EPAC 2006 - List of Keywords

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

coupling

Paper	Title	Other Keywords	Page
MOPCH026	A Biperiodic X-band RF Cavity for SPARC	simulation, controls, SLAC, scattering	101
	L. Ficcadenti, M.E. Esposito, A. Mostacci, L. Palumbo Rome University La Sapienza, Roma D. Alesini, B. Spataro INFN/LNF, Frascati (Roma) A. Bacci INFN-Milano, Milano
	The Frascati photo-injector SPARC (Pulsed Self Amplified Coherent Radiation Source) will be equipped with an X-band RF cavity for linearizing emittance to enhance bunch compression and for reducing bunch longitudinal energy spread. A biperiodic cavity working on the pi/2-mode offers some advantages in comparison to a conventional (periodic) cavity despite the need of accurate machining. A copper prototype made of 17 separated cells has been built following numerical simulation. In this paper we report on preliminary measurements of its RF properties. The main characteristics of the cooling system for the final device are also addressed.

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

MOPCH107	Tuning Procedure of the 6 Meter IPHI RFQ	rfq, dipole, LEFT, quadrupole	291
	O. Piquet, M. Desmons, A. France CEA, Gif-sur-Yvette
	In the framework of the IPHI project (High Intensity Proton Injector), the RFQ cavity is divided into 6 sections of 1 meter each, and assembled in 3 segments separated by coupling plates. We will present the tuning procedure of the aluminium RFQ cold model to set the accelerating mode frequency, a flat voltage profile and to minimize the dipole components of the accelerating voltage. This tuning procedure can be divided in three steps. First, dipole mode frequencies are adjusted with rods for the 3 separated segments. Second, RFQ end cells and coupling cells are tuned by mechanical machining of tuning plates. Third, using a fully automated bead-pull for the measurement of the field distribution inside every RFQ quadrants, the RFQ is tuned with 96 plungers in a small number of iterations. Tuning this 6-meter long cold model is a comprehensive training in view of the future tuning of the copper RFQ with the variable voltage profile.

MOPCH117	Mechanical Design and RF Measurement on RFQ for Front-end Test Stand at RAL	rfq, factory, simulation, vacuum	318
	P. Savage, Y.A. Cheng Imperial College of Science and Technology, Department of Physics, London A.P. Letchford CCLRC/RAL/ISIS, Chilton, Didcot, Oxon J.K. Pozimski CCLRC/RAL, Chilton, Didcot, Oxon
	This paper will present the mechanical design and preliminary results of a RF measurement system for the cold model of a 324MHz 4-vane RFQ, which is part of the development of a proton driver front end test stand at the Rutherford Appleton Laboratory (RAL) in the UK. The design concepts will be discussed and some issues in manufacturing of the RFQ will be pointed out, and specific modifications will be explained. Furthermore, results of thermal simulations of the RFQ will be presented together with RF simulations of the resonant frequency, the Q-value and the longitudinal field distribution.

MOPCH159	Coupler Design Considerations for the ILC Crab Cavity	dipole, luminosity, higher-order-mode, damping	430
	P. Goudket, C.D. Beard CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire G. Burt Microwave Research Group, Lancaster University, Lancaster
	Transverse deflecting cavities, such as the ILC crab cavity, commonly operate in the TM110 dipole mode. This means that in addition to the higher order modes (HOMs), that need to be controlled for every cavity, the fundamental TM010 mode and the other polarisation of the dipole mode also need to be damped. As the resonant frequency of the fundamental mode is much lower than the cut-off frequency of the beampipe, this mode becomes trapped in the cavity and difficult to extract using conventional HOM couplers, hence a dedicated coupler is likely to be required. The ILC crab cavities will require excellent damping of all undesirable modes in order to maintain maximum luminosity at the IP.

MOPCH175	High Power Testing RF System Components for the Cornell ERL Injector	ERL, klystron, linac, factory	472
	S.A. Belomestnykh, R.P.K. Kaplan, M. Liepe, P. Quigley, J.J.R. Reilly, C.K. Sinclair, V. Veshcherevich Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
	There are two high power 1300 MHz RF systms under development for the Cornell University ERL Injector. The first system, based on a 16 kWCW IOT transmitter, will provide RF power to a buncher cavity. The second system employs five 120 kWCW klystrons to feed 2-cell superconducting cavities of the injector cryomodule. All components of these systems were ordered and some have already been delivered, including the IOT transmitter (manufactured by Thales-BM), 20 kWCW AFT circulator, 170 kWCW circulators (Ferrite Co.) and two prototype input couplers for superconducting cavities. A special LN2 cryostat has been designed and built for testing/processing the input couplers. The results of the first high-power tests are presented.

MOPCH181	1.3 GHz Electrically-controlled Fast Ferroelectric Tuner	TESLA, controls, feedback, klystron	487
	V.P. Yakovlev Omega-P, Inc., New Haven, Connecticut J.L. Hirshfield Yale University, Physics Department, New Haven, CT S. Kazakov KEK, Ibaraki
	A fast, electrically-controlled tuner is described with parameters suitable for operation with the 9-cell SC accelerator structure of ILC. The tuner is based on a magic tee and two phase shifters that contain ferroelectric rings. The dielectric constant of the ferroelectric ring is altered by applying a 4.2 kV DC pulse that provides an RF phase shift from 0 deg to 180 deg. This, in turn allows a change of the input signal amplitude from zero to its maximum value, or a change in phase from 0 deg to 360 deg during the RF pulse. It is shown that the possibility of changing the cavity coupling to the input line during the RF pulse allows significant RF power savings, up to 12.5 MW for the 800 GeV ILC option. In addition, fast electrically-tuned amplitude and phase control with a feed-back system should be useful to compensate for possible phase deviations of the input RF fields in each cavity of ILC to match the cavity with the feeding transmission line as the beam load varies.

MOPCH182	The JLAB Ampere-class Cryomodule Conceptual Design	damping, FEL, impedance, BBU	490
	R.A. Rimmer, G. Ciovati, E. Daly, T. Elliott, J. Henry, W.R. Hicks, P. Kneisel, S. Manning, R. Manus, J.P. Preble, K. Smith, M. Stirbet, L. Turlington, L. Vogel, H. Wang, K. Wilson, G. Wu Jefferson Lab, Newport News, Virginia
	For the next generation of compact high-power FELs a new cryomodule is required that is capable of accelerating up to Ampere levels of beam current. Challenges include strong HOM damping, high HOM power and high fundamental-mode power (in operating scenarios without full energy recovery). For efficient use of space a high real-estate gradient is desirable and for economic operation good fundamental-mode efficiency is important. The technology must also be robust and should be based on well-proven and reliable technologies. For Ampere-class levels of beam current both halo interception and beam break-up (BBU) are important considerations. These factors tend to drive the designs to lower frequencies where the apertures are larger and the transverse impedances are lower. To achieve these goals we propose to use a compact waveguide-damped multi-cell cavity packaged in an SNS-style cryomodule.

MOPLS026	Monitoring of Interaction-point Parameters using the 3-dimensional Luminosity Distribution Measured at PEP-II	luminosity, lattice, monitoring, SLAC	598
	B.F. Viaud Montreal University, Montreal, Quebec W. Kozanecki CEA, Gif-sur-Yvette C. O'Grady, J.M. Thompson, M. Weaver SLAC, Menlo Park, California
	The 3-D luminosity distribution at the IP of the SLAC B-Factory is monitored using e⁺ e^- -> e⁺ e-, mu+ mu- events reconstructed online in the BaBar detector. The transverse centroid and spatial orientation of the luminosity ellipsoid provide a reliable monitor of IP orbit drifts. The longitudinal centroid is sensitive to small variations in the average relative RF phase of the beams and provides a detailed measurement of the phase transient along the bunch train. Relative variations in horizontal luminous size are detectable at the micron level. The longitudinal luminosity distribution depends on the e± overlap bunch length and the vertical IP beta-function betay. In addition to continuous online monitoring of all the IP parameters above, we performed detailed studies of their variation along the bunch train to investigate a temporary luminosity degradation. We also used controlled variations in RF voltage and beam current to extract separate measurements of the e⁺ and e^- bunch lengths. The time-history of the betay measurements, collected over a year of routine high-luminosity operation, are compared with HER & LER phase-advance data periodically recorded in single-bunch mode.

MOPLS029	Preliminary Study of a Crab Crossing System for DAFNE	luminosity, betatron, damping, simulation	607
	A. Gallo, D. Alesini, F. Marcellini, P. Raimondi, M. Zobov INFN/LNF, Frascati (Roma)
	The implementation of a crab crossing scheme at the Frascati Phi-factory DAFNE is under consideration, together with several other ideas and upgrades to increase the collider luminosity. The crab crossing is beneficial to the luminosity because it is expected to optimize the geometrical superposition of the colliding bunches and to weaken the synchro-betatron beam-beam resonances. The basic specifications of such a system, the expected luminosity increase, a preliminary design of the crab cavities and the architecture of the dedicated RF system are presented.

MOPLS050	Combined Phase Space Characterization at the PEP-II IP using Single-beam and Luminous-region Measurements	emittance, luminosity, lattice, simulation	655
	A.J. Bevan Queen Mary University of London, London Y. Cai, A.S. Fisher, C. O'Grady, J.M. Thompson, M. Weaver SLAC, Menlo Park, California W. Kozanecki CEA, Gif-sur-Yvette B.F. Viaud Montreal University, Montreal, Quebec
	We present a novel method to characterize the e ± phase space at the IP of the SLAC B-factory, that combines single-beam measurements with a detailed mapping of luminous-region observables. Transverse spot sizes are determined in the two rings with synchrotron-light monitors & extrapolated to the IP using measured lattice functions. The 3-D luminosity distribution, as well as the spatial dependence of the transverse-boost distribution of the colliding beams, are measured using e⁺ e^- –> mu+ mu- events reconstructed in the BaBar tracking detectors; they provide information on the luminous spot size, the e^- angular divergence & the vertical emittance. The specific luminosity, which is proportional to the inverse product of the overlap IP beam sizes, is continuously monitored using Bhabha-scattering events. The combination of these measurements provide constraints on the horizontal & vertical spot sizes, angular divergences, emittances & beta functions of both beams at the IP during routine high-luminosity operation. Preliminary results of this combined-spot size analysis are confronted with measurements of IP beta-functions & overlap IP beam sizes at low beam current.

MOPLS053	Beta-beat Correction Using Strong Sextupole Bumps in PEP-II	sextupole, luminosity, closed-orbit, SLAC	664
	G. Yocky SLAC, Menlo Park, California
	A method for correcting lattice beta mismatches has been developed for the PEP-II collider using orbit offsets in strong sextupoles. The solution is first predicted in the MAD program by modeling closed orbit bumps in the plane of correction at the sextupoles strongest in that plane. The derived solution is then tested in the machine to confirm the prediction and finally dialed into the machine under high-current conditions.

MOPLS083	Higher Order Mode Study of Superconducting Cavity for ILC Baseline	KEK, polarization, pick-up, dipole	747
	K. Watanabe GUAS/AS, Ibaraki H. Hayano, E. Kako, S. Noguchi, T. Shishido KEK, Ibaraki
	The superconducting cavity of ILC baseline shape is being developed at KEK-STF (Superconducting RF Test Facility). The Higher Order Mode (HOM) of the cavity is one study item for the development. The purpose of the HOM study is further optimization of TTF HOM coupler and measurement of the HOM field distribution and the polarization of the main dipole modes. The result will be applied to HOM readings of beam induced signal for the purpose of cavity offset position and angle of axis measurement relative to the beam. We tried to improve of TESLA-type HOM coupler for more small size and relaxation of second stop-band. The cold-model coupler was made, and the RF characteristic was measured. After HOM couplers welded to the KEK Baseline nine-cell SC cavity, Qext of fundamental mode and each HOM, field pattern of each HOM and polarization of dipole modes were measured by the network analyzer. The results of the improved HOM coupler are presented.

MOPLS104	The Progress in Developing Superconducting Third Harmonic Cavity	DESY, simulation, XFEL, TTF	804
	N. Solyak, H. Edwards, M. Foley, I.G. Gonin, E.R. Harms, T.K. Khabiboulline, D.V. Mitchell, D.O. Olis, A.M. Rowe Fermilab, Batavia, Illinois
	XFEL and TTF facilities are planning to use section with a few third harmonic cavities (3.9GHz) upstream of the bunch compressor to improve beam performances [1-2]. Fermilab is developing superconducting third harmonic section for TTFII upgrade. This section will include four cavities equiped with couplers and blade tuners, installed in cryostat. Up to now, two cavities are complete and one of them is under test. The status of the cavity development and preliminary test results are presented in the paper.

MOPLS115	A Spin Rotator for the ILC	emittance, linac, polarization, dipole	831
	P.O. Schmid, N.J. Walker DESY, Hamburg
	A spin rotator featuring an optic axis with straight vision is presented. This rotator utilizes three bends, two solenoid pairs and two correction devices. These correctors, named reflectors, are mandatory for removing the cross plane coupling introduced by the solenoids. It is shown how the solenoids have to be set up to achieve longitudinal IP polarization taking into account non-zero crossing angles at the interaction region and a linac following the curvature of the earth. Furthermore, the stability requirements for mechanical and electrical imperfections are analyzed.

MOPLS117	Tuning Algorithms for the ILC Beam Delivery System	sextupole, luminosity, emittance, quadrupole	837
	J.K. Jones CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
	Emittance preservation is an important aspect in the design and running of the International Linear Collider (ILC) with a direct consequence on the luminosity of the machine. The Beam Delivery System represents a major problem in this respect as it produces emittance dilution effects that are difficult to correct and that have a direct effect on the emittance as seen at the interaction point, and thus upon the luminosity of the machine. Tuning algorithms for this section of the machine rely on the correction of aberrations through the use of linear and higher order knobs, using corrections magnets distributed throughout the system. Alternative systems are also discussed. The design and implementation of these tuning algorithms, and their effectiveness in a variety of cases, are investigated and estimates made for tolerances on a variety of error sources. Simulations results are also presented for models of the ATF-2 accelerator under development at KEK, with comparisons made to the ILC design.

MOPLS120	Mitigation of Emittance Dilution due to Transverse Mode Coupling in the L-band Linacs of the ILC	emittance, linac, simulation, lattice	843
	R.M. Jones, R.M. Jones UMAN, Manchester R.H. Miller SLAC, Menlo Park, California
	The main L-band linacs of the ILC accelerate 2820 bunches from a center of mass of 10 GeV to 500 GeV (and in the proposed later upgrade, to 1 TeV). The emittance of the vertical plane is approximately 400 times less than that of the horizontal plane. Provided the vertical and horizontal mode dipole frequencies are degenerate, then the motion in each plane is not coupled. However, in reality the degeneracy will more than likely be removed with the eigen modes lying in planes rotated from the x and y planes due to inevitable manufacturing errors introduced in fabricating 20,000 cavities. This gives rise to a transverse coupling in the horizontal-vertical motion and can readily lead to a dilution in the emittance in the vertical plane. We investigate means to ameliorate this emittance dilution by splitting the horizontal-vertical tune of the lattice.

MOPLS135	Correction of Vertical Dispersion and Betatron Coupling for the CLIC Damping Ring	quadrupole, emittance, sextupole, dipole	873
	M. Korostelev, F. Zimmermann CERN, Geneva
	The sensitivity of the CLIC damping ring to various kinds of alignment errors have been studied. Without any correction, fairly small vertical misalignments of the quadrupoles and, in particular, the sextupoles, introduce unacceptable distortions of the closed orbit as well as intolerable spurious vertical dispersion and coupling due to the strong focusing optics of the damping ring. A sophisticated beam-based correction scheme has been developed to bring the design target emittances and the dynamic aperture back to the ideal value. The correction using dipolar correctors and several skew quadrupole correctors allows a minimization of the closed-orbit distortion, the cross-talk between vertical and horizontal closed orbits, the residual vertical dispersion and the betatron coupling.

MOPLS140	Tuning Algorithms for the ILC Damping Rings	emittance, damping, quadrupole, dipole	888
	J.K. Jones CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
	Emittance preservation is an important aspect in the design and running of the International Linear Collider with a direct consequence on the luminosity of the machine. One major area of concern is in the damping rings, where the extracted emittances set the effective lower limits for the rest of the machine. Algorithms for tuning this system have been investigated, and simulations have been performed to understand the design and implementation issues. The different algorithms have been applied to the various damping ring designs, and the effectiveness of each algorithm has been assessed. A preliminary recommendation of tuning algorithm, and its effectiveness under various conditions, is given.

TUPCH013	Numerical Calculations of Position Sensitivity for Linear-cut Beam Position Monitors	simulation, pick-up, vacuum, CERN	1022
	P. Kowina, A.A. Galatis, W. Kaufmann, J. Schoelles GSI, Darmstadt
	In this contribution the results of simulations performed for different geometries of linear-cut Beam Position Monitors (BPMs) are compared for two design types: i)based on metal electrodes and ii)using a metal coated ceramics. The advantage of the ceramic solution is a compact construction allowing easy positioning. Contrary, the construction based on the metal electrodes benefits from its simplicity. The main goals in optimization are the sensitivity and linearity of the position determination. High position sensitivity can be achieved by the reduction of the plate-to-plate cross talks caused by coupling capacities. For instance, the insertion of an additional guard ring into the gap between the active plates leads to an increase of the sensitivity by about 30%. This insertion is necessary in case of ceramic solution: The large ceramics permeability enlarges the coupling capacity by about a factor of four. The careful geometrical arrangement allows to avoid resonances in the interesting frequency range i.e. from 0.2 to 200MHz. The displayed simulations are performed using CST Microwave Studio. The investigated BPMs will be used in the FAIR facility presently under design at GSI.

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

TUPCH058	Very Small Beam Size Measurement by Reflective SR Interferometer at KEK-ATF	emittance, optics, damping, KEK	1142
	T. Naito, T. Mitsuhashi KEK, Ibaraki
	An SR interferometer with the Herschelian reflective optics has been developed for the measurement of several um beam size. The chromatic aberration of the optical system applied in the SR interferometer limits the resolution of SR interferometer. We used objective lens of the SR interferometer by a focusing mirror. For the convenience of observation of the interferogram, we applied Herschelian arrangement of the optics. The measured vertical beam size was less than 5um and the estimated vertical emittance was 1x10-11m at the KEK-ATF damping ring.

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

TUPCH082	The EuroTeV Confocal Resonator Monitor Task	CTF3, pick-up, vacuum, resonance	1202
	V.G. Ziemann, T. J. C. Ekelof, A. Ferrari, M. A. Johnson, E. A. Ojefors, A. B. Rydberg UU/ISV, Uppsala F. Caspers CERN, Geneva
	We describe the progress in the analysis of the confocal resonator monitor task which is part of the diagnostics workpackage of EuroTeV. The initial design was analyzed both numerically and experimentally and found limitations. We therefore digressed from strict confocality and report the numerical analysis and S-parameter measurements of a modified design. Furthermore, we discuss the mechanical design needed for planned tests with beam in CTF3 which requires integration of the monitor into the beam pipe, damping of trapped modes, and frequency tunability.

TUPCH100	Fiberoptics-based Instrumentation for Storage Ring Longitudinal Diagnostics	synchrotron, radiation, synchrotron-radiation, diagnostics	1247
	S. De Santis, J.M. Byrd, A. Ratti, M.S. Zolotorev LBNL, Berkeley, California Y. Yin Y.Y. Labs, Inc., Fremont, California
	Many beam diagnostic devices in today's synchrotron rings make use of the radiation emitted by the circulating particles. Such instruments are placed in close proximity of the accelerator, where in many instances they cannot be easily accessed for safety consideration, or at the end of a beamline, which because of its cost, can only move the light port a few meters away from the ring. We present a study on the coupling of synchrotron light into an optical fiber for all those application where the longitudinal properties of the beam are measured (i.e., bunch length, phase, intensity, etc.). By choosing an appropriate fiber it is possible to keep attenuation and dispersion at negligible values over a large bandwidth, so that this method would allow to have the diagnostic instruments directly in the control room, or wherever convenient, up to several hundred of meters away from the tunnel. This would make maintaining and replacing instruments, or switching between them, possible without any access to restricted areas. Additionally, the few components required to be near the ring (lenses and couplers) in order to couple the light into the fiber are intrinsically radiation-hard.

TUPCH106	Commissioning the SPEAR3 Diagnostic Beamlines	single-bunch, diagnostics, optics, photon	1259
	W.J. Corbett, C. Limborg-Deprey, W.Y. Mok, A. Ringwall SLAC, Menlo Park, California
	SPEAR 3 has two diagnostic beam lines: an x-ray pinhole camera and a visible/UV laboratory. The pinhole camera images ~8 keV dipole radiation on a phosphor screen with a remote computer to capture digital profile images. The visible/UV beam line features an 8 mm high GlidCop 'cold finger' to remove the x-ray core of the beam. The remaining light is deflected horizontally onto an optical bench where it is focused via reflective (Cassegrain) or refractive optics. The visible beam is then split into branch lines for a variety of experimental applications. This paper describes the experimental arrangement, data processing algorithms and measurements obtained with both systems.

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

TUPCH116	Waveguide Distribution Systems for the European XFEL	XFEL, DESY, klystron, linac	1286
	V.V. Katalev, S. Choroba DESY, Hamburg
	In the European X-ray FEL 32 superconducting cavities are connected to a 10 MW multibeam klystron through a waveguide distribution system. The basic waveguide system is a linear system. The XFEL tunnel has limited space for the waveguide system and therefore some new compact high power waveguide components like a motor driven phaseshifter, an iris tuner and an asymmetric shunt tee have been developed. Also alternative layouts of the waveguide distribution system which may have certain advantages have been designed. In this report we will present the different layouts and report on the status of the development of the different new waveguide components.

TUPCH118	Manufacturing and Testing of 2.45 GHz and 4.90 GHz Biperiodic Accelerating Structures for MAMI C	MAMI, vacuum, resonance, SLAC	1292
	A. Jankowiak, O. Chubarov, H. Euteneuer IKP, Mainz K. Dunkel, C. Piel, H. Vogel, P. vom Stein ACCEL, Bergisch Gladbach
	At the Institut fur Kernphysik (IKPH) of Mainz University the fourth stage of the Mainz Microtron (MAMI), a 855MeV to 1500MeV Harmonic Double Sided Microtron, is now on the verge of first operation. For this project ACCEL Instruments GmbH manufactured biperiodic, on axis coupled, standing wave accelerating structures at the frequencies of 2.45GHz and 4.90GHz. Four resp. eleven multicell sections were manufactured, low power characterized and after delivery tested at the high power test stand of IKPH. This paper describes the production and characterization of these structures, presents results of the high power tests, and compares these data with results gained at IKPH for an in house built 4.90GHz prototype and the 2.45GHz structures built in the 1980s. A. Jankowiak et al. "Design and Status of the 1.5 GeV-Harmonic Double Sided Microtron for MAMI", Proceedings EPAC2002, Paris, p. 1085.

TUPCH123	Dipole Stabilizing Rods System for a Four-vane RFQ: Modeling and Measurement on the TRASCO RFQ Aluminum Model at LNL	rfq, dipole, quadrupole, simulation	1301
	F. Grespan, A. Palmieri, A. Pisent INFN/LNL, Legnaro, Padova
	The Dipole Stabilizing Rods (DSR's) are devices used in order to reduce a priori the effect of perturbation on the operating mode of a four-vane RFQ caused by neighboring dipole modes by increasing the frequency spacing between the TE210 mode and dipole modes, without, in principle, affecting the quadrupole TE210 mode. They have proven to be particularly useful in the case of coupled RFQ's whose overall length is significantly greater than the operating wavelength. In this article we present a circuit model of such DSR's, that, used in combination with a transmission line model of a four vane RFQ, has allowed us to predict the dimensioning of the DSR's in the case of the aluminum model of TRASCO RFQ. The DSR parameters and, in general, the accuracy of the model have been also confirmed by HFSS simulations and by RF measurements on the above-mentioned model.

TUPCH127	Fine Grooving of Conductor Surfaces of RF Input Coupler to Suppress Multipactoring	electromagnetic-fields, simulation, KEKB, KEK	1310
	T. Abe, T. Kageyama, H. Sakai, Y. Takeuchi KEK, Ibaraki
	An RF input coupler to feed high power into an accelerating cavity with heavy beam loading undergoes many multipactoring zones due to the wide range of the input RF power. Furthermore, a regular coaxial line is more subject to multipactoring than a rectangular waveguide because of the uniformity of the electromagnetic field. Grooving the conductor surfaces of the coaxial line is a promising method to suppress multipactoring under any conditions expected in the above cases. This paper reports results of our multipactoring simulation study and the high power test of the input coupler with a grooved coaxial line.

TUPCH132	Higher Order Mode (HOM) Damper of 500 MHz Damped Cavity for ASP Storage Ring	insertion, synchrotron, storage-ring, damping	1325
	J. Watanabe, K. Nakayama, K. Sato, H. Suzuki Toshiba, Yokohama M. Izawa KEK, Ibaraki A. Jackson, G. LeBlanc, K. Zingre ASP, Clayton, Victoria T. Koseki RIKEN/RARF/CC, Saitama N. Nakamura, H. Sakai, H. Takaki ISSP/SRL, Chiba
	TOSHIBA has delivered the storage ring RF system for the Australian Synchrotron Project(ASP). Two pairs of the 500MHz Higher Order Mode(HOM) damped cavities were applied for this system. Two on-centered and one off-centered dampers were attached for damping the longitudinal HOM impedance down to less than 20kOhm/GHz. In order to reduce the coupling of off-center damper for accelerating mode and improve cooling power of damper, New HOM damper was designed by optimizing SiC absorber structure and damper antenna length using HFSS code. The design and manufacture of the new HOM damper and the test are described.

TUPCH133	Comparison of Measured and Calculated Coupling between a Waveguide and an RF Cavity Using CST Microwave Studio	simulation, linac, damping, higher-order-mode	1328
	J. Shi, H. Chen, S. Zheng TUB, Beijing D. Li LBNL, Berkeley, California R.A. Rimmer, H. Wang Jefferson Lab, Newport News, Virginia
	Accurate predications of RF coupling between an RF cavity and ports attached to it have been an important study subject for years for RF coupler and higher order modes (HOM) damping design. We report recent progress and a method on the RF coupling simulations between waveguide ports and RF cavities using CST Microwave Studio in time domain (Transit Solver). Comparisons of the measured and calculated couplings are presented. The simulated couplings and frequencies agree within ~ 10% and ~ 0.1% with the measurements, respectively. We have simulated couplings with external Qs ranging from ~ 100 to ~ 100, 000, and confirmed with measurements. The method should also work well for higher Qs, and can be easily applied in RF power coupler designs and HOM damping for normal-conducting and superconducting cavities.

TUPCH134	RF Characteristics of the PEFP DTL	controls, rfq, proton, klystron	1331
	H. S. Kim, Y.-S. Cho, H.-J. Kwon, K.T. Seol KAERI, Daejon
	A conventional 20 MeV Drift Tube Linac (DTL) for the Proton Engineering Frontier Project (PEFP) has been developed as a low energy section of a 100 MeV accelerator. The 20 MeV DTL consists of 4 tanks with 152 cells. The machine has a unique feature of driving the 4 tanks with a single klystron. Therefore it has several control knobs to compensate the errors of each tank during operation. To develop the RF control scheme, the variations of the RF parameters of each tank were measured under various environmental conditions such as wall temperature, cooling water temperature, and cooling water pressure. In addition, the behaviors of the RF parameters among the tanks were also monitored during high power operation. In this paper, the measurement results are discussed and the control scheme based on the results are proposed.

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

TUPCH137	Design of the RF System for 30 MeV Cyclotron	cyclotron, simulation, impedance, vacuum	1340
	I.S. Jung, D.H. An, J.-S. Chai, H.B. Hong, S.S. Hong, M.G. Hur, H.S. Jang, J. Kang, J.H. Kim, Y.-S. Kim, M.Y. Lee, T.K. Yang KIRAMS, Seoul K.H. Kwon SKKU, Seoul
	LAD (Lab. of Accelerator Development) in KIRAMS (Korea Institute of Radiological & Medical Sciences) developed 13MeV medical cyclotron, named by KIRAMS-13, for PET (Positron Emission Tomography) in 2001. Now, KIRAMS-13 is widespread in Korea through the national project, "Development of Cyclotron and FDG Synthesis module." But, there is just one cyclotron for SPECT(Single Photon Emission Computed Tomography) in Korea, which is made by IBA, Belgium. If some problems are happened, we should shut off the cyclotron until IBA engineer fixes them. So, we decide to develop a 30MeV cyclotron, named KIRAMS-30, which has high-performance compared with existing commercial cyclotrons and will install this machine to radioactive isotopes production and researches in Advanced Radiation Technology Institute. In this paper, we design RF system, such as cavity, power coupler, and so on. At design of RF components, we consider mechanical stability, RF heating and cooling, arcing and multipacting, low maintenance. We simulate KIRAMS-30 with MWS (MicroWave Studio) and present simulation results.

TUPCH142	Development of a Novel RF Waveguide Vacuum Valve	vacuum, CTF3, CLIC, electromagnetic-fields	1349
	A. Grudiev CERN, Geneva
	The development of a novel rf waveguide vacuum valve is presented. The rf design is based on the use of TE0n modes of circular waveguides. In the device, the T·10⁰¹ mode at the input is converted into a mixture of several TE0n modes which provide low-loss rf power transmission across the vacuum valve gap, these modes are then converted back into the T·10⁰¹ mode at the output. There are a number of advantages associated with the absence of surface fields in the region of the valve: 1)Possibility to use commercially available vacuum valves equipped with two specially designed mode converter sections. 2)No necessity for an rf contact between these two sections. 3)Increased potential for high power rf transmission. This technology can be used for all frequencies for which vacuum waveguides are used. The only drawback is that, in rectangular waveguides, mode converters from the operating mode into the T·10⁰¹ mode and back again are necessary. Experimental results for the 30 GHz valves developed for the CLIC Test Facility 3 (CTF3) are presented showing in particular that the rf power transmission losses are below 1%.

TUPCH148	201 MHz Cavity R&D for MUCOOL and MICE	vacuum, emittance, factory, collider	1367
	D. Li, S.P. Virostek, M.S. Zisman LBNL, Berkeley, California A. Bross, A. Moretti, B. Norris Fermilab, Batavia, Illinois J. Norem ANL, Argonne, Illinois H.L. Phillips, R.A. Rimmer, M. Stirbet Jefferson Lab, Newport News, Virginia M. Reep, D.J. Summers UMiss, University, Mississippi Y. Torun IIT, Chicago, Illinois
	We describe the design, fabrication and preliminary testing of the prototype 201 MHz copper cavity for a muon ionization cooling channel. Application of the cavity includes the Muon Ionization Cooling Experiment (MICE) as well as cooling channels for a neutrino factory or a muon collider. This cavity was developed by the US MUCOOL collaboration and is being tested in the MUCOOL Test Area (MTA) at Fermilab. In order to achieve a high accelerating gradient, the cavity beam irises are terminated by a pair of curved, thin beryllium windows. Several of the fabrication methods developed for this cavity and the windows are novel and offer significant cost savings compared to conventional construction methods. Cavity thermal and RF performance will be compared to FEA modeling predictions. RF commissioning results will be presented.

TUPCH158	High Power, Solid State RF Amplifiers Development for the EURISOL Proton Driver	controls, EURISOL, simulation, linac	1394
	F. Scarpa, A. Facco, D. Zenere INFN/LNL, Legnaro, Padova
	A 5 kW solid-state RF amplifier for the SPES and EURISOL projects has been built and extensively tested. High reliability and low cost are the main goals for this device, an evolution of a 2.5 kW unit previously developed and presented at EPAC 02. The description of the amplifier, especially designed for superconducting cavities, its characteristics and test results will be illustrated and discussed, as well as the design and construction of two new 10 kW amplifier units that have recently started.

TUPCH165	Compact Single-channel Ka-band SLED-II Pulse Compressor	scattering, LEFT, CLIC, linac	1411
	S.V. Kuzikov, S.V. Kuzikov, M.E. Plotkin, A.A. Vikharev Omega-P, Inc., New Haven, Connecticut J.L. Hirshfield Yale University, Physics Department, New Haven, CT
	Basic studies of factors that limit RF fields in warm accelerator structures require experiments at RF power levels that can only be produced from an intense drive beam, as with CLIC studies, or using pulse compression of output pulses from the RF source. This latter approach is being implemented to compress output pulses from the Yale/Omega-P 34-GHz magnicon to produce ~100-200 MW, 100 ns pulses. A new approach for passive pulse compression is described that uses a SLED-II-type circuit operating with axisymmetrical modes of the TE0n type that requires only a single channel instead of the usual double channel scheme. This allows avoidance of a 3-dB coupler and need for simultaneous fine tuning of two channels. Calculations show that with this device at 34 GHz one can anticipate a power gain of 3.3:1, and an efficiency of 66% for a 100 ns wide output pulse, taking into account losses and a realistic 50-ns long 180 degrees phase flip.

TUPLS008	A new HOM Water Cooled Absorber for the PEP-II B-factory Low Energy Ring	dipole, quadrupole, scattering, impedance	1499
	M. Kosovsky, N. Kurita, A. Novokhatski, J. Seeman, S.P. Weathersby SLAC, Menlo Park, California
	At high currents and small bunch lengths beam line components in the PEP-II B-factory experience RF induced heating from higher order RF modes (HOMs) produced by scattered intense beam fields. A design for a passive HOM water cooled absorber for the PEP-II low energy ring is presented. This device is to be situated near HOM producing beamline components such as collimators and provide HOM damping for dipole and quadrupole modes while minimizing impedance to the beam. We present a method of optimizing the impedance characteristics of such devices through the evaluation of loss factors and absorber effectiveness for specific modes using scattering parameter and wakefield analysis.

TUPLS042	First Cryogenic Tests of the Superconducting CH-structure	cryogenics, GSI, pick-up, resonance	1588
	H. Podlech, C. Commenda, H. Klein, H. Liebermann, U. Ratzinger, A.C. Sauer IAP, Frankfurt-am-Main
	The CH-structure is a new multi-cell drift tube structure operated in the TE21-mode and is well suited for the acceleration of low and medium beta ion and proton beams. Due to the mechanical stiffness room temperature as well as superconducting CH-cavities can be realised. A 19-cell, beta=0.1 superconducting CH-prototype cavity has been developed and built. First cryogenic tests have been performed at 4.5 K in Frankfurt successfully. An effective accelerating voltage of 3.6 MV has been achieved so far. This corresponds to an electric peak field of 23 MV/m. Actual measurements aim on a localisation of possible field emission centers, afterwards further surface preparation will take place.

TUPLS047	An Analysis of Lumped Circuit Equation for Side Coupled Linac (SCL)	SCL, linac, insertion, booster	1600
	V.G. Vaccaro, A. D'Elia Naples University Federico II and INFN, Napoli M.R. Masullo INFN-Napoli, Napoli
	The behaviour of a SCL module is generally described by resorting to an equation system borrowed from lumped circuit theories. This description holds for a narrow frequency band (mono-modal cavity behaviour). A milestone in this field is represented by the classical analysis made by Knapp & alii where the equations allow for the resonant frequencies of the cavities and the first and second order coupling constants. Eigenvalues and eigenvectors (resonant frequencies of the system and relevant current amplitudes) are also given. We show that the system is not correct in the second and last but one equations for the case of half cell termination and non zero second order coupling constants. Due to the relevance of this formulation and of the case treated, we pay a particular attention to find the missing terms in the above mentioned equation. We suggest a correction term, having in addition a deep meaning from electromagnetic point of view. By means of this term we may justify the analytical solution given by the authors. Some numerical examples are also given showing that a discrepancy appears comparing the new equations with the results of the non-correct formulation.

TUPLS049	A Rationale to Design Side Coupled Linac (SCL): a Faster and More Reliable Tool	SCL, linac, booster, simulation	1606
	V.G. Vaccaro, A. D'Elia Naples University Federico II and INFN, Napoli M.R. Masullo INFN-Napoli, Napoli
	A module of an SCL is formed by a cascade of two or more tanks, connected by a Bridge Couplers (BC) with an RF feeder, which realizes a well defined accelerating field configuration in all the coupled cavities. Even resorting to geometrical scaling for the design of the adjacent tanks in the module it is not possible to reproduce the same e-m parameters. In addition to this the BC's for each tanks have a different geometrical design because of phasing constraints. The standard procedure may leads a very slow convergence of the design to the optimum and it is not in general clear if the optimum is reached. In this paper a rationale for designing a module of an SCL will be described and it will be presented its application to PALME first module (30-3???MeV). From a lumped circuit model one may get useful relations between e-m global response of the system and single cell parameters. Therefore it provides a certain number of tools which are used for the designing steps in connection with the standard electromagnetic CAD's, the results of which were used as "measurements".

WEPCH004	Estimation of Transverse Coupling From Pinhole Images	emittance, resonance, radiation, wiggler	1921
	X.R. Resende, P.F. Tavares LNLS, Campinas
	The Brazilian Synchrotron Light Laboratory (LNLS) has recently started filling its storage ring straight sections with insertion devices. Last year a 2-Tesla Wiggler was successfully installed and integrated in the control system. An elliptically polarizing undulator is now under construction and scheduled to be installed in the next shutdown, by the end of the current year. The VUV beamline for the undulator is very demanding with respect to orbit stability and other beam parameters. Considerable reduction of the vertical emittance via reduction of the transverse coupling is a must in order for the undulator beamline to achieve its promised outstanding performance. In this paper we report on recent efforts to better understand the residual coupling in the machine and we describe preliminary proposals of viable solutions that aim at controlling the linear coupling within beamline specifications.

WEPCH024	Matrix Formulation for Hamilton Perturbation Theory of Linearly Coupled Betatron Motion	resonance, betatron, lattice, storage-ring	1975
	M. Takao JASRI/SPring-8, Hyogo-ken
	Linear coupled motion in a circular accelerator was successfully parametrized through the transfer matrix approach, where normal mode Twiss and coupling parameters are defined as an extension of Courand and Snyder formulation. However it is not straightforward to assign analytical expressions to the coupling parameters. On the other hand the coupled motion was analytically solved by the Hamilton perturbation theory, which ingeniously describes the resonance phenomena. In the perturbation theory, however, the symplectic structure of the coupled motion is obscure in turn. Hence, for the purpose of combining both the theories with each other with keeping the respective virtues, we develop the matrix formulation based on the Hamilton perturbation theory. Since we have already known the solution of equation of motion, we can construct the transfer matrix in terms of the solution. Thus we formulate the betatron motion with linear coupling resonance in analytic and symplectic manner. As an application of the formulation, we investigate the two-dimensional beam ellipse in an electron storage ring.

WEPCH030	Beam Dynamics of a 175MHz RFQ for an IFMIF Project	rfq, emittance, linac, quadrupole	1990
	S. Maebara, S. Moriyama, M.S. Sugimoto JAEA, Ibaraki-ken M.S. Saigusa Ibaraki University, Electrical and Electronic Eng., Ibaraki
	International Fusion Materials Irradiation Facility (IFMIF) is an accelerator-based neutron irradiation facility employing the D-Li stripping reaction, to produce the neutron field similar to the D-T Fusion reactor (2MW/m2, 20 dpa/year for Fe). The required beam current of 250 mA is realized by two beam lines of 125mA, and the output energies at injector, RFQ and DTL were designed to be 0.1, 5 and 40 MeV, respectively. The operation frequency of 175MHz was selected to accelerate the large current of 125mA. After an intensive beam simulation, the RFQ with a total length of 12.6　m was designed to keep the minimum emittance growth with the RF injection power of 2.3MW CW. For such a 12m-long RFQ, two coupling plates are indispensable in order to suppress higher modes in a longitudinal direction at least. From beam dynamics point views, the transmission co-efficient has been evaluated by TOUTATIS code, and it is found that the transmission decay within 0.5% can be achieved by employing a gap width of less than 4mm for a coupling plate design.

WEPCH043	On the Implementation of Experimental Solenoids in MAD-X and their Effect on Coupling in the LHC	LHC, optics, quadrupole, injection	2011
	A. Koschik, H. Burkhardt, T. Risselada, F. Schmidt CERN, Geneva
	The betatron coupling introduced by the experimental solenoids in the LHC is small at injection and negligible at collision energy. We present a study of these effects and look at possible corrections. Additionally we report about the implementation of solenoids in the MAD-X program. A thin solenoid version is also made available for tracking purposes.

WEPCH047	Procedures and Accuracy Estimates for Beta-beat Correction in the LHC	LHC, quadrupole, simulation, power-supply	2023
	R. Tomas, O.S. Brüning, S.D. Fartoukh, M. Giovannozzi, Y. Papaphilippou, F. Zimmermann CERN, Geneva R. Calaga, S. Peggs BNL, Upton, Long Island, New York F. Franchi GSI, Darmstadt
	The LHC aperture imposes a tight tolerance of 20% on the maximum acceptable beta-beat in the machine. An accurate knowledge of the transfer functions for the individually powered insertion quadrupoles and techniques to compensate beta-beat are key prerequisites for successful operation with high intensity beams. We perform realistic simulations to predict quadrupole errors in LHC and explore possible ways of correction to minimize beta-beat below the 20% level.

WEPCH050	Correction of Vertical Dispersion and Betatron Coupling for the TPS Storage Ring	emittance, quadrupole, sextupole, betatron	2032
	H.-J. Tsai, H.-P. Chang, P.J. Chou, C.-C. Kuo, G.-H. Luo, M.-H. Wang NSRRC, Hsinchu
	A proposed 3 GeV Taiwan Photon Source (TPS) is a low emittance (1.7 nm-rad) medium energy storage ring with 24 DBA cells. The vertical emittance due to betatron coupling and spurious vertical dispersion generated by the magnet errors and off-center orbits in sextupoles and quadrupoles are analyzed. The sensitivities due to magnetic alignment errors are estimated. Using the SVD method, the result of global vertical dispersion and betatron coupling correction is presented.

WEPCH055	A New Algorithm for the Correction of the Linear Coupling at TEVATRON	optics, kicker, controls, quadrupole	2047
	Y. Alexahin, E. Gianfelice-Wendt Fermilab, Batavia, Illinois
	The Fourier analysis of TBT data provides valuable information about the machine linear and non-linear optics. The recent upgrade of the Beam Position Monitors system made it possible to exploit this technique also at Tevatron. A program for the measurement and correction of the linear coupling based on this approach has been integrated in the TEVATRON control system. With respect to the method based on the empirical adjustment of the strength of the skew quadrupoles, the new method has the advantage of being faster and of allowing the measurement of the coupling also during the acceleration. Moreover it offers also information about the sum coupling coefficient and about the location of the sources of coupling.

WEPCH059	Linear Lattice Modeling of the Recycler Ring at Fermilab	quadrupole, lattice, storage-ring, controls	2056
	M. Xiao, V.P. Nagaslaev, A. Valishev Fermilab, Batavia, Illinois V. Sajaev ANL, Argonne, Illinois
	The Recycler Ring at Fermilab is a fixed 8 GeV kinetic energy storage ring, by the use of permanent magnets in the ring lattice. It is a strong focusing FODO lattice made up of either two gradient magnets or two quadrupoles(in dispersion free straight sections). The magnetic properties of all magnets used were measured before installation and surveyed in place to minimize possible errors. Nevertheless, substantial differences are found in tunes and beta functions between the existing linear model and the real storage ring. It results in difficulties when tuning the machine to new lattice conditions. We are trying to correct the errors by matching the model into the real machine using Orbit Response Matrix(ORM) method. The challenge with ORM particular in this ring and the results are presented in this paper.

WEPCH060	Linear and Nonlinear Coupling Using Decoupling Transformations	storage-ring, quadrupole, lattice, sextupole	2059
	A. Wolski, A. Sessler LBNL, Berkeley, California
	Linear coupling in a storage ring is conveniently analyzed in terms of transformations that put the single-turn map into block-diagonal form. Such a transformation allows us to define new variables, in which the dynamics are uncoupled. Thus, for example, the symplectic conditions are simply that the phase area in each of the uncoupled variables is preserved. In principle, a similar approach may be taken to nonlinear coupling; we discuss such an approach in this paper, giving some simple illustrations of the ideas, based on the well-known techniques of normal form analysis. We also discuss some obstacles to finding a nonlinear decoupling transformation in the general case.

WEPCH062	Precision Measurement and Improvement of Optics for e+, e^- Storage Rings	optics, lattice, quadrupole, betatron	2065
	Y.T. Yan, Y. Cai, W.S. Colocho, F.-J. Decker, J. Seeman, M.K. Sullivan, J.L. Turner, U. Wienands, M. Woodley, G. Yocky SLAC, Menlo Park, California
	Through horizontal and vertical excitations, we have been able to make a precision measurement of linear geometric optics parameters with a Model-Independent Analysis (MIA). We have also been able to build up a computer model that matches the real accelerator in linear geometric optics with an SVD-enhanced Least-square fitting process. Recently, with the addition of longitudinal excitation, we are able to build up a computer virtual machine that matches the real accelerators in linear optics including dispersion without additional fitting variables. With this optics-matched virtual machine, we are able to find solutions that make changes of many normal and skew quadrupoles for machine optics improvement. It has made major contributions to improve PEP-II optics and luminosity. Examples from application to PEP-II machines will be presented.

WEPCH064	Fast Compensation of Global Linear Coupling in RHIC using AC Dipoles	quadrupole, RHIC, resonance, injection	2071
	F. Franchi GSI, Darmstadt R. Calaga BNL, Upton, Long Island, New York R. Tomas CERN, Geneva
	Global linear coupling has been extensively studied in accelerators and several methods have been developed to compensate the coupling vector C using skew quadrupole families scans. However, scanning techniques can become very time consuming especially during the commissioning of an energy ramp. In this paper we illustrate a new technique to measure and compensate, in a single machine cycle, global linear coupling from turn-by-turn BPM data without the need of a skew quadrupole scan. The algorithm is applied to RHIC BPM data using AC dipoles and compared with traditional methods.

WEPCH075	Effect of Insertion Devices on Beam Dynamics of the Diamond Storage Ring Using Kick Maps	injection, lattice, resonance, storage-ring	2092
	B. Singh, A.I. Baldwin, R. Bartolini, I.P.S. Martin Diamond, Oxfordshire
	The effect of the all Phase-I Insertion Devices (IDs) on the beam dynamic of the Diamond storage ring has been investigated using the kick map modelisation of the IDs. Kick maps have been produced with high accuracy using the computer code RADIA, considering many longitudinal harmonics. The effect of IDs on the dynamic aperture, Touschek lifetime and injection efficiency in the low emittance lattice, was investigated considering both coupling errors and physical engineering apertures. Harmful resonances have been identified using Frequency Map Analysis (FMA) and full 6D tracking was performed to estimate the Touschek lifetime and the injection efficiency. Additionally, the kick maps have been used to generate feed-forward tables for compensation of linear optics distortion.

WEPCH087	Normal Form for Beam Physics in Matrix Representation	lattice, controls, CERN	2122
	S.N. Andrianov St. Petersburg State University, Applied Mathematics & Control Processes Faculty, St. Petersburg A.N. Chechenin FZJ, Jülich
	The modeling of long beam evolution dynamics in nonlinear accelerator structures has raised new interest in the effective methods of nonlinear effects calculation. Moreover, it is preferably to use both analytical tools and numerical methods for evolution modeling. Usually the standard numerical methods and computer codes are based on the concept of symplectic transfer maps, whereas the analytical tool is the theory of normal forms. The method of normal forms can be realized in symbolic and numerical modes easily enough. In this paper, we discuss the normal form theory based on the matrix formalism for Lie algebraic tools. This approach allows using well known methods of matrix algebra. This permits to compute necessary matrices step-by-step up to desired order of approximation. This procedure leads to more simple structure of matrix representation for very complicated structure of this map does not allow using this map for practical computing. Therefore, it is necessary to transform this map in more appropriate form. In another words the new matrix representation for the map is particularly simple and has explicit invariants and symmetries.

WEPCH095	Models to Study Multi-bunch Coupling through Head-on and Long-range Beam-beam Interactions	damping, LHC, simulation, CERN	2137
	T. Pieloni, W. Herr CERN, Geneva
	In the LHC almost 6000 bunches will collide in four interaction points where they experience head-on as well as clustered long range interactions. These lead to a coupling between all bunches and coherent beam-beam effects. For two colliding bunches this is well understood. However, for a large number of bunches colliding with different collision patterns, it results in a complex spectrum of oscillation frequencies with consequences for beam measurements and Landau damping. To study the coherent beam-beam modes, three complementary models have been developped and will be described in this report. Two of these methods rely on self-consistent multi-bunch and multi-particle tracking while the third is a semi-analytic model based on a complex matrix algorithm. The three methods together provide useful information about the beam-beam coupling of multi bunch beams and together provide a deeper insight into the underlying physics.

WEPCH096	Measurement and Correction of the 3rd Order Resonance in the Tevatron	sextupole, resonance, CERN, dipole	2140
	F. Schmidt CERN, Geneva Y. Alexahin, V.A. Lebedev, D. Still, A. Valishev Fermilab, Batavia, Illinois
	At Fermilab Tevatron BPM system has been recently upgraded resulting much better accuracy of beam position measurements and improvements of data acquisition for turn-by-turn measurements. That allows one to record the beam position at each turn for 8000 turns for all BPMs (118 in each plane) with accuracy of about 10^-20 μm. In the last decade a harmonic analysis tool has been developed at CERN that allows relating each FFT line derived from the BPM data with a particular non-linear resonance in the machine. In fact, one can even detect the longitudinal position of the sources of these resonances. Experiments have been performed at the Tevatron in which beams have been kicked to various amplitudes to analyze the 3rd order resonance. It was possible to address this rather large resonance to some purposely powered sextupoles. An alternative sextupole scheme allowed the suppression of this resonance by a good factor of 2. Lastly, the experimental data are compared with model calculations.

WEPCH100	Application of the Lie-transform Perturbation Theory for the Turn-by-turn Data Analysis	resonance, optics, lattice, betatron	2146
	Y. Alexahin Fermilab, Batavia, Illinois
	Harmonic analysis of turn-by-turn BPM data is a rich source of information on linear and nonlinear optics in circular machines. In the present report the normal form approach first introduced by R. Bartolini and F. Schmidt is extended on the basis of the Lie-transform perturbation theory to provide direct relation between the sources of perturbation and observable spectra of betatron oscillations. The goal is to localize strong perturbing elements, find the resonance driving terms - both absolute value and phase - that are necessary for calculation of the required adjustments in correction magnet circuits: e.g. skew-quadrupoles for linear coupling correction. The theory is nonlinear and permits to analyze higher order effects, such as coupling contribution to beta-beating and nonlinear sum resonances.

WEPCH113	Numerical Impedance Calculations for the GSI SIS-100/300 Kickers	kicker, impedance, injection, simulation	2179
	B. Doliwa, H. De Gersem, T. Weiland TEMF, Darmstadt
	Fast kicker modules represent a potential source for beam instabilities in the planned Facility for Antiproton and Ion Research (FAIR) at the Gesellschaft für Schwerionenforschung (GSI), Darmstadt. In particular, the more than fifty kicker modules to be installed in the SIS-100 and SIS-300 synchrotrons are expected to have a considerable parasitic influence on the high-current beam dynamics. Here we present our numerical investigations of the longitudinal and transverse kicker coupling impedances using a specialized electromagnetic field software. Besides the coupling to the external network, particular attention is paid to the question whether a resistively-coated ceramic beam pipe is able to reduce coupling impedances and ferrite heating significantly.

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

WEPCH153	Symplectic Interpolation	AGS, resonance, BNL, dipole	2284
	W.W. MacKay, A.U. Luccio BNL, Upton, Long Island, New York
	It is important to have symplectic maps for the various electromagnetic elements in an accelerator ring. For some tracking problems we must consider elements which evolve during a ramp. Rather than performing a complicated numerical integration for every turn, it should be possible to integrate the trajectory for a few sets of parameters, and then interpolate the transport map as a function of one or more parameters, such as energy. We present two methods for interpolation of symplectic matrices as a function of parameters: one method is based on the logarithm of the matrix, and the other is based on the related but simpler Healy symplectification method.

WEPCH164	High Power RF Tests of the First Module of the TOP Linac SCDTL Structure	linac, proton, booster, impedance	2313
	L. Picardi, C. Cianfarani, G. Messina, G.L. Orlandi, C. Ronsivalle ENEA C.R. Frascati, Frascati (Roma) E. Cisbani, S.F. Frullani ISS, Rome
	The TOP Linac (Oncological Therapy with Protons), under development by ENEA and ISS, is a sequence of three pulsed (5 microseconds, 300 Hz) linear accelerators: a 7 MeV, 425 MHz RFQ+DTL (AccSys Model PL-7), a 7-65 MeV, 2998 MHz Side Coupled Drift Tube Linac (SCDTL), and a 65-200 MeV, variable energy 2998 MHz Side Coupled Linac (SCL). The first SCDTL module structure, composed by nine DTL tanks coupled by eight side cavities, has been built. Low power RF measurements have shown good field uniformity and stability along the axis. The structure has been tested with a 1 - 4 MW power RF. Results of low and high power tests are reported and discussed.

WEPLS003	Simulation of MICE Using G4MICE	simulation, emittance, factory, quadrupole	2400
	C.T. Rogers Imperial College of Science and Technology, Department of Physics, London R. Sandstrom DPNC, Genève
	In the Muon Ionisation Cooling Experiment (MICE), muons will be fired one by one through one or two cooling cells. The experiment will be used to optimise simulation of an ionisation cooling channel for a future Neutrino Factory. This is achieved by measuring the position of each muon in six-dimensional phase space and examining the behaviour of muons collected into bunches offline. The experiment will be run with a number of different input beams, magnet configurations, RF configurations and absorber types. We present the simulated detector and cooling performance of the MICE cooling channel using the G4MICE simulation code for a range of configurations. We detail the simulation of engineering, field and detector models and examine the implications for the cooling efficacy and measurement.

WEPLS020	The RF Deflector for the CTF3 Delay Loop	klystron, CTF3, linac, vacuum	2436
	F. Marcellini, D. Alesini INFN/LNF, Frascati (Roma)
	In the CLIC Test Facility 3 (CTF3) a 42 m long ring, called delay loop, is used to halve the distance between bunches in the drive beam. The compression is obtained by merging two adjacent bunch trains from the linac deflected in opposite directions by an RF device, in such a way that the first train is forced to perform a full revolution in the delay loop, while the second one passes through. The length of the ring is an odd multiple of half the distance between bunches in the beam from the linac. The RF deflector consists of two identical cavities connected to the RF power source through a hybrid junction that equally splits the power and isolates the klystron from reflections. Its innovative design, the results of electromagnetic simulations and expected performances are described, together with low level RF measurements for test and characterization of the device before installation. Preliminary recombination results with the CTF3 beam are also shown. The RF deflector has also been used to measure the length of the accelerated bunches.

WEPLS042	Design and Experimental Investigation of an X-band Multilayer Dielectric Accelerating Structure	simulation, impedance, vacuum, DESY	2466
	A. Kanareykin, C.-J. Jing, P. Schoessow Euclid TechLabs, LLC, Solon, Ohio W. Gai, J.G. Power ANL, Argonne, Illinois
	A new project to significantly improve the efficiency of high gradient DLA structures is presented. A multilayer DLA where the single dielectric layer is replaced by a multiple coaxial layers of differing permittivity have been developed. The power attenuation in the multilayer structure is reduced by the Bragg Fiber principle where the dielectric layers are used to create multiple reflections in order to confine the accelerating mode fields for the most part in the dielectric, reducing the axial current on the conducting outer boundary. A design for an X-band multilayer structure operating in the TM03 mode using alternating dielectric layers with permittivities of 38 and 9.7 is discussed. In order to transfer the RF from the rectangular waveguide to the cylindrical one at TM03 mode, a special coupling and mode conversion scheme was developed. A prototype structure has been constructed and bench test results of the multilayer 11.424 GHz accelerator is presented.

WEPLS049	The Design of a Hybrid Photoinjector for High Brightness Beam Applications	gun, simulation, emittance, bunching	2487
	D. Alesini, M. Ferrario, V. Fusco, B. Spataro INFN/LNF, Frascati (Roma) L. Ficcadenti, A. Mostacci, L. Palumbo Rome University La Sapienza, Roma B. O'Shea, J.B. Rosenzweig, G. Travish UCLA, Los Angeles, California
	In this paper, we illustrate the electromagnetic and beam dynamics design procedure of a new class of photoinjector, a hybrid standing/traveling wave structure. In this device a standing wave RF gun section is integrated with a downstream traveling wave structure through a coupling cell that feeds simultaneously the two sections. We discuss the advantages in RF and beam performance of the hybrid photoinjector compared to conventional systems. The electromagnetic design has been performed using the 2D and 3D electromagnetic codes Superfish and HFSS. Results of beam dynamics simulations in different operating conditions are also discussed.

WEPLS107	Comparative Study of Inter-strand Coupling Current Models for Accelerator Magnets	dipole, LHC, CERN, GSI	2631
	R. de Maria, B. Auchmann, S. Russenschuck CERN, Geneva
	"Inter-Strand Coupling Currents" (ISCCs) contribute to field errors and losses in Rutherford-type superconducting cables in the time^- transient regime. The field change induces eddy currents in loops formed by the superconducting twisted strands and the resistive matrix. In the ROXIE program two models are implemented to simulate ISCCs in a magnet cross-section: A network model uses an electric circuit to represent the geometry of the twisted strands and their resistive contacts; an analytical model simplifies the network equations to determine an equivalent cable magnetization from an average field sweep over the cable. The implementation of the models in ROXIE allows to combine them with models for "Persistent Currents" and "Inter-Filament Coupling Currents". The non-linear iron yoke can be taken into account as well. The predictions of different ISCC models with regard to losses and field errors are compared for two design versions of the LHC main dipole. We find that as far as field quality is concerned, the models perform equally well. As for losses, however, the analytical model cannot capture the complexity of the problem and computes lower losses than the network model.

THOAFI03	Global and Local Coupling Compensation in RHIC using AC Dipoles	RHIC, quadrupole, dipole, sextupole	2774
	R. Calaga BNL, Upton, Long Island, New York F. Franchi GSI, Darmstadt R. Tomas CERN, Geneva
	Compensation of transverse coupling during the RHIC energy ramp has been proven to be non-trivial and tedious. The lack of accurate knowledge of the coupling sources has initiated several efforts to develop fast techique using turn-by-turn BPM data to identify and compensate these sources. This paper aims to summarize the beam experiments performed to measure the coupling matrix and resonance driving terms with the aid of RHIC ac dipoles.
	Transparencies

THOBFI02	Measurement of the Beam Profiles with the Improved Fresnel Zone Plate Monitor	damping, wiggler, optics, emittance	2784
	H. Sakai, N. Nakamura ISSP/SRL, Chiba H. Hayano, T. Muto KEK, Ibaraki
	We present the recent progress of the FZP (Fresnel Zone Plate) beam profile monitor constructed at KEK-ATF damping ring. This monitor based on an X-ray imaging optics with two FZPs. In this monitor, the transverse electron beam image at bending magnet is twenty-times magnified by the two FZPs and detected on an X-ray CCD camera. Then the real-time and 2-dimentional transverse beam profiles can be obtained with non-destructive manner by using this monitor. The expected spatial resolution is less than 1 micro-meter. Recently, we install the new mechanical shutter to improve time resolution of the monitor and avoid the effects of the short-term movement of the beam or the monitor itself. By applying this shutter, the shutter opening time was reduced less than 1ms and the beam profile could be measured more accurately. In this paper, we report the new shutter performance and the measurement results of beam profiles by the improved FZP beam profile monitor. K. Iida, et al. Nucl. Instrum. Meth. A 506 (2003) 41-49.
	Transparencies

THPCH006	Scaling Laws for the Montague Resonance	emittance, resonance, simulation, synchrotron	2796
	I. Hofmann, G. Franchetti GSI, Darmstadt
	The space-charge-driven Montague resonance is a source of emittance coupling in high-intensity accelerators with un-split tunes. Here we present scaling laws for the stop-band widths, growth rates and crossing behavior of this fourth order resonance. Our results on the coupling can be applied to circular machines as well as to linear accelerators. Based on self-consistent coasting beam simulation we show that for slow crossing of the stop-bands a strong directional dependence exists: in one direction the exchange is smooth and reversible, in the other direction it is discontinuous. We also discuss the combined effect of the Montague resonance and linear coupling by skew quadrupoles.

THPCH034	Transverse Coupling Impedances From Field Matching in a Smooth Resistive Cylindrical Pipe for Arbitrary Beam Energies	impedance, LHC, SIS, CERN	2853
	A.M. Al-Khateeb, A.M. Al-Khateeb, W.M. Daqa Yarmouk, Irbid O. Boine-Frankenheim, R.W. Hasse, I. Hofmann GSI, Darmstadt
	The transverse coupling impedance is investigated analytically. For an off-axis motion of the beam, the perturbed charge distribution of the beam becomes a function of the azimuthal angle, resulting to first order in the beam displacement in a dipole term which is the source of the transverse impedance. All six components of the electromagnetic field are different from zero and, therefore, both TM and TE modes will be excited in the beam-pipe and coupled to the beam at the inner surface of the resistive wall. Using the dipole source term, a linear combination of TM and TE modes is used to get closed form expressions for the transverse electromagnetic field components excited in the beam-pipe, and a generalized analytic expression for the corresponding transverse coupling impedance. It has been found that the contributions of the TM and the TE modes to the real part of the transverse resistive-wall impedance have similar dependence on the relativistic parameter but with opposite signs, the sum of both always being positive. Some approximate simple formulas for three important regions corresponding to small, intermediate and large frequencies in the ultrarelativistic limit were also obtained analytically.

THPCH045	Transverse Head-tail Modes Elimination with Negative Chromaticity and the Transverse Multi-bunch Feedback System at ELETTRA	feedback, ELETTRA, impedance, kicker	2886
	E. Karantzoulis, M. Lonza ELETTRA, Basovizza, Trieste
	The rigid dipole head-tail mode threshold at ELETTRA is by now quite low and increasing positively the chromaticity does not bring a much overall advantage in the machine performance. Using the bunch-by-bunch transverse feedback (TMFB), a threshold increase has been observed until the onset of the higher modes, which being bunch shape modes cannot be detected and therefore eliminated by the feedback system. To overcome this problem the machine has been set to a small but negative chromaticity. In this case the m=0 mode is unstable with a very low (<1 mA/bunch) threshold but the higher modes should be stable, especially when the main source of the transverse impedance comes from the resistive wall as in our case. Indeed when activating the TMFB no onset of any modes was observed within reasonable current limits (15 mA/bunch) that we plan to further investigate. In the paper after a theoretical discussion on the role of chromaticity and various types of impedances in the head-tail onset mechanism, the experimental results are presented and discussed.

THPCH058	Simulation Study on the Beneficial Effect of Linear Coupling for the Transverse Mode Coupling Instability in the CERN Super Proton Synchrotron	SPS, simulation, impedance, CERN	2916
	E. Métral, G. Rumolo CERN, Geneva
	The intensity threshold of the transverse mode coupling instability in a flat vertical chamber, as in the CERN Super Proton Synchrotron, is much higher in the horizontal plane than in the vertical one. This asymmetry between the transverse planes led us to the idea that linear coupling from skew quadrupoles could be used to increase the intensity threshold. This technique is already applied, for instance, in the CERN Proton Synchrotron, where a slow head-tail horizontal instability due to the resistive-wall impedance is stabilized by linear coupling only, i.e. with neither octupoles nor feedbacks. This paper presents the results of the study of the effect of linear coupling on the transverse mode coupling instability, using the HEADTAIL simulation code.

THPCH071	Coupling Impedances of Small Discontinuities for Non-ultrarelativistic Beams	impedance, dipole, vacuum, LANL	2949
	S.S. Kurennoy LANL, Los Alamos, New Mexico
	The beam coupling impedances of small discontinuities of an accelerator vacuum chamber have been calculated (e.g., * and references therein) for ultrarelativistic beams using Bethe's diffraction theory. Here we extend the results for an arbitrary beam velocity. The vacuum chamber is assumed to have an arbitrary, but fixed, cross section. The longitudinal and transverse coupling impedances are derived in terms of series over cross-section eigenfunctions, while the discontinuity shape enters via its polarizabilities. Simple explicit formulas for the circular and rectangular cross sections are presented. The impedance dependence on the beam velocity exhibits some unusual features. For example, the reactive impedance, which dominates in the ultrarelativistic limit, can vanish at a certain beam velocity, or its magnitude can exceed the ultrarelativistic value many times. *S. S. Kurennoy et al. Phys. Rev. ·10⁵² (1995) 4354.

THPCH083	A Tune Feedback System for the HERA Proton Storge Ring	quadrupole, acceleration, proton, feedback	2979
	S.G. Brinker, S.W. Herb, F.J. Willeke DESY, Hamburg Th. Lohse Humboldt University Berlin, Institut für Physik, Berlin
	The transverse tunes of an accelerator or storage ring are important parameters which have to be controlled and adjusted continuously during beam operation in order to assure good experimental background conditions. For the HERA proton storage ring, persistent current effects of the superconducting magnets are the main source for the inadequate repeatability of the tunes without a feedback while the proton beam is accelerated. A tune feedback has been developed, implemented and tested during beam acceleration and luminosity operation. Considering the different conditions during energy ramps and luminosity runs two versions of this feedback system have been established based on different correction and peak-finding algorithms (e.g. wavelet analysis). No additional excitation is needed on top of the standard tune indication system in HERA. The tunes could be kept constant during beam accceleration with a standard deviation of delta Q = 0.003. In luminosity runs where the tune control is more critical, first tests resulted in a standard deviation which was a factor of ten smaller. The feedback system is implemented as a standard tool for beam acceleration.

THPCH096	Intra Bunch Train Feedback System for the European X-FEL	pick-up, feedback, XFEL, controls	3017
	V. Schlott, M. Dehler, B. Keil, R. Kramert, A. Lounine, G. Marinkovic, P. Pollet, M. Roggli, T. Schilcher, P. Spuhler, D.M. Treyer PSI, Villigen
	After joining the preparatory phase of the European X-FEL project, the Paul Scherrer Institut (PSI) agreed in taking over responsibility for electron beam stabilization by developing a fast intra bunch train feedback (IBFB) system, which will be tested in its prototype version at the VUV-FEL facility at DESY. The IBFB will make use of the long bunch trains provided by the superconducting drive accelerators of the VUV- as well as the European X-FEL allowing to damp beam motions in a frequency range of a few kHz up to several hundreds of kHz applying modern control algorithms in a feedback loop. The FPGA-based, digital data processing and the low latency time (preferably < 200 ns) permit the elimination of long range (from bunch train to bunch train) and ultra fast (bunch by bunch) repetitive beam movements by adaptive feed forwards. In this paper, we will introduce the IBFB design concept and report on first test measurements with newly designed stripline beam position monitors for the VUV-FEL.

THPCH105	Summary of Coupling and Tune Feedback Results during RHIC Run 6, and Possible Implications for LHC Commissioning	feedback, RHIC, betatron, LHC	3044
	P. Cameron, A. Della Penna, L.T. Hoff, Y. Luo, A. Marusic, V. Ptitsyn, C. Schultheiss BNL, Upton, Long Island, New York M. Gasior, O.R. Jones CERN, Geneva C.-Y. Tan Fermilab, Batavia, Illinois
	Efforts to implement tune feedback during the acceleration ramp in RHIC have been hampered by the effect of large betatron coupling, as well as by the large dynamic range required by transition crossing with ion beams. Both problems have been addressed, the first by implementation of continuous measurement of coupling using the phase-locked tune meter, and the second by the development of the direct diode detection analog front end. Performance with these improvements will be evaluated during the first days of RHIC Run 6 beam commissioning. With positive results, the possibility of implementing operational feedback control of tune and coupling during beam commissioning will be considered. After beam commissioning, chromaticity feedback will be explored as a part of the accelerator physics experimental program. We will summarize the results of these investigations, and discuss possible implications of these results for LHC commissioning.

THPCH140	New Pulsed Current and Voltage Circuits Based on Transmission Lines	impedance, SLS, laser	3122
	V. Nassisi, F. Belloni, D. Doria, A. Lorusso, M.V. Siciliano, L. Velardi INFN-Lecce, Lecce
	We present two novel circuits able to compress current or voltage pulse named current compressor circuit (CCC) and voltage compressor circuit (VCC), and two novel amplifier circuits able to double the current or voltage pulse. The compressing circuits were composed by a transmission line, l long and a storage line, l/2 long. The CCC compressed the current pulse by a factor of 2 doubling its intensity, while the VCC compressed the voltage pulse by a factor of 2 doubling its amplitude. The amplifying circuits were composed by a R0 transmission line closed on a set of two parallel or series storage lines which doubled the intensity of the pulses. The current pulse amplifier (CPA) had two R0/2 storage lines in parallel, while the voltage pulse amplifier (VPA) had two 2R0 storage lines in series. The storage line was half long with respect to the input-pulse. In both circuits, one storage line was characterized by an open extremity and the other line by a closed extremity. Connecting the storage lines to suitable load resistors, R0/4, and 4R0 for the CPA and VPA, respectively, a twice of the pulse intensity was obtained. The circuits were studied by computer simulations.

THPCH149	Active RF Pulse Compression using Electrically Controlled Semiconductor Switches	simulation, SLAC, plasma, laser	3140
	J. Guo, S.G. Tantawi SLAC, Menlo Park, California
	In this paper, we present the recent results of our research on the ultra-high power fast silicon RF switch and its application on active X-Band RF pulse compression systems. This switch is composed of a group of PIN diodes on a high purity silicon wafer. The wafer is inserted into a cylindrical waveguide operating in the T·10⁰¹ mode. Switching is performed by injecting carriers into the bulk silicon through a high current pulse. Our current design uses a CMOS compatible process and the fabrication is accomplished at SNF (Stanford Nanofabrication Facility). The RF energy is stored in a room-temperature, high-Q 400 ns delay line; it is then extracted out of the line in a short time using the switch. The pulse compression system has achieved a gain of 11, which is the ratio between output and input power. Power handling capability of the switch is estimated at the level of 10MW.

THPCH160	Theoretical Study and Experimental Result of the RF Coupler Prototypes of Spiral 2	simulation, vacuum, SPIRAL2, pick-up	3170
	Y. Gómez-Martínez, D. Bondoux, JM. Carretta, J.-M. De Conto, M. Fruneau, A. Garrigue, D. Marchand, R. Micoud, E. Vernay, F. Vezzu LPSC, Grenoble P. Balleyguier CEA, Bruyères-le-Châtel M. Di Giacomo GANIL, Caen
	Spiral 2 is a 40 MeV superconducting linac under construction at GANIL. The RF couplers have to provide a 12 kW CW power to the cavities at 88 MHz. Two solutions corresponding to 2 different technologies have been designed and 2 prototypes have been built. We present the technical proposals and issues as well as the results (manufacturing, test at low and high power, multipacting…) leading to the final choice.

THPCH164	Progress and Status of the MICE Project	emittance, optics, quadrupole, alignment	3176
	A.P. Blondel DPNC, Genève P. Drumm CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
	The design of a Neutrino Factory (NF) has been the subject of several physics studies. For a NF based on a stored high energy muon beam, a potential key technology that has a significant impact on its cost and practicality is the ability to cool rapidly the muon beam prior to acceleration. The muon ionisation cooling experiment (MICE), currently being constructed at the Rutherford Appleton Laboratory (UK), is a demonstration of emittance cooling in a linear cooling channel. A new muon beam line and the basic infrastructure for MICE are funded, and a muon beam is under construction with an expected availability in spring 2007. The experiment will be methodically assembled over the following few years to bring the beam through RF accelerating cavities and liquid hydrogen absorbers and confined by a solenoidal magnetic field. The emittance of the beam before and after the cooling channel is measured in tracking spectrometers. The current status of the beam line and infrastructure build and of the components of MICE is presented.

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

THPCH195	New Developments on Low-loss Ferroelectrics for Accelerator Applications	controls, collider, linear-collider, plasma	3251
	A. Kanareykin, P. Schoessow Euclid TechLabs, LLC, Solon, Ohio A. Dedyk, S.F. Karmanenko Eltech University, St. Petersburg E. Nenasheva Ceramics Ltd., St. Petersburg V.P. Yakovlev Omega-P, Inc., New Haven, Connecticut
	Recent results on development of BST (barium strontium titanium oxide composition) ferroelectric materials are presented to be used as the basis for new advanced technology components suitable for high-gradient accelerators. Ferroelectric materials offer significant benefits for linear collider applications, in particular, for switching and control elements where a very short response time of 10 ns can be potentially achieved. The applications include: fast active X-band and Ka-band high-power ferroelectric switches, high-power X-band, and L-band ferroelectric-based phase-shifters. The recently developed large diameter (11 cm) BST-based ferroelectric rings will be used at high pulse power (tens of megawatts) for the X-band components as well as at high average power (in the range of a few kilowatts) for the L-band phase-shifters, which are suitable for ILC applications.

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

THPLS024	Controlling the Vertical Emittance Coupling in CAMD	wiggler, quadrupole, TESLA, resonance	3329
	V.P. Suller CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire M.G. Fedurin, P. Jines, D.J. Launey, T.A. Miller, Y. Wang LSU/CAMD, Baton Rouge, Louisiana
	The vertical beam size in the CAMD Light Source, as measured with an x-ray pinhole camera, indicates an emittance coupling ratio of 3%. This is consistent with the coupling ratio as measured by the betatron tune split when the coupling resonance is fully engaged. It has been shown that the coupling is mainly produced in the 7T wiggler, which is known to produce non-linear fields. To correct this coupling, it is proposed to install up to four skew quadrupoles. The results of testing a prototype skew quadrupole in the lattice are presented. It is shown that the coupling will be substantially corrected by suitably distributing and powering the four skew quadrupoles.

THPLS035	Next Generation Light Source Storage Ring at SPring-8	emittance, storage-ring, dynamic-aperture, sextupole	3362
	K. Tsumaki, N. Kumagai JASRI/SPring-8, Hyogo-ken
	A linac-based XFEL and an ERL are widely accepted as next-generation light sources. But they still have many technologically difficult problems to overcome. In contrast, electron beams in a storage ring are very stable. Thus, we examined the possibility of the storage ring as a next-generation light source. We designed a storage ring with an energy of 6 GeV and a circumference of 1436 m. The ring consists of 24 ten-bend achromat cells and has a natural emittance of 83 pm�rad. The circumference is equal to that of SPring-8 storage ring and the cell length is two times, which enables us to replace the existing storage ring with this new one in the SPring-8 tunnel and use the photon beam-lines without constructing new ones. Particle tracking simulation showed that the horizontal dynamic aperture at the center of a straight section is -3.7 mm and +3.4 mm and that it can be increased to -6.6 mm and +10.0 mm by changing the sextupole strength for chromaticity correction while keeping zero chromaticity. In this paper, we describe the design and the dynamic aperture of the extremely low emittance storage ring at SPring-8.

THPLS060	Lifetime and Acceptance at the SLS	scattering, SLS, emittance, resonance	3421
	A. Streun, Å. Andersson PSI, Villigen
	Beam lifetime at the storage ring of the Swiss Light Source (SLS) is limited by Touschek effect and elastic gas scattering. Both mechanism are affected by narrow gaps in the machine, elastic scattering directly by the vertical acceptance limitation, Touschek scattering via a possible restriction of lattice momentum acceptance due to coupling. The particle loss mechanism was explored by evaluations of lifetime as function of scraper position, chromaticity and emittance coupling.

THPLS061	Status of the Swiss Light Source	SLS, feedback, booster, injection	3424
	A. Lüdeke, Å. Andersson, M. Böge, B. Kalantari, B. Keil, M. Pedrozzi, T. Schilcher, V. Schlott, A. Streun PSI, Villigen
	The Swiss Light Source (SLS) is a 3rd generation synchrotron light source in operation since 2001. The paper will point out the recent activities to enhance machine operation and provides an overview about the new beamlines currently under construction at the SLS.

THPLS067	Vertical Beam Size Control in TLS and TPS	emittance, feedback, quadrupole, betatron	3442
	C.-C. Kuo, H.-P. Chang, J.-R. Chen, P.J. Chou, K.-T. Hsu, G.-H. Luo, H.-J. Tsai, D.-J. Wang, M.-H. Wang NSRRC, Hsinchu A. Chao SLAC, Menlo Park, California W.-T. Weng BNL, Upton, Long Island, New York
	Vertical beam size control is an important issue in the light source operations. The horizontal-vertical betatron coupling and vertical dispersion were measured and corrected to small values in the TLS 1.5 GeV storage ring. Estimated beam sizes are compared with the measured values. By employing an effective transverse damping system, the vertical beam blow-up due to transverse coherent instabilities such as the fast-ion beam instability was suppressed and as a result, the light source is very stable. In NSRRC we are designing an ultra low emittance 3-GeV storage ring and its designed vertical beam size could be as small as a few microns. The ground and mechanic vibration effects, and coherent instabilities could spoil the expected photon brightness due to blow-up of the vertical beam size if not well taken care of. The contributions of these effects to vertical beam size increase will be evaluated and the counter measures to minimize them will be proposed and reported in this paper.

THPLS068	Design of Taiwan Future Synchrotron Light Source	emittance, dynamic-aperture, lattice, synchrotron	3445
	C.-C. Kuo, H.-P. Chang, C.-T. Chen, P.J. Chou, H.J. Jhao, G.-H. Luo, H.-J. Tsai, M.-H. Wang NSRRC, Hsinchu
	We report updated design works for a new 3-3.3 GeV synchrotron light source with a high performance and low emittance storage ring, called Taiwan Photon Source (TPS). With its natural horizontal emittance less than 2 nm-rad and low emittance coupling, TPS will be able to provide an extremely bright photon beam to the demanding users, especially the x-ray community. The lattice type of the TPS is a 24-cell DBA structure and the circumference is 518.4 m. We present the lattice design, the accelerator physics issues and its performances.

THPLS138	Fast Polarization Switching at the SLS Microspectroscopy Beamline POLLUX	SLS, dipole, feedback, polarization	3610
	M. Böge, U. Flechsig, J. Raabe, T. Schilcher PSI, Villigen
	POLLUX is a new microspectroscopy facility which will be operated at a bending magnet at the Swiss Light Source (SLS). It offers spectroscopy with sub-micrometer spatial resolution for polymer science and magnetism. First user operation is scheduled for summer 2006. One of the novel envisaged options of the beamline is the usage of circular polarized light. The circular polarization will be generated by a localized angular steering of the electron beam within the bending magnet. This is accomplished by means of the global fast orbit feedback system of the SLS which allows to stabilize the electron beam to the sub-micrometer level up to frequencies of ~100 Hz. Due to the adapting coupling compensation involving dedicated adjacent skew quadrupoles, this steering becomes practically transparent to the other beamlines. Polarization switching rates of a few Hz are within reach.