0014 down to less than 10-5, keeping the beam in the ring. The second-order momentum compaction factor was adjusted to almost zero, while keeping the third-order momentum compaction factor positive. The ring was operated at 1.0 GeV. Using a streak camera, the shortest bunch length we observed was 4 ps FWHM. With such a low momentum compaction factor, we expect an energy spreading by betatron oscillation even at the extremely low beam current.  
 
THPKF038 Radiation Damage of Magnet Coils due to Synchrotron Radiation radiation, target, beamloading, beamlosses 2356
 
  • K. Tsumaki, S. Matsui, M. Oishi, T. Yorita
    JASRI/SPring-8, Hyogo
  • T. Shibata, T. Tateishi
    KOBELCO, Hyogo
  Radiation damage of the equipment in the SPring-8 storage ring tunnel has become a serious problem. In the storage ring, the unnecessary radiation from bending magnets is shielded by absorbers. The equipment around the absorbers was damaged by the scattered radiation from the absorbers. Last year, cooling water leaked from the rubber hose of magnets. It was due to the deterioration of rubber hose caused by synchrotron radiation. We measured the radiation distribution around the storage ring and found that the most high intensity spot was on the magnet coil near the absorbers. If the coils are damaged and the magnets do not work correctly, we need to shut down the storage ring to exchange the magnet coils. To avoid such a situation, we needed to clarify the relation between the radiation damage of the coils and the dose of radiation. We did an acceleration test of the radiation damage of magnet coils. The magnet coils were exposed to the radiation from the bending magnet directly. We observed the degree of damage with changing the doses of radiation. In this paper, we describe about these acceleration tests and test results.  
 
THPKF039 Study of Photo-cathode RF Gun for a High Brightness Electron Beam radiation, target, cathode, beamloading 2359
 
  • Y. Yamazaki
    JNC/OEC, Ibaraki-ken
  • S. Araki, H. Hayano, M. Kuriki, T. Muto, N. Terunuma, J. Urakawa
    KEK, Ibaraki
  • M.K. Fukuda, K. Hirano, M. Nomura, M. Takano
    NIRS, Chiba-shi
  We are going to develop a compact high-brightness electron beam system to adopt industrial and medical applications. A multi-bunch photo-cathode RF gun has been developed to generate 100 bunches beam with 2.8ns spacing and 5nC charge per bunch. We will report details of the development, especially photo-cathode production and emission characteristics from cathode by the laser.  
 
THPKF040 Development of a Femtosecond Pulse Radiolysis for Reaction Analysis in Nano-space target, cathode, laser, electron 2362
 
  • Y. Yoshida, T. Kozawa, S. Tagawa, J. Yang
    ISIR, Osaka
  A new femtosecond pulseradiolysis system was developed in Osaka University for the study of radiation-induced ultrafast physical and chemical reactions in femtosecond time regions. In the pulseradiolysis system, a femtosecond electron beam produced by a photocathode RF gun is used as an irradiation source, while a mode-locked Ti:Sapphire femtosecond laser was used as a probe light source. A time jitter between the electron pulse and the femtosecond laser was compensated by a jitter compensation technique used a femtosecond streak camera. An oblique incidence of the probe light is considered in the system to reduce the degradation of velocity difference between the electron and the laser light in samples. A time resolution of <100 fs is expected in the pulse radiolysis system for the analysis of utrafast physical and chemical reactions in nano-space.  
 
THPKF041 SSRF: A 3.5GeV Synchrotron Light Source for China target, cathode, laser, beamloading 2365
 
  • Z. Zhao, H. Xu
    SINR, Jiading, Shanghai
  The Shanghai Synchrotron Radiation Facility (SSRF) is an intermediate energy light source that will be built at Zhang-Jiang Hi-Tech Park in Shanghai. The SSRF consists of a 432 m circumference storage ring with an operating energy of 3.5GeV and a minimum emittace of 2.95 nm-rad, a full energy bosster, a 100MeV electron Linac and dozens of beamlines and experimental stations. The design of the SSRF accelerator complex evolves timely along the technological progress such as top-up injection, mini-gap undulator, superconducting RF system and etc. This paper reports the design progress and status of the SSRF project.  
 
THPKF043 Accelerators Use for Irradiation of Fresh Medicinal Herbs target, cathode, laser, beamloading 2368
 
  • R.D. Minea, M.M. Brasoveanu, M.R. Nemtanu, C. Oproiu
    INFLPR, Bucharest - Magurele
  • E. Mazilu, N. Radulescu
    Hofigal S.A., Bucharest - Magurele
  The paper presents the results regarding the electron beam irradiation of fresh Salvia Officinalis and Calendula Officinalis. Irradiation is already a well-known decontamination method, but it received less attention for medicinal plants, especially on fresh herbs. Microbial load behavior, antioxidant activity, and enzymatic inhibition activity were measured for doses between 1 and 50 kGy. Up to 5 kGy, herbs are decontaminated without any important alteration in the active principles, but they loose their fresh aspect easier than non-irradiated ones. The last effect could be useful for the extracting process in which herbs are stressed anyway.  
 
THPKF044 The Improvement of NSRRC Linac for Top-up Mode Operation target, cathode, laser, beamloading 2371
 
  • J.-Y. Hwang, J. Chen, J.-P. Chiou, K.-T. Hsu, S.Y. Hsu, K.H. Hu, T.C. King, C.H. Kuo, K.-K. Lin, C.-J. Wang, Y.-T. Yang
    NSRRC, Hsinchu
  • C.T. Pan
    NTHU, Hsinchu
  The performance of the 50 MeV linac at the National Synchrotron Radiation Research Center (NSRRC) was examined and has been improved recently. The major improved items were 1) adopting a command-charging scheme to replace the resonance charging for the linac modulator; and 2) gun electronics. As a result, the beam quality was improved in terms of its energy spectrum and stability. The correlation between the improvement of beam quality and component upgrading is analyzed. The influence of the beam quality improvement to the recently proposed top-up mode operation in 2005 will also be discussed in this report.  
 
THPKF045 Accelerator Physics Issues at NSRRC target, cathode, laser, beamloading 2374
 
  • C.-C. Kuo, H.-P. Chang, P.J. Chou, K.-T. Hsu, G.-H. Luo, H.-J. Tsai, M.-H. Wang
    NSRRC, Hsinchu
  Over the past decade, NSRRC has served the synchrotron light users with its 1.5 GeV third-generation storage ring. To provide stable hard x-ray for the x-ray community, two strong-field superconduting wigglers have been installed and three more will be put in such a low energy ring. A superconduting rf cavity is to replace the conventional ones and the beam current will be double too. Top-up injection study is underway. This paper presents the accelerator physics issues at NSRRC such as single particle dynamics and collective effects.  
 
THPLT078 Construction of FFAG Accelerators in KURRI for ADS Study laser, antiproton, gun, simulation 2673
 
  • M. Tanigaki, K. Mishima, S. Shiroya
    KURRI, Osaka
  • S. Fukumoto, Y. Ishi
    Mitsubishi Electric Corp, Energy & Public Infrastructure Systems Center, Kobe
  • M. Inoue
    SLLS, Shiga
  • S. Machida, Y. Mori
    KEK, Ibaraki
  KART (Kumatori Accelerator driven Reactor Test) project has started at Kyoto University Research Reactor Institute (KURRI) from the fiscal year of 2002. The purpose of this project is to demonstrate the basic feasibility of ADS, studying the effect of incident neutron energy on the effective multiplication factor of the subcritical nuclear fuel system. We are now constructing a proton FFAG accelerator complex as a neutron production driver for this project. Our accelerator complex consists of a 2.5 MeV FFAG betatron as an injector and 20 MeV and 150 MeV FFAG synchrotrons as a booster and a main ring, respectively. Our FFAG betatron is a spiral sector type. Both booster and main rings are radial sector type FFAG synchrotrons, but different in the production of required magnetic field with a certain magnetic field index. The distribution of magnetic field is determined by the shaped pole-face in the main ring while the magnetic field is realized by use of trim coils in the booster ring. This FFAG complex will be combined with our Kyoto University Critical Assembly (KUCA) in KURRI by the end of March 2006 and the experiments will begin as soon as the whole system is ready.  
 
THPLT079 The Study of APF-IH Linac laser, antiproton, gun, cathode 2676
 
  • K. Yamamoto, T. Hattori, K. Yamamoto
    RLNR, Tokyo
  • M. Okamura
    RIKEN, Saitama
  • S. Yamada
    NIRS, Chiba-shi
  We have manufactured the IH linac with Alternating Phase Focus as the test machine of medical accelerator injection. It will accelerate C4+ ion up to 2MeV/u from 40 keV/u, the tank length is around 1.5m, operation frequency is 100MHz. Furthermore, We have succeeded the acceleration test using proton with simple acceleration system consist of P.I.G. ion source, bending magnets and focus lenses, less than 5m long. Otherwise, We have been making the program of beam dynamics with the results of the electro-magnetic simulation soft (Micro-Wave-Studio,OPERA-3D), it has the merit of easily to calculate the 3D- beam dynamics in the tank. We will report the some results of the test and the beam simulation and the comparisons.  
 
THPLT080 Simulation Study of the Beam Loading Effect in an RF Gun laser, antiproton, gun, cathode 2679
 
  • K. Shinto, H. Hama, F. Hinode, A. Miyamoto, T. Tanaka
    LNS, Sendai
  Because of simple structure and apparatus, a thermionic rf gun has been considered to be employed in a new pre-injector for the future synchrotron radiation facility at Tohoku University. A 3-D beam simulation code for the rf gun using a Finite Difference Time Domain (FDTD) method to solve Maxwell's equations has been developed. In the rf gun, especially in case of the high beam current, electromagnetic fields induced by the electron beam are considered to affect beam characteristics such as beam emittance and energy spread. In the FDTD method, because the Maxwell?s equations are able to be solved including the term of current density of the charge, the electromagnetic fields produced by both the external rf power and the electron beam can be anticipated. Using the simulation code, beam loading effects on the characteristics of the electron beam extracted from the rf gun is investigated.  
 
THPLT081 Present Status of Photo-cathode RF Gun System and its Applications at Waseda University antiproton, electron, laser, cyclotron 2682
 
  • R. Kuroda, Y. Hama, K. Hidume, H. Hirama, M. Kawaguchi, N. Kudo, T. Kuribayasi, S. Minamiguchi, R. Moriyama, T. Saito, K. Sakaue, D. Ueyama, M. Washio
    RISE, Tokyo
  • H. Hayano, J. Urakawa
    KEK, Ibaraki
  • S. Kashiwagi
    ISIR, Osaka
  • X.J. Wang
    BNL/NSLS, Upton, Long Island, New York
  High quality electron beam generation using photo-cathode rf gun system and its application have been developed at Waseda University. This system can generate about 4 MeV low emittance electron beam. This is applied for soft X-ray generation using laser Compton scattering and pulse radiolysis experiments based on the pump-probe technique. In case of the soft X-ray generation, Compton scattering experiments between about 4.2 MeV electron beam and Nd:YLF laser light (1047nm) is performed at 20 degrees interaction angle, so that about 300 eV soft X-ray is generated. In case of the pulse radiolysis experiments, the electron beam is used for the pump beam. The probe light is generated as white light by concentrating Nd:YLF laser light (1047nm) on the water cell. The measurement with about 30 ps (FWHM) time resolution of this system is demonstrated for the absorption of hydrated electrons. In this conference, we will present the experimental results, status of this system and future applications.  
 
THPLT082 Beam Diagnostics for a Photocathode Rf-gun System antiproton, emittance, electron, cyclotron 2685
 
  • K. Sakaue, N. Kudo, R. Kuroda, M. Washio
    RISE, Tokyo
  • H. Hayano, J. Urakawa
    KEK, Ibaraki
  • S. Kashiwagi
    ISIR, Osaka
  Beam diagnostic systems for high quality electron beam emitted from photo-cathode rf gun have been developed. Beam characteristics such as bunch length and emittance measurements were performed at Waseda University. The bunch length was measured using an rms bunch length monitor based on beam spectrum analysis. The monitor is very useful as the non-destructive and conventional tool even for the relatively low energy electron beam around 5MeV. The measurement results of the rms bunch lengths using this monitor are in good agreement with the simulation results of PARMELA. However, it is not applicable for the measurement of longitudinal profile of the electron bunch, so that we have started the manufacturing of a deflection cavity, so-called RF-Kicker, to measure the longitudinal profiles of the bunch. The emittance has been measured by using a slit scan technique. By using double slit scan technique, emittance of 9mmmrad has been obtained. Though the value is not satisfactory small, we believe that much smaller emittance can be obtained by optimizing a laser profile. The measurement results and progress of rf gun at Waseda University will be presented at the conference.  
 
THPLT083 Femto-second Bunch Length Measurement using the RF Deflector antiproton, emittance, cyclotron, focusing 2688
 
  • S. Kashiwagi, G. Isoyama, R. Kato, K.K. Kobayashi, Y. Matsui, A. Saeki, J. Yang
    ISIR, Osaka
  • H. Hayano, M. Kuriki
    KEK, Ibaraki
  • M. Kudo, M. Washio
    RISE, Tokyo
  The traveling wave type rf cavities operating in dipole mode (TM110-like) is being developed for a measurement of femto-second electron bunch. The femto-second electron bunch is used the pulse radiolysis experiments for the studies on radiation physics and chemistry with femto-second time resolution. The resonant frequency is tuned to the designing value 2856 MHz, which is accelerating frequency of a photo-injector linac at ISIR Osaka University. Further, we are planning to apply the design of the traveling wave rf deflector to a X-band crab cavities for the Global Linear Collider (GLC) project. In this conference, we will report the design of the traveling wave rf deflector and the result of cold test.  
 
THPLT084 Test Result of Slow Global Orbit Feedback using MATLAB at PLS feedback, antiproton, emittance, cyclotron 2691
 
  • H.-S. Kang, J. Choi, K.M. Ha, E.-H. Lee, T.-Y. Lee, W.W. Lee
    PAL, Pohang
  A slow global orbit feedback using MATLAB has been tested to control the slow orbit movement for the PLS. The feedback program uses MATLAB tools such as matrix algebra, mathematical functions, and graphic display, and uses the SVD (singular value decomposition) method. The PLS uses 70 corrector magnets with the maximum angle of 2-mrad for each plane among which 11 use the 16-bit DAC power supplies for the insertion device orbit control and others the 12-bit corrector power supplies with the minimum step of 1-micro-rad, and thus the orbit feedback is not acceptable to beamline users. For the best performance of the feedback, the major hardware components have been upgraded: the replacement of 12-bit BPMs with 16-bit was completed, and the upgrade of corrector power supplies from DAC 12-bit to 18-bit or higher will be completed soon. In this paper, the orbit feedback test result using the current corrector power supplies is presented and the upgrade plan of orbit feedback is described.  
 
THPLT085 Reengineering and Refactoring Large-scale Scientific Programs with the Unified Process: A Case Study with OSIRIS PIC Program feedback, antiproton, emittance, cyclotron 2694
 
  • J.B.  Kim, I.S. Ko
    POSTECH, Pohang, Kyungbuk
  • H. Suk
    KERI, Changwon
  As science and engineering problems get more complex, programs which help modelling complicated problems larger and more sophisticated. This trend makes us recognize the importance of well-established engineering disciplines not only in designing large-scale scientific programs for special purposes in appropriate development time but also in importing the programs from other research group and refactor it for conveniences and more advanced applications. OSIRIS is a large-scale PIC code which was developed at UCLA for modelling of laser-plasma interactions. OSIRIS was reengineered and documented in UML by our group and ported to Linux cluster machine of 8 nodes. We report our current status of developing the extended version of OSIRIS, which was named as OSIRIS-X, and how a large-scale scientific programs can be enhanced efficiently with the Unified Process. Some guidelines in designing and refactoring large-scale scientific codes are presented and discussed. A common architecture model of numerically intensive programs for large-scale computing is suggested , and it is discussed how we can use it for rapid development and prototyping of scientific programs. We also discuss future challenges and prospects in OSIRIS-X development.  
 
THPLT086 High Temporal Resolution, Single-shot Electron Bunch-length Measurements feedback, electron, antiproton, emittance 2697
 
  • G. Berden, B. Redlich, A.F.G. Van der Meer
    FOM Rijnhuizen, Nieuwegein
  • W.A. Gillespie, A. MacLeod
    UAD, Dundee
  • S.P. Jamison
    Strathclyde University, Glasgow
  A new technique, combining the electro-optic detection of the Coulomb field of an electron bunch and the single-shot cross-correlation of optical pulses, is used to provide single-shot measurements of the shape and length of sub-picosecond electron bunches. As in our previous technique [I. Wilke et al., Phys. Rev. Lett. 88, 124801 (2002)], the electric field of the electron beam is encoded electro-optically on an optical pulse. Our earlier measurements, which involved encoding the time profile of the electron bunch on the spectrum of the optical pulse, showed electric field profiles with a FWHM of the order of 1.7 ps. The new method offers a much better time resolution since it avoids the significant measurement artifacts that can arise in our previous (spectral encoding technique due to the coupling between the temporal envelope and spectral content of the optical pulse. The cross-correlation technique has been applied to the measurement of electron bunches in FELIX, showing single bunches of around 500fs FWHM. The resolution is limited primarily by the electro-optic crystal thickness and the relatively low energy of the electrons (50 MeV).  
 
THPLT089 MATLAB Based TPSA Toolbox for the Particle Mapping Through Three-dimensional Magnetic Fields feedback, electron, antiproton, emittance 2700
 
  • H.-P. Chang, H.-J. Tsai
    NSRRC, Hsinchu
  Based on the object-oriented programming of MATLAB, a truncated power series algebra (TPSA) toolbox has been developed. The TPSA toolbox as a differential algebra has been applied to realize the algorithm of particle mapping through three-dimensional magnetic field configurations. The capability of symbolic calculation by using this MATLAB-based TPSA toolbox can be used for the theoretical simulation and modeling in accelerator physics. Associated with the use of MATLAB in the control of machines, one can derive the real machine with a virtual machine model built in MATLAB. In this paper, the method of symplectic mapping of three-dimensional magnetic fields is introduced and the structure of TPSA toolbox is presented. Applications of TPSA toolbox in the symplectic mapping of three-dimensional magnetic fields are demonstrated as well.  
 
THPLT090 The Operating of Digital Beam Position Monitor in NSRRC feedback, electron, antiproton, emittance 2703
 
  • C.H. Kuo, J. Chen, K.-T. Hsu, K.H. Hu, D. Lee
    NSRRC, Hsinchu
  The digital beam position monitors are configured to operation system in the NSRRC now. This integration includes of multi-channel access, channel calibration, gain control, and parameter control to meet various operation condition, perform functionality and performance evaluation. The programmability nature of DBPM system is essential for multi-mode high precision beam position measurement. The system will support high performance beam position, turn-by-turn beam position, tune and other diagnostic measurements. Control system interface was implemented to support the operation of DBPM system. T various aspects will be discussed and presented in this report.  
 
THPLT140 Commissioning of BL 7.2, the New Diagnostic Beamline at the ALS plasma, gun, proton, polarization 2780
 
  • F. Sannibale, D. Baum, A. Biocca, N. Kelez, T. Nishimura, T. Scarvie, E. Williams
    LBNL, Berkeley, California
  • K. Holldack
    BESSY GmbH, Berlin
  BL 7.2 is a new beamline at the Advanced Light Source (ALS) dedicated to electron beam diagnostics. The system, which is basically a hard x-ray pinhole camera, was installed on the storage ring in August 2003 and the commissioning with the ALS electron beam followed immediately after. In this paper, the commissioning results are presented together with the description of the relevant measurements performed for the beamline characterization.  
 
THPLT155 Development and Testing of a Low Group-delay Woofer Channel for PEP-II plasma, gun, proton, polarization 2819
 
  • J.D. Fox, L. Beckman, D. Teytelman, D. Van Winkle, A. Young
    SLAC, Menlo Park, California
  The PEP-II HER and LER require active longitudinal feedback to control coupled-bunch instabilities. The PEP-II RF systems use direct and comb loop feedback to reduce the cavity fundamental impedance, though the remaining low-mode impedance is providing the fastest growing unstable modes in both rings. Since commissioning the longitudinal feedback systems have used a dedicated "woofer" channel to apply the low-frequency correction kick via the RF system. The performance of this original controller is limited by the maximum gain that can be supported due to the processing delay (group delay), as well as the difficulty in configuring a common correction controller that acts via two correction paths. A dedicated low-mode signal processing system has been developed to allow higher damping rates. It is a digital processing channel, operating at a 10 MHz sampling rate, and implementing flexible 5 to 10 tap FIR control filters. The design of the channel and initial control filters is presented, as are initial machine experiments quantifying the damping and noise floor of this low group delay woofer system.  
 
THPLT156 Simulations of IP Feedback and Stabilization in the NLC plasma, gun, proton, polarization 2822
 
  • L. Hendrickson, J.C. Frisch, T.M. Himel, T.O. Raubenheimer, A. Seryi, M. Woodley
    SLAC, Menlo Park, California
  • G.R. White
    Queen Mary University of London, London
  Keeping nanometer-sized beams in collision is an essential component in achieving design luminosity in a linear collider. The NLC stabilization strategy is conservative by including enough redundancy so that if some piece doesn't work to specification or the incoming beam motion is worse than expected, the beams will still be kept in collision. We show simulation results with both realistic and pessimistic assumptions about the response of the ground motion, inertial stabilization, interbunch and intertrain feedback systems. By providing backup systems, and by assuming that some systems may perform more poorly than expected, we can achieve a high level of confidence in our ability to successfully stabilize the beams.  
 
THPLT157 Beam-based Feedback for the NLC Linac plasma, gun, proton, polarization 2825
 
  • L. Hendrickson, N. Phinney, A. Seryi, P. Tenenbaum, M. Woodley
    SLAC, Menlo Park, California
  The NLC linac train-by-train feedback system is designed to stabilize the beam trajectory, but is also a valuable element in the strategy for emittance preservation. New simulations employ improved strategies [*], allowing beam steering to be performed significantly less often than without the feedback system. Additional simulations indicate that the linac feedback can contribute towards successful operation at noisier sites.

* Beam-based Feedback Simulations for the NLC Linac, L. Hendrickson et al., LINAC, Monterey, California (2000)

 
 
THPLT161 Compton X-ray Source plasma, feedback, proton, polarization 2834
 
  • A.E. Vlieks, G. Caryotakis, D.W. Martin
    SLAC, Menlo Park, California
  • C.A. DeStefano, W.J. Frederick, J.P. Heritage, N.C. Luhmann Jr.
    UCD, Davis, California
  In an effort to develop a monochromatic, tunable source of X-rays in the 20-85 KeV energy range, a 5.5 cell X-band RF gun has been designed and tested. Together with a 1.05 m high gradient accelerating structure (an NLC Collider component), this system generates and accelerates a beam of electrons to energies greater than 60 MeV. Monochromatic X-rays are generated, via the Compton Effect, through a head-on collision of this beam with a multi-terawatt laser beam.We are currently measuring and analyzing the performance of the complete system, including the energy, monochromaticity and emittance of the electron beam, the laser system performance and the X-ray flux from the beam-laser interaction. A tunable, monochromatic X-ray source has important medical applications.We will report on the latest results as well as describe the experimental setup, components and diagnostics.  
 
THPLT162 Diagnosis of Coupling and Beta Function Errors in the PEP-II B-Factory plasma, feedback, proton, polarization 2837
 
  • M.H. Donald, T.M. Himel, S. Zelazny
    SLAC, Menlo Park, California
  The SLAC Control program has an automatic phase measuring system whereby the beta functions of the two storage rings are measured. This facility has recently been extended to measure coupling between the horizontal and vertical motion and to fit the measured values to their modes of propagation. This facility aids the diagnosis and correction of coupling and focusing errors.  
 
THPLT163 High-temperature Kicker Electrodes for High-beam-current Operation of PEP-II plasma, proton, polarization, laser 2840
 
  • U. Wienands, R. Akre, D.E. Anderson, S. Debarger, K. Fant, D. Kharakh, R.E. Kirby, A. Krasnykh, A. Kulikov, J. Langton
    SLAC, Menlo Park, California
  The strip line electrodes of the kickers used in the transverse bunch-by-bunch feedback systems see significant power deposition by beam and HOM-induced currents. This leads to elevated temperatures of the aluminum electrodes and will ultimately become a limit for the beam current in the Low Energy Ring. Heat is transported to the environment primarily by radiation from the blackened surface of the electrodes. In order to extend the beam-current range of these kickers, new electrodes have been fabricated from molybdenum which are able to run at significantly higher temperature, thus greatly increasing the efficiency of the radiative cooling of the electrodes. Blackening of the electrodes is achieved by oxidation in air at 1000°F using a recipe first applied in aviation research for supersonic aircraft. Emissivity was measured on coupons and a whole electrode to be about 0.6. In addition, the match at the terminations of the electrodes is improved following field calculations and measurements on a model of the kicker.  
 
THPLT165 Synchrotron Light Interferometry at JEFFERSON Lab plasma, proton, polarization, laser 2843
 
  • A. Freyberger, P. Chevtsov, T. Day, R. Hicks
    Jefferson Lab, Newport News, Virginia
  • J-C. Denard
    SOLEIL, Gif-sur-Yvette
  The hyper-nuclear physics program at JLAB requires an upper limit on the RMS momentum spread of dp/p<3e-5. The momentum spread is determined by measuring the beam width at a dispersive location (D~4m) in the transport line to the experimental halls. Ignoring the epsilon-beta contribution to the intrinsic beam size, this momentum spread corresponds to an upper bound on the beam width of σ_beam<120um. Typical techniques to measure and monitor the beam size are either invasive or do not have the resolution to measure such small beam sizes. Using interferometry of the synchrotron light produced in the dispersive bend, the resolution of the optical system can be made very small. The non-invasive nature of this measurement allows continuous monitoring of the momentum spread. Two synchrotron light interferometers have been built and installed at JLAB, one each in the Hall-A and Hall-C transport lines. The devices operate over a beam current range from 1uA to 100uA and have a spatial resolution of 10um. The structure of the interferometers, the experience gained during its installation, beam measurements and momentum spread stability are presented. The dependence of the measured momentum spread on beam current will be presented.  
 
THPLT166 Development of Injection and Optics Control Applications for the SNS Accumulator Ring plasma, proton, polarization, laser 2846
 
  • S.M. Cousineau, C. Chu, J. Galambos, S. Henderson, T. Pelaia, M. Plum
    ORNL/SNS, Oak Ridge, Tennessee
  • A.L. Leahman
    WSSU, Winston-Salem, North Carolina
  A large suite of physics software applications is being developed to facilitate beam measurement and control in the SNS accumulator ring. Two such applications are an injection control and measurement application, and a ring optics control application. The injection application will handle measurement and control of the linac beam position and angle at the stripper foil, and will be used to measure the twiss parameters of the linac beam at the foil. The optics control application will provide knobs for machine working point, chromaticity, arc phase advance, and harmonic correction. Both applications are written within the standard in-house XAL framework. Presented here are first versions of the applications, along with plans for future development and testing.  
 
THPLT167 SNS Laser Profile Monitor Progress plasma, proton, laser, polarization 2849
 
  • W. Blokland, A.V. Aleksandrov, S. Assadi, C. Deibele, W. Grice, S. Henderson, T. Hunter, P. Ladd, G.R. Murdoch, J. Pogge, K. Potter, T.J. Shea, D. Stout
    ORNL/SNS, Oak Ridge, Tennessee
  • V. Alexandrov
    BINP SB RAS, Protvino, Moscow Region
  SNS will use a Nd:YAG laser to measure transverse profiles in the 186-1000 MeV super-conducting LINAC (SCL) and Ti:Sapphire modelock 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 collected to provide a direct measurement of the transverse or longitudinal beam profile. We have successfully measured the transverse profile with a prototype system on the MEBT beam. The final SCL system uses an optical transport line that is installed alongside the 300 meter super-conducting LINAC to deliver laser light at 8 locations. Possible vibrations in the optical transport system can lead to inaccuracies in the profile measurement. We will use an active feedback system on a mirror to correct any vibration up to 2 KHz. In this paper we describe our vibration studies and vibration cancellation system as well as the progress in the design, installation and testing of various subsystems for both the transverse and the longitudinal profiles.  
 
THPLT168 XAL - The SNS Application Programming Infrastructure plasma, proton, laser, polarization 2852
 
  • J. Galambos, C. Chu, S.M. Cousineau, T. Pelaia, A. Shishlo
    ORNL/SNS, Oak Ridge, Tennessee
  • C. Allen, C. McChesney
    LANL/LANSCE, Los Alamos, New Mexico
  • W.-D. Klotz
    ESRF, Grenoble
  • I. Kriznar, A. Zupanc
    Cosylab, Ljubljana
  A Java programming infrastructure for high level applications has been developed and is being used for the Spallation Neutron Source (SNS). The framework provides a hierarchal view of the accelerator and hides much of the underlying control system details. The hierarchy is database configured, facilitating sharing of applications across different beamlines, shielding the programmer from detailed knowledge of signal names, and allowing wholesale updating of applications. An important aspect of the framework is an online model, which can be run for design values, live machine values or user selected tuning values. Sample applications will be shown.  
 
THPLT170 Finding the Circular Magnet Aperture which Encloses an Arbitrary Number of Midplane-centered Beam Ellipses plasma, proton, laser, polarization 2855
 
  • J.S. Berg
    BNL, Upton, Long Island, New York
  In specifying the magnets for an accelerator, one must be able to determine the aperture required by the beam. In some machines, in particular FFAGs, there is a significant variation in the closed orbit and beta functions over the energy range of the machine. In addition, the closed orbit and beta functions may vary with the longitudinal position in the magnet. It is necessary to determine a magnet aperture which encloses the beam ellipses at all energies and all positions in the magnet. This paper describes a method of determining the smallest circular aperture enclosing an arbitrary number of midplane-centered ellipses.  
 
THPLT171 Stochastic Cooling Studies in RHIC, II plasma, proton, laser, polarization 2858
 
  • M. Blaskiewicz, J.M. Brennan, J. Wei
    BNL, Upton, Long Island, New York
  Intra-beam scattering is unavoidable for highly charged heavy ions and causes emittance growth during the store for collision physics. A longitudinal bunched beam stochastic cooling system will confine the bunch within the RF bucket increasing the useful luminosity. A single bunch, Palmer cooling system is under investigation. We present data and compare them with theory.  
 
THPLT172 Self-adaptive Feed Forward Scheme for the SNS Ring RF System plasma, proton, laser, polarization 2861
 
  • M. Blaskiewicz, K. Smith
    BNL, Upton, Long Island, New York
  During one millisecond of injection stacking, the RF beam current varies from 0 to 50 Amperes. The control loops of the RF system are operative throughout this process. Acceptable setpoints will be found during commissioning, but as vacuum tubes age and beam currents increase these setpoints will become less optimal. A scheme by which the system can optimize itself is presented.  
 
THPLT173 RHIC BPM Performance: Comparison of Run 2003 and 2004 plasma, proton, laser, polarization 2864
 
  • R. Calaga, R. Tomas
    BNL, Upton, Long Island, New York
  Identification of malfunctioning BPMs plays an important role in any orbit or turn-by-turn analysis. Singular value decomposition (SVD)and Fourier transform methods were recently employed to identify malfunctioning BPMs at RHIC. A detailed statistical comparison between the two methods for Run 2003 was in good agreement and proved to be a robust method to identify faulty BPMs. We evaluate detailed BPM performance for different versions of BPM low-level software in 2003 and 2004.  
 
THPLT177 Maps for Fast Electron Cloud Simulations at RHIC plasma, proton, laser, polarization 2867
 
  • U. Iriso, S. Peggs
    BNL, Upton, Long Island, New York
  Luminosity in several colliders, including RHIC, is limited by the electron cloud effect. A careful re-distribution of the bunch pattern around the azimuth of a ring can decrease the average electron density for a fixed total bunch current, allowing the luminosity to be increased. In the search for a bunch pattern that maximizes the luminosity, a fast computer simulation is a key requirement. We discuss the use of fast polynomial maps to simulate the bunch to bunch evolution of the electron density at RHIC. Such maps are empirically derived from existing conventional slow simulation codes.  
 
THPLT179 MADX-UAL Suite for Off-line Accelerator Design and Simulation plasma, proton, laser, polarization 2870
 
  • N. Malitsky, R.P. Fliller III, F.C. Pilat, V. Ptitsyn, S. Tepikian, J. Wei
    BNL, Upton, Long Island, New York
  • F. Schmidt
    CERN, Geneva
  • R.M. Talman
    Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
  We present here an accelerator modeling suite that integrates the capability of MADX and UAL packages, based on the Standard eXchange Format (SXF) interface. The resulting environment introduces a one-stop collection of accelerator applications ranging from the lattice design to complex beam dynamics studies. The extended capabilities of the MADX-UAL integrated approach have been tested and effectively used in two accelerator projects: RHIC, where direct comparison of operational and simulated data is possible, and the SNS Accumulator Ring, still in its design phase.  
 
THPLT181 A Tomographic Technique for Magnetized Beam Matching plasma, proton, laser, polarization 2873
 
  • C. Montag, I. Ben-Zvi, J. Kewisch
    BNL, Upton, Long Island, New York
  To maintain low electron beam temperatures in the proposed RHIC electron cooler, careful matching of the magnetized beam from the source to the cooler solenoid is mandatory. We propose a tomographic technique to diagnose matching conditions. First simulation results will be presented.  
 
THPLT183 Results from the Commissioning of the NSRL Beam Transfer Line at BNL plasma, laser, polarization, luminosity 2876
 
  • N. Tsoupas, S. Bellavia, R. Bonati, K.A. Brown, I.-H. Chiang, C. Gardner, D. Gassner, S. Jao, I. Marneris, A. McNerney, D. Phillips, P. Pile, R. Prigl, A. Rusek, L. Snydstrup
    BNL, Upton, Long Island, New York
  The NASA SPACE RADIATION LABORATORY (NSRL) has started operations at the Brookhaven National Laboratory in 2003. The NSRL facility will be used by NASA to study radiation effects. The NSRL facility utilizes proton and heavy-ion beams of energies from 50 to 3000 MeV/n which are accelerated by the AGS_Booster synchrotron accelerator. The beams were extracted[1] ,and transported to a sample which is located 100 m downstream. To date, protons, 12C, 56Fe, 48Ti ion beams of various magnetic rigidities have been transported to the sample location. The NSRL beam transport line has been designed to employ octupole magnetic elements[2] which transform the normal (Gaussian) beam distribution on the sample into a beam with rectangular cross section, and uniformly distributed over the sample. No beam-collimation is applied along any point of the NSRL beam transport line and the beam focusing on the sample is purely magnetic. The experimental and theoretical horizontal and vertical beam envelopes of the first order optics will be presented. The theoretical beam profiles and uniformities at the location of the sample, when the magnetic octupoles are excited (third order optics), will be compared with the experimentally measured ones.  
 
THPLT184 An Online Longitudinal Vertex and Bunch Spectrum Monitor for RHIC plasma, laser, polarization, luminosity 2879
 
  • J. Van Zeijts, R. Lee
    BNL, Upton, Long Island, New York
  The longitudinal bunch profile acquisition system at RHIC was recently upgraded to allow online measurements of the bunch spectrum, and collision vertex location and shape. The system allows monitoring the evolution of these properties along the ramp, at transition and rebucketing, and at store conditions. We describe some of the hardware and software changes, and show an application of the system in optimizing the cogging of the colliding beams.  
 
THPLT186 Bunch Pattern Control in Top-up Mode at the SLS plasma, laser, polarization, luminosity 2882
 
  • B. Kalantari, T. Korhonen, V. Schlott
    PSI, Villigen
  One of the crucial issues in the advanced third generation light sources is the bunch pattern control in the storage ring, where various filling patterns are of interests for different experiments. The most important step is to keep a uniform charge distribution over all (electron) bunches during the top-up operation. Such a bunch pattern control has been implemented at the Swiss Light Source (SLS). It provides a filling pattern with bunch-to-bunch fluctuation of a few percent. Since a dependency of the medium term orbit stability on the actual filling pattern was observed in the past, the stability could significantly be improved. Three major ingredients have made the implementation possible: precise timing system, flexible control system and sophisticated diagnostics. The method is being used in the user operation recently and proved to be reliable. This paper describes the hardware and software involved in the mentioned technique.  
 
FRXCH01 Development of High Power Targets plasma, laser, polarization, target 276
 
  • G.S. Bauer
    FZJ/ESS, Jülich
  High power targets are at the very heart of most applications of accelerators to science and technology. With many projects aiming to utilize beams in the multi-megawatt power range, solid targets, in particular stationary ones, become increasingly difficult. Liquid metal targets have become the concept of choice. Designs cover a variety of concepts ranging from free jets to allow extraction of low energy ? highly ionizing radiation (pions and muons) to fully enclosed systems if neutron generation is the main goal. Mercury is often the preferred target material due to its liquid state at room temperature and other favourable properties. Designs aiming at high temperature operation depending on small neutron absorption rely on PbBi as target material. Liquid lithium is proposed for a deuteron stripping target for the IFMIF project. Questions that need to be solved include solid-liquid metal reactions, radiation effects, general liquid metal technology, handling of spallation products as well as design of components and subsystems. In addition, short pulse operation leads to the generation of pressure waves inside the targets and the need to control their consequences.  
Video of talk
Transparencies
 
FRXBCH01 Novel Ideas and R&D for High Intensity Neutrino Beams plasma, laser, polarization, target 281
 
  • K.J. Peach
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  Recent developments in neutrino physics, primarily the conclusive demonstration of neutrino oscillations in both atmospheric neutrinos and solar neutrinos, provide the first conclusive evidence for physics beyond the Standard Model of particle physics. The phenomenology of neutrino oscillations, for three generations of neutrino, requires six parameters - two squared mass differences, 3 mixing angles and a complex phase that could, if not 0 or pi, contribute to the otherwise unexplained baryon asymmetry observed in the Universe. Exploring the neutrino sector will requires very intense beams of neutrinos, and needs novel solutions.  
Video of talk
Transparencies
 
FRXBCH02 Towards Higher Luminosities in B and Phi Factories plasma, laser, polarization, target 286
 
  • P. Raimondi
    INFN/LNF, Frascati (Roma)
  A brief review of the performances of the existing Factories will be presented. Such machines have been proved extremely successful, for both particle and accelerator physics. To further extend their physics reach, several plans are under way to upgrade the existing colliders, in order to increase their luminosity up to an order of magnitude. Will also be described several new schemes and ideas to realize full ?Second Generation Factories? aimed at luminosities two order of magnitude higher then what achieved so far.  
Video of talk
Transparencies
 
FRYACH01 HICAT - The German Hospital-Based Light Ion Cancer Therapy Project plasma, laser, polarization, target 290
 
  • H. Eickhoff, T. Haberer, B. Schlitt, U. Weinrich
    GSI, Darmstadt
  At the University Clinics at Heidelberg /Germany the realization of a cancer Therapy facility using light and medium ions (from protons up to oxygen) has started. This facility will be capable to treat about 1000 patients per year by means of the 'intensity controlled rasterscan technique', that has been already successfully applied to about 200 patients since 1998 at the GSI therapy pilot project. The presentation will give an overview of the facility layout and especially the accelerator- and beam transport systems, capable to provide 3 treatment places with light ions between 50 and 430 MeV/u. Two treatment places are located after horizontal beam lines and one after an isocentric gantry. A further horizontal beam line for research and development activities is foreseen. Besides the technical description and the status and schedule for the project realization organizational aspects of this project will be discussed with the project leadership at the University Clinics, the strong technical assistance of GSI and the role of industrial partners.  
Video of talk
Transparencies
 
FRYBCH01 Clean Energy and the Fast Track to Fusion Power laser, polarization, target, plasma 295
 
  • C. Llewellyn Smith
    UKAEA Culham, Culham, Abingdon, Oxon
  The theoretical attractions of fusion are clear: used as fuel in a fusion power plant, the lithium in one laptop battery together with 40 litres of water would produce 200,000 kW hours of electricity in an environmentally benign manner. The Joint European Torus (JET), which has produced 16MW, has shown that fusion can work in practice. ITER (the International Tokamak Experimental Reactor) is now essential to test integration of the components at the heart of a fusion reactor, and confirm that a burning plasma, in a fusion device scaled up in all dimensions by a factor of two from JET, to power plant size, has the expected behaviour. ITER should confirm that a fusion power plant can be built. The challenge will then be to build a power plant that would be sufficiently reliable and robust to be economically viable. This will require intensive research and development on the materials needed to construct the plasma vessel and surrounding blanket. These materials will have to be tested under reactor conditions at a dedicated facility called IFMIF (International Fusion Materials Facility). Construction of IFMIF in parallel with ITER would put fusion firmly on the 'fast track' (strongly advocated by the British Government) to the construction of a commercial fusion power plant, which could in principle be in operation within 30 years. I shall describe how a fusion power plant would work, the advantages and disadvantages of fusion, and the challenges that lie ahead.  
Video of talk
Transparencies