EPAC 2004 - List of Keywords

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

linac

Paper	Title	Other Keywords	Page
MOYCH01	The TESLA XFEL Project	electron, photon, undulator, laser	11
	H. Weise DESY, Hamburg
	The overall layout of the X-Ray FEL to be built in international collaboration at DESY will be described. This includes the envisaged operation parameters for the linear accelerator which will use TESLA technology. Main emphasis is put on the specification of the superconducting accelerator modules. Other linac components will be described as well. Work packages needed to finalize the linac design will be presented. A summary of the status of the preparation work will be given.
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MOYCH02	Physics Challenges for ERL Light Sources	electron, emittance, brightness, synchrotron	16
	L. Merminga Jefferson Lab, Newport News, Virginia
	We present an overview of the physics challenges encountered in the design and operation of Energy Recovering Linac (ERL) based light sources. These challenges include the generation and preservation of low emittance, high-average current beams, manipulating and preserving the transverse and longitudinal phase space, control of the multipass beam breakup instability, efficient extraction of higher order mode power and RF control and stability of the superconducting cavities. These key R&D issues drive the design and technology choices for proposed ERL light sources. Simulations and calculations of these processes will be presented and compared with experimental data obtained at the Jefferson Lab FEL Upgrade, a 10 mA ERL light source presently in commissioning, and during a 1 GeV demonstration of energy recovery at CEBAF.
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MOZCH02	Start to End Simulations of Low Emittance Tuning and Stabilization	simulation, luminosity, collider, linear-collider	31
	P. Tenenbaum, A. Seryi, M. Woodley SLAC, Menlo Park, California D. Schulte CERN, Geneva N.J. Walker DESY, Hamburg G.R. White Queen Mary University of London, London
	The principal beam dynamics challenge to the subsystems between the damping ring and the collision point of future linear colliders is expected to be the tuning and stabilization required to preserve the transverse emittance and to collide nanometer-scale beams. Recent efforts have focused on realistically modelling the operation and tuning of this region, dubbed the Low Emittance Transport (LET). We report on the development of simulation codes which permit integrated simulation of this complex region, and on early results of these simulations. Future directions of LET simulation are also revealed.
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MOOCH02	First Full Beam Loading Operation with the CTF3 Linac	beam-loading, gun, acceleration, instrumentation	39
	R. Corsini, H.-H. Braun, G. Carron, O. Forstner, G. Geschonke, E. Jensen, L. Rinolfi, D. Schulte, F. Tecker, L. Thorndahl CERN, Geneva M. Bernard, G. Bienvenu, T. Garvey, R. Roux LAL, Orsay A. Ferrari Uppsala University, Uppsala L. Groening GSI, Darmstadt R.F. Koontz, R.H. Miller, R.D. Ruth, A.D. Yeremian SLAC, Menlo Park, California T. Lefevre NU, Evanston
	The aim of the CLIC Study is to investigate the feasibility of a high luminosity, multi-TeV linear e⁺e^- collider. CLIC is based on a two-beam method, in which a high current drive beam is decelerated to produce 30 GHz RF power needed for high-gradient acceleration of the main beam running parallel to it. To demonstrate the outstanding feasibility issues of the scheme a new CLIC Test Facility, CTF3, is being constructed at CERN by an international collaboration. In its final configuration CTF3 will consist of a 150 MeV drive beam linac followed by a 42 m long delay loop and an 84 m combiner ring. The installation will include a 30 GHz high power test stand, a representative CLIC module and a test decelerator. The first part of the linac was installed and commissioned with beam in 2003. The first issue addressed was the generation and acceleration of a high-current drive beam in the "full beam loading" condition where RF power is converted into beam power with an efficiency of more than 90%. The full beam loading operation was successfully demonstrated with the nominal beam current of 3.5 A. A variety of beam measurements have been performed, showing good agreement with expectations.
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MOOCH03	Status of a Linac RF Unit Demonstration for the NLC/GLC X-band Linear Collider	linear-collider, collider, klystron, feedback	42
	D.C. Schultz, C. Adolphsen, D.L. Burke, J. Chan, S. Doebert, V.A. Dolgashev, J.C. Frisch, R.K. Jobe, D.J. McCormick, C.D. Nantista, J. Nelson, M.C. Ross, T.J. Smith, S.G. Tantawi SLAC, Menlo Park, California D.P. Atkinson LLNL, Livermore, California Y.H. Chin, S. Kazakov, A. Lounine, T. Okugi, N. Toge KEK, Ibaraki
	Designs for a future TeV scale electron-positron X-band linear collider (NLC/GLC) require main linac units which produce and deliver 450 MW of rf power at 11.424 GHz to eight 60 cm accelerator structures. The design of this rf unit includes a SLED-II pulse compression system with a gain of approximately three at a compression ratio of four, followed by an overmoded transmission and distribution system. We have designed, constructed, and operated such a system as part of the 8-Pack project at SLAC. Four 50 MW X-band klystrons, running off a common 400 kV solid-state modulator, drive a dual-moded SLED-II pulse compression system. The compressed power is delivered to structures in the NLCTA beamline. Four 60 cm accelerator structures are currently installed and powered, with four additional structures and associated high power components available for installation late in 2004. We describe the layout of our system and the various high-power components which comprise it. We also present preliminary data on the processing and initial high-power operation of this system.
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MOPKF006	Enhancements of Top-up Operation at the Swiss Light Source	injection, storage-ring, controls, booster	309
	B. Kalantari, T. Korhonen, A. Lüdeke, C. Quitmann PSI, Villigen
	Since the first experience on 2001, Top-Up is the standard mode of operation at the Swiss Light Source (SLS) for users. In order to fulfill the ongoing demands of machine experts and experiments we have had to add more functionality to the Top-Up mode thus make it more flexible. Some time-resolved experiments require a constant charge in a single isolated bucket in the gap of the normal filling of a bunch train of 80% of the circumference of the storage ring. Therefore the Hybrid application was developed that keeps the beam current distribution constant in this mode. We developed a maintenance mode too, to allow to work continuously on the Linac and booster - for example to optimize injection/extraction - without disturbing the Top-up for user operation. Even beam destructive experiments at the Linac during Top-Up or Hybrid operation are supported, where the Linac can be used synchronously at the times between successive refilling of the storage ring. The flexible control and timing systems at the SLS made these applications feasible. We describe the controls, operation and applications of each of the above functionalities in this paper.

MOPKF009	Photoinjector Studies for the BESSY Soft X-ray FEL	gun, emittance, focusing, electron	315
	F. Marhauser BESSY GmbH, Berlin
	A linac driven soft X-Ray FEL facility has been proposed at BESSY with the aim to produce high brilliance photon beams within the energy range of 20eV to 1keV. The driver linac is based on superconducting (sc) L-Band rf-technolgy to enable cw operation of the FEL. As the electron beam emittance directly influence the photon beam characteristics, transverse slice emittances of 1.5pimmmrad are envisaged as a target goal. This demands for a high brilliance laser driven photoinjector rf-gun as electron source. For the first years of operation it is intended to use well known normal conducting (nc) L-Band rf-gun technology thereby restricting the macropulse repetition rate to 1 kHz to cope with the thermal power dissipation. At a later stage the nc rf-gun shall be replaced by a sc rf-gun, which is favoured conceptually as it allows to generate outmost flexible bunch patterns according to the needs of the experiments by fully exploiting the capabilities of the sc linac. This paper details the design considerations for a high power nc rf-gun complemented by results of beam dynamic studies up to the exit of the booster linac using ASTRA. Perspectives for the use of a sc photoinjector gun cavity are addressed.

MOPKF013	The Influence of the Main Coupler Field on the Transverse Emittance of a Superconducting RF Gun	gun, emittance, electron, pick-up	327
	D. Janssen FZR, Dresden M. Dohlus DESY, Hamburg
	For the Rossendorf superconducting RF gun project the influence of the additional RF field, created in the cavity by the RF power flow at the main coupler, is discussed. One end of the gun cavity is occupied by the cathode insert, so all flanges are concentrated on the other end. In the "flange plane" of the cavity two HOM coupler, the pic up and the main coupler are located. If we normalize the RF field in the cavity by the condition Eacc = 25MV/m and assume a beam power of 10kW (CW mode), we obtain an quality factor Qext = 2.210*7. A three dimensional field calculation using the MAFIA code, gives the field perturbation near the main coupler. Tracking calculation with ASTRA show,that this perturbation increases the transversel emittance between 1 and 4%, nearly independent from the bunch charge. This result shows, that for average beam powers in the vicinity of 10kW effects, connected with the assymetric input of RF power can be neglected.

MOPKF016	S2E Simulations on Jitter for European XFEL Project	simulation, gun, emittance, klystron	336
	Y. Kim, Y. Kim, D. Son CHEP, Daegu K. Floettmann, T. Limberg DESY, Hamburg
	In order to generate stable 0.1 nm wavelength SASE source at the European X-ray laser project XFEL, we should supply high quality electron beams with constant beam characteristics to a 200 m long undulator. Generally, beam parameters such as peak current and energy spread are significantly dependent on jitter or error in RF phase and RF amplitude of superconducting accelerating modules, and magnetic field error of bunch compressors. In this paper, we describe the start-to-end simulations from the cathode to the end of linac to determine the jitter and error tolerances for the European XFEL project.

MOPKF017	New Simulations on Microbunching Instability at TTF2	cathode, simulation, space-charge, damping	339
	Y. Kim, Y. Kim, D. Son CHEP, Daegu K. Floettmann DESY, Hamburg
	Microbunching instability in the FEL driver linac can be induced by collective self-fields such as longitudinal space charge, coherent synchrotron radiation, and geometric wakefields. In this paper, we describe the first start-to-end simulations including all important collective self-fields from the cathode to the end of TTF2 linac with 1.5 million macroparticles.

MOPKF018	Injector and Bunch Compressor for the European XFEL Project	emittance, space-charge, gun, simulation	342
	Y. Kim, Y. Kim, D. Son CHEP, Daegu M. Dohlus, K. Floettmann, T. Limberg DESY, Hamburg
	For the proper operation of European XFEL project, we should supply high quality electron beams with low emittance, short bunch length, and low energy spread to a 200 m long undulator. In this paper, we describe the optimization and design concepts of the XFEL injector and bunch compressors to control the beam parameter dilution due to the microbunching instability and CSR.

MOPKF030	"ARC-EN-CIEL" a Proposal for a 4th Generation Light Source in France	laser, radiation, gun, electron	366
	M.-E. Couprie, D. Garzella, B. Gilquin, P. Monot, L. Nahon CEA/DSM, Gif-sur-Yvette O.V. Chubar, A. Loulergue SOLEIL, Gif-sur-Yvette M. Desmons, M. Jablonka, F. Meot, A. Mosnier CEA/DSM/DAPNIA, Gif-sur-Yvette J.-R. Marquès LULI, Palaiseaux J.-M. Ortega LURE, Orsay A. Rousse LOA, Palaiseau
	An accelerator based 4th generation source is proposed to provide the user community with coherent femtosecond light pulses in the UV to X ray range. The project is based on a CW 700 MeV superconducting linac delivering high charge, subpicosecond, low emittance electron bunches with high repetition rate. This facility allows for testing High Gain Harmonic Generation seeded with high harmonics in gases, as well as the standard SASE mode, covering a spectral range down to 0.8 nm and 5 nm respectively. In addition, two beam loops are foreseen to increase the beam current in using the energy recovery technique. They will accommodate undulators for the production of femtosecond synchrotron radiation in the IR, VUV and X ray ranges together with a FEL oscillator in the 10 nm range.

MOPKF033	Operational Improvements in the ESRF Injection Complex	injection, booster, emittance, quadrupole	375
	Y. Papaphilippou, P. Elleaume, L. Farvacque, L. Hardy, G.A. Naylor, E. Plouviez, J.-L. Revol, B.K. Scheidt, V. Serriere ESRF, Grenoble
	The ESRF injection complex, comprising a 200MeV linac, a booster accelerator with a top energy of 6GeV and two transfer lines, has been routinely injecting beam to the storage ring since the beginning of its operation. The newly implemented injection with ‘‘front-end open'' triggered several operational improvements in order to maximise the reliability of the complex. A series of diagnostics (sychnotron light monitors, striplines, fast current transformers) were implemented allowing the measurement and monitoring of several components of the injected beam. New optics models were constructed and several application systems as the closed orbit correction or tune measurements have been upgraded. The operational procedures of injection at 100MeV in the booster and the injection efficiency maximisation were renewed and improved. Further developments for the uninterrupted operation of the storage ring during injection, such as the bunch cleaning in the booster were successfully tested.

MOPKF037	FERMI@ELETTRA: 100 nm - 10 nm Single Pass FEL User Facility	undulator, electron, radiation, laser	387
	R.J. Bakker, C. Bocchetta, P. Craievich, G. D'Auria, M. Danailov, G. De Ninno, S. Di Mitri, B. Diviacco, G. Pangon, L. Rumiz, L. Tosi, V. Verzilov, D. Zangrando ELETTRA, Basovizza, Trieste
	The FERMI@ELETTRA project is an initiative from ELETTRA, INFM and other Italian institutes, to construct a single-pass FEL user-facility for the wavelength range from 100 nm (12 eV) to 10 nm (124 eV), to be located next to the third-generation synchrotron radiation facility ELETTRA in Trieste, Italy. The project is concentrated around the existing 1.2-GeV S-band linac, i.e., the injector for the storage ring. Presently the linac is only operational for approximately 2 hours per day. The remaining time is available for the construction and operation of an FEL but modifications and operation must be planned such that operation of the storage ring can be guaranteed until the completion of a new full-energy injector (spring 2006). At this moment the FEL project evolves from a conceptional design stage towards a technical design and the actual implementation. Key issues are: incorporation of the free-electron laser in the infrastructure of the Sincrotrone Trieste, adjustments of the linac to facilitate FEL operation, required additional civil engineering, undulator design, FEL seeding options, and beamline design. This paper serves as an overview of the project in combination with a discussion of the critical issues involved.

MOPKF041	SPARC Photoinjector Working Point Optimization, Tolerances and Sensitivity to Errors	emittance, undulator, simulation, gun	396
	M. Ferrario, M.E. Biagini, M. Boscolo, V. Fusco, S. Guiducci, M. Migliorati, C. Sanelli, F. Tazzioli, C. Vaccarezza INFN/LNF, Frascati (Roma) L. Giannessi, L. Mezi, M. Quattromini, C. Ronsivalle ENEA C.R. Frascati, Frascati (Roma) J. Rosenzweig UCLA, Los Angeles, California L. Serafini INFN-Milano, Milano
	A new optimization of the SPARC photoinjector, aiming to reduce the FEL saturation length, is presented in this paper. Start to end simulations show that with 1.1 nC charge in a 10 ps long bunch we can deliver at the undulator entrance a beam having 100 A in 50% of the slices (each slice being 300 mm long) with a slice emittance ?1 mm, thus reducing the FEL-SASE saturation length to 12 m at 500 nm wavelength. In addition the stability of the nominal working point and its sensitivity to various type of random errors, under realistic conditions of the SPARC photoinjector operation, are discussed. A systematic scan of the main parameters around the operating point, performed with PARMELA code interfaced to MATLAB, shows that the probability to get a projected emittance exceeding 1 mm is only 10 % and the slice emittance remains below 1 mm in all cases.

MOPKF042	Status of the SPARC Project	laser, undulator, emittance, gun	399
	M. Ferrario, D. Alesini, M. Bellaveglia, S. Bertolucci, M.E. Biagini, R. Boni, M. Boscolo, M. Castellano, A. Clozza, G. Di Pirro, A. Drago, A. Esposito, D. Filippetto, V. Fusco, A. Gallo, A. Ghigo, S. Guiducci, M. Incurvati, C. Ligi, F. Marcellini, L. Pellegrino, M.A. Preger, R. Ricci, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stecchi, A. Stella, F. Tazzioli, C. Vaccarezza, M. Vescovi, C. Vicario INFN/LNF, Frascati (Roma) F. Alessandria, A. Bacci, M. Mauri INFN/LASA, Segrate (MI) I. Boscolo, F. Brogli, S. Cialdi, C. De Martinis, D. Giove, C. Maroli, V. Petrillo, M. Romé, L. Serafini INFN-Milano, Milano L. Catani, E.C. Chiadroni, A. Cianchi, S. Tazzari Università di Roma II Tor Vergata, Roma F. Ciocci, G. Dattoli, A. Doria, F. Flora, G.P. Gallerano, L. Giannessi, E. Giovenale, G. Messina, L. Mezi, P.L. Ottaviani, L. Picardi, M. Quattromini, A. Renieri, C. Ronsivalle ENEA C.R. Frascati, Frascati (Roma) D. Dowell, P. Emma, C. Limborg-Deprey, D. Palmer SLAC, Menlo Park, California D. Levi, M. Mattioli, G. Medici Università di Roma I La Sapienza, Roma M. Migliorati, A. Mostacci, L. Palumbo Rome University La Sapienza, Roma P. Musumeci, J. Rosenzweig UCLA, Los Angeles, California M. Nisoli, S. Stagira, S. de Silvestri Politecnico/Milano, Milano
	The aim of the SPARC project is to promote an R&D activity oriented to the development of a high brightness photoinjector to drive SASE-FEL experiments at 500 nm and higher harmonics generation. It has been proposed by a collaboration among ENEA-INFN-CNR-Universita‘ di Roma Tor Vergata-INFM-ST and funded by the Italian Government with a 3 year time schedule. The machine will be installed at LNF, inside an existing underground bunker. It is comprised of an rf gun driven by a Ti:Sa laser to produce 10-ps flat top pulses on the photocathode, injecting into three SLAC accelerating sections. We foresee conducting investigations on the emittance correction and on the rf compression techniques up to kA level. The SPARC photoinjector can be used also to investigate beam physics issues like surface-roughness-induced wake fields, bunch-length measurements in the sub-ps range, emittance degradation in magnetic compressors due to CSR. We present in this paper the status of the design activities of the injector and of the undulator. The first test on diagnostic prototypes and the first experimental achievements of the flat top laser pulse production are also discussed.

MOPKF044	Wake Fields Effects in the Photoinjector of the SPARC Project	emittance, space-charge, impedance, optics	405
	V. Fusco, M. Ferrario, B. Spataro INFN/LNF, Frascati (Roma) M. Migliorati, L. Palumbo Rome University La Sapienza, Roma
	When a bunch travels off axis across structures whose shape is not uniform, such as RF cavity or bellows, generates longitudinal and transverse wake fields. In addition transverse time dependent fields (like transverse RF components and wake fields ) may induce correlated slice centroids displacement, so that each slice centroid motion become affected also by space charge forces generated by the next slices. An evaluation of the emittance degradation and induced energy spread in the SPARC injector is performed with an improved version of the code Homdyn and the results are discussed. A comparison with other codes (ABCI, PARMELA 3D) to validate our model is also presented.

MOPKF046	Photoelectron RF Gun Designed as a Single Cell Cavity	gun, emittance, cathode, electron	411
	H. Dewa, T. Asaka, H. Hanaki, T. Kobayashi, A. Mizuno, S. Suzuki, T. Taniuchi, H. Tomizawa, K. Yanagida JASRI/SPring-8, Hyogo J. Sasabe Hamamatsu Photonics K.K., Hamakita, Shizuoka M. Uesaka UTNL, Ibaraki
	The paper describes the recent improvements of S-band RF-gun at SPring-8. The cavity of the gun is a single-cell pillbox, and the copper inner wall is used as a cathode. The electron beam from the cathode was accelerated up to 4.1 MeV at an electric field of 175 MV/m. For emittance compensation, two solenoid magnets were used. A 3m linac and a quadrupole scan emittance diagnostic were added after the RF-gun. The beam energy spread and beam emittance after the linac is presented. The beam emittance measured with quadrupole scan is compered to that measured with double slits just after the RF-gun. For high quantum efficiency, Cs2Te cathode was also tested. It is vacuum sealed in a cartridge-type electric tube and four tubes can be installed in a vacuum chamber behind the cavity. Although the quantum efficiency after RF conditioning for two hours to achieve 90MV/m was 3%, it decreased to 1% after the 28 hours RF conditioning.

MOPKF049	Design Study for a 205 MeV Energy Recovery Linac Test Facility at the KEK	optics, emittance, dipole, simulation	420
	E.-S. Kim PAL, Pohang K. Yokoya KEK, Ibaraki
	We present a lattice and beam dynmics analysis for a 200 MeV energy recovery linac test facility at the KEK. The test facility consists of a photocathode rf gun, a 5 MeV injector, a merger, 200 MeV superconducting linac, TBA sections and beam dump line. Beam parameters and optimal optics to relaize the energy recovery linac are described. Simulation results on emittance growth due to HOMs in the superconducting linac and coherent synchrotron radiation in the designed lattice are presented.

MOPKF054	Generation of Femtosecond Electron Pulses	electron, cathode, simulation, radiation	431
	S. Rimjaem, V. Jinamoon, K. Kusoljariyakul, J. Saisut, C. Thongbai, T. Vilaithong FNRF, Chiang Mai S. Chumphongphan Mae Fah Luang University, Chiang Rai M.W. Rhodes, P. Wichaisirimongkol IST, Chiang Mai H. Wiedemann SLAC/SSRL, Menlo Park, California
	Femtosecond electron pulses have become an interesting tool for basic and applied applications, especially in time-resolved experiments and dynamic studies of biomolecules. Intense, coherent radiation can be generated in a broad far-infrared spectrum with intensities, which are many orders of magnitude higher than conventional sources including synchrotron radiation sources. At the Fast Neutron Research Facility (FNRF), Chiangmai University (Thailand), the SURIYA project has been established with the aim to produce femtosecond pulses utilizing a combination of a S-band thermionic rf-gun and an alpha-magnet as the magnetic bunch compressor. A specially designed rf-gun has been constructed to obtain the optimum beam characteristics for best bunch compression. Simulation results show that the bunch lengths as short as 50 fs rms can be expected at the experimental station. This rf- gun, an alpha-magnet and a 20 MeV linac with beam transport system were installed and are being commissioned to generate femtosecond electron bunches. To measure the bunch length of the electron pulses, a Michelson interferometer will be used to observe the spectrum of coherent FIR transition radiation via optical autocorrelation. The main results of numerical simulations and experimental results will be discussed in this paper.

MOPKF059	Magnet Specification for the Daresbury Laboratory Energy Recovery Linac Prototype	dipole, quadrupole, booster, injection	443
	N. Thompson, N. Marks CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
	Daresbury Laboratory has funding for the design and construction of an Energy Recovery Linac (ERL) prototype to facilitate the R&D necessary for the 4th Generation Light Source (4GLS). In the prototype a 35MeV electron beam will be used to drive an Infra-Red Oscillator Free-Electron Laser. The ring consists of two 180°; triple bend achromats, two straight sections, an injection chicane, an extraction chicane and two bunch compression/decompression chicanes. A number of pre-existing magnets will be used in the ring so the new magnets have been designed to ensure compatibility with the existing designs, enabling common power supply, vacuum and control system specifications. This paper gives an overview of the magnet requirements for the facility and details of the engineering realisation.

MOPKF060	Space Charge Effects for the ERL Prototype at Daresbury Laboratory	emittance, space-charge, quadrupole, focusing	446
	B.D. Muratori, C. Gerth CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire N. Vinokurov BINP SB RAS, Novosibirsk
	Daresbury Laboratory is currently building an Energy Recovery Linac Prototype (ERLP) that will operate at a beam energy of 35 MeV. In this paper we examine the Space Charge effects on the beam dynamics in the ERLP injector line. This is done in two distinct ways. The first is based on an analytic formula derived by Vinokurov through the envelope equations and a Kapchinsky-Vladimirsky (KV) distribution. This formula gives a rough estimate of the space charge effects in the case that no quadrupoles or dipoles are present in the injector line. The second estimate is given by the multi-particle tracking code ASTRA for the whole injector line both with and without quadrupoles. Both methods are compared and are found to be in good agreement. Typical examples of injector lines are given together with specific calculations for the ERLP.

MOPKF061	Optics Layout for the ERL Prototype at Daresbury Laboratory	electron, extraction, injection, beam-transport	449
	B.D. Muratori, H.L. Owen, J.A. Varley CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
	The overall optics for the Energy Recovery Linac Prototype (ERLP) at Daresbury Laboratory is summarised. This includes the layout of the injector line, all chicanes used, as well as details of both the outward and return TBA arcs. The tunability in several sections of the machine is examined under different operational modes and starting parameters from the end of the booster to the dump.

MOPKF062	Choice of Arc Design for the ERL Prototype at Daresbury Laboratory	dipole, quadrupole, sextupole, beam-transport	452
	H.L. Owen, B.D. Muratori CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
	The choice of arc design for the Energy Recovery Linac Prototype (ERLP) to be built at Daresbury Laboratory is investigated. Both the overall merits and disadvantages of a TBA arc and Bates bend are considered, and space restrictions particular to Daresbury Laboratory given. Some magnet parameters are given together with a summary of the layout of the ERLP.

MOPKF063	4GLS and the Prototype Energy Recovery Linac Project at Daresbury	gun, electron, booster, brightness	455
	M.W. Poole, E.A. Seddon CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
	The 4GLS project is a novel next generation solution for a UK national light source proposed to be sited at Daresbury. It is based on an energy recovery linac (ERL) operating at high average beam currents up to 100mA and with compression schemes producing pulses in the 10^-100 fs range. This would provide a unique spontaneous emission source with high average brightness output both from undulators and bending magnets. In addition to this operating regime a high peak current mode would also be possible at lower duty cycle, enabling a high gain FEL amplifier to generate XUV radiation. Longer wavelength FELs are also planned. This challenging accelerator technology, new to Europe, necessitates a significant R&D programme and as a major part of this a low energy prototype, the ERLP, is being constructed at Daresbury. The paper summarises the ERLP design specification, describes the component solutions adopted and explains the 4GLS project status and plans.

MOPKF067	Comparison of Different Buncher Cavity Designs for the 4GLS ERLP	gun, higher-order-mode, emittance, space-charge	467
	E. Wooldridge, C.D. Beard, C. Gerth CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire A. Buechner FZR/FWFE, Dresden
	A DC photocathode gun is part of the injector of the Energy Recovery Linac Prototype (ERLP) currently built at Daresbury Laboratory. A buncher is required for the ERLP to decrease the bunch length off the gun. Three different single-cell cavity designs were investigated: The Cornell buncher, the Elbe Buncher and an EU cavity without Higher Order Mode (HOM) dampers. The properties of these cavities were studied with the computer codes CST's Microwave Studio and ASTRA. The fundamental frequency and field pattern was investigated in Microwave Studio. The EU cavity had to be scaled from 500MHz as the required frequency for the buncher is 1.3GHz. As the anticipated kinetic energy of the electron beam after the gun is about 350keV a particle tracking code including the space charge forces is mandatory to study the effect of the different buncher cavity designs on the beam dynamics. The particle tracking code ASTRA was used to study the performance of the bunchers for a variety of beam parameters. From these investigations it was found that the three bunchers produce very similar effects on the particle bunch.

MOPKF070	Design of Injector Systems for LUX	emittance, gun, cathode, quadrupole	476
	S.M. Lidia LBNL/AFR, Berkeley, California
	The LUX concept [1] for a superconducting recirculating linac based ultrafast x-ray facility features a unique high-brightness electron beam injector. The design of the injector complex that meets the baseline requirements for LUX are presented. A dual-rf gun injector provides both high-brightness electron beams to drive the cascaded, seeded harmonic generation VUV-soft x-ray FELs as well as the ultra- low-vertical emittance ('flat') beams that radiate in hard x-ray spontaneous emission synchrotron beamlines. Details of the injector complex design and performance characteristics are presented. Contributions by the thermal emittance and optical pulse shaping to the beam emission at the photocathode and to the beam dynamics throughout the injector are presented. Techniques that seek to optimize the injector performance, as well as constraints that prevent straightforward optimization, are discussed.

MOPKF076	An Overview of the Cryomodule for the Cornell ERL Injector	emittance, coupling, damping, synchrotron	491
	H. Padamsee, B.M. Barstow, V. Medjidzade, V.D. Shemelin, K.W. Smolenski Cornell University, Ithaca, New York I. Bazarov, C.K. Sinclair Cornell University, Department of Physics, Ithaca, New York S.A. Belomestnykh, R. Geng, M. Liepe, M. Tigner, V. Veshcherevich Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
	The first stage of the Cornell ERL project will be a 100 MeV, 100 mA (CW) prototype machine to study the energy recovery concept with high current, low emittance beams. In the injector, a bunched 100 mA, 500 keV beam of a DC gun will be compressed in a normal-conducting copper buncher and subsequently accelerated by five superconducting 2-cell cavities to an energy of 5.5 MeV. We will present an overview of the injector status to include the status of the cryomodule design along with the status of the 2-cell HOM-free cavity, the twin-input coupler and the ferrite HOM dampers in related papers.

MOPKF077	Reducing the Synchrotron Radiation on RF Cavity Surfaces in an Energy-recovery Linac	radiation, synchrotron, synchrotron-radiation, electron	494
	G. Hoffstaetter, M. Liepe, T. Tanabe Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
	In Energy Recovery Linac (ERL) light sources, a high energy, high current beam has to be bend into a superconducting linac to be decelerated. The synchrotron radiation produced in the last bending magnet before the linac shines into the superconducting structures if not collimated appropriately. Due to the length of the linac, the radiation cannot be completely guided through the superconducting structure, as in existing SRF storage rings. For the example of an ERL extension to the existing CESR storage ring at Cornell we estimate the magnitude of this problem by quantifying the heat load that can be accepted on a superconducting surface and by analyzing how much radiation is deposited on the cavity surfaces for different collimation schemes.

MOPKF078	ERL Upgrade of an Existing X-ray Facility: CHESS at CESR	electron, emittance, optics, undulator	497
	G. Hoffstaetter, M. Liepe, R.M. Talman, M. Tigner Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York I. Bazarov, H. Bilderback, M. Billing, S. Gruner, D. Sagan, C.K. Sinclair Cornell University, Department of Physics, Ithaca, New York
	CORNELL has proposed an Energy-Recovery Linac (ERL) based synchrotron-light facility which can provide improved x-ray radiation due to the high beam quality that can be available from a linac. To additionally utilize beam currents that are competitive with ring-based light sources, the linac has to operate with the novel technique of energy recovery, the feasibility of which CORNELL plans to demonstrate in a downscaled prototype ERL. Here we present an ERL upgrade of the existing 2nd generation light source CHESS at CESR. This proposed upgrade suggests how existing storage rings can be extended to ERL light sources with much improved beam qualities.

MOPKF079	The Linac Coherent Light Source Photo-Injector Overview and Some Design Details	gun, cathode, emittance, dipole	500
	D. Dowell, R. Akre, L.D. Bentson, P. Bolton, R.M. Boyce, R. Carr, J.E. Clendenin, S.M. Gierman, A. Gilevich, K. Kotturi, Z. Li, C. Limborg-Deprey, W. Linebarger, M. Ortega, J. Schmerge, P. Smith, L. Xiao SLAC, Menlo Park, California
	The Linac Coherent Light Source (LCLS)[] is a SASE free electron laser using the last 1/3 of the SLAC two mile linac to produce 1.5 to 15 angstrom x-rays in a 100 meter long undulator. A new 135 MeV photo-injector will be built in an existing, off-axis vault at the 2/3 point of the main linac. The injector accelerator consists of a BNL/SLAC/UCLA s-band gun followed by two 3-meter long SLAC accelerator sections. The 5.6 MeV beam from the gun is matched into the first accelerator section and accelerated to 135 MeV before injection onto the main linac axis with a 35 degree bend []. Several modifications have been made to the rf gun, linac and beamline as well as the inclusion of several diagnostics have been incorporated into the injector design to achieve the required 1.2 micron projected emittance at a charge of 1 nC. In addition, a laser heater [], will increase the uncorrelated energy spread to suppress coherent synchrotron radiation and longitudinal space charge instabilities in the main accelerator and bunch compressors [*]. The configuration and function of the major injector components will be described. Linac Coherent Light Source (LCLS) CDR No. SLAC-R-593 UC-414, 2002 C. Limborg et al., Proc. of the 2003 International FEL Conf * R. Carr et al, Contrib. to these proceedings **** Z. Huang et al., Contrib. to these proceedings

MOPKF081	Peak Current Optimization for LCLS Bunch Compressor 2	undulator, emittance, simulation, damping	506
	A.C. Kabel, P. Emma SLAC, Menlo Park, California
	The performance of an FEL will be a function of both the driving bunch's current and its slice emittance. We have studied a set of parameters for the bunch compression section of the LCLS, simulating the effects of Coherent Synchrotron Radiation (CSR) on the slice emittance of the bunch core as a function of peak current. We use the code TraFiC4 for a three-dimensional, self-consistent simulation on parallel computers. While higher currents will increase FEL performance, its detrimental effects, due to CSR, on slice emittance will counteract this beneficial effect. From our simulations, we determine a near-optimum current, balancing these effects.

MOPKF083	Inverse Free Electron Laser Heater for the LCLS	laser, electron, undulator, gun	512
	R. Carr, L.D. Bentson, P. Bolton, D. Dowell, P. Emma, A. Gilevich, Z. Huang, J.J. Welch, J. Wu SLAC, Menlo Park, California
	The LCLS Free Electron Laser employs an RF photocathode gun that yields a 1 nC charge bunch a few picoseconds long, which must be further compressed to yield the high current required for SASE gain. The very cold electron beam from the RF photocathode gun is quite sensitive to microbunching instabilities such as coherent synchrotron radiation (CSR) in the compressor chicanes and longitudinal space charge (LSC) in the linac. These effects can be Landau damped by adding energy spread to the electron bunch prior to compression. We propose to do this by interacting an infrared laser beam with the electron bunch in an undulator added to the LCLS gun-to-linac injector. The undulator is placed in a 4-bend chicane to allow the IR laser beam to propagate co-linearly with the e-beam while it oscillates in the undulator. The IR laser beam is derived from the photocathode gun laser. Simulations presented elsewhere in these proceedings show that the laser interaction damps the microbunching instabilities to a very great extent. This paper is a description of the implementation of the laser heater

MOPKF085	Design Optimizations of X-ray FEL Facility at MIT	electron, laser, simulation, gun	518
	D. Wang, M. Farkhondeh, W. Graves, J. Van der Laan, F. Wang, T. Zwart MIT/BLAC, Middleton, Massachusetts P. Emma SLAC, Menlo Park, California
	MIT is exploring the construction of a linac-based x-ray laser user facility on the campus of the Bates Linear Accelerator Center. The facility under consideration would span the wavelength range from 100 to 0.3 nm in the fundamental, move into the hard X-ray region in the third harmonic, and preserve the possibility of an upgrade to even shorter wavelengths. The accelerator configuration would include a high brightness electron gun, a superconducting electron linac and multiple undulators and beam lines to support a growing user community. This paper will present the recent progress on the start-to-end simulations including the parameter optimizations and sensativity analysis.

MOPKF086	Modifications of the LCLS Photoinjector Beamline	emittance, laser, gun, quadrupole	521
	C. Limborg-Deprey, D. Dowell, S.M. Gierman SLAC, Menlo Park, California
	The LCLS Photoinjector beamline is now in the Design and Engineering stage. The fabrication and installation of this beamline is scheduled for the summer 2006. The Photoinjector will deliver 10 ps long electron bunches of 1nC with a normalized transverse emittance of less than 1 mm.mrad for 80% of the slices constituting the core of the bunch at 135 MeV. In this paper, we describe some modifications of the beamline: new exit energy, additional focusing, insertion of a laser heater. We also describe an alternate tuning which is based on a laser pulse of 20ps. The advantages and drawbacks of this long pulse tuning are reviewed. A comparison of sensitivity to field errors and misalignment between the long pulse tuning and the nominal tuning is given.

MOPKF087	The Cebaf Energy Recovery Experiment: Update and Future Plans	injection, emittance, optics, diagnostics	524
	A. Freyberger, K. Beard, S.A. Bogacz, Y.-C. Chao, S. Chattopadhyay, D. Douglas, A. Hutton, L. Merminga, C. Tennant, M. Tiefenback Jefferson Lab, Newport News, Virginia
	A successful GeV scale energy recovery demonstration with a high ratio of peak-to-injection energies (50:1) was carried out on the CEBAF (Continuous Electron Beam Accelerator Facility) recirculating superconducting linear accelerator in the spring 2003. To gain a quantitative understanding of the beam behavior through the machine, data was taken to characterize the 6D phase space during the CEBAF-ER (CEBAF with Energy Recovery) experimental run. The transverse emittance and energy spread of the accelerating and energy recovered beams were measured in several locations to ascertain the beam quality preservation during energy recovery. Measurements also included the RF system's response to the energy recovery process and transverse beam profile of the energy recovered beam. One of the salient conclusions from the experiment is that the energy recovery process does not contribute significantly to the emittance degradation. The current status of the data analysis will be presented as well as plans for a GeV scale energy recovery experimental run with current doubling.

MOPLT003	Upgrading the LNLS Control System from a Proprietary to a Commercial Communications Environment	power-supply, target, monitoring, feedback	530
	J.G.R.S. Franco, R.M. Ernits, M. Fernandes, A.F.A. Gouveia, J.R. Piton, M.A. Raulik, F.D.S. Rodrigues LNLS, Campinas
	The LNLS Control System was built over a proprietary technology, due to governmental policy of information technology in the mid 80's. This made interfacing to commercial systems difficult, limited the technology transfer to the private sector, required a staff with specific knowledge and reduced the possibility of new implementations on the system. Nowadays, the cost to move all of our hardware to a commercial one is out of our budget. This paper describes a proposal, the viability study and first results to move only the communication interfaces to a commercial environment, keeping most of our hardware unchanged and opening the way to gradually move the system to widely accepted standards, when and if necessary. This solution allows a smooth implementation without long periods of machine shutdown and keeps the possibility to operate the machine concurrently between old and new communication interfaces.

MOPLT007	Base Line Design for a Beta-beam Neutrino Facility	ion, acceleration, injection, target	542
	M. Benedikt, S. Hancock, M. Lindroos CERN, Geneva
	The term beta-beam has been coined for the production of pure beams of electron neutrinos or their antiparticles through the decay of radioactive ions circulating in a storage ring. The neutrino source itself consists of a high energy storage ring (gamma ~150), with long straight sections in line with the experiment(s). The radioactive ions (6He and 18Ne) will be produced in an ISOL type target system. Due to the short life times of around 1s at rest, the beam needs to be accelerated as quickly as possible. For this a staged system of accelerators is proposed. The chain starts with a linac followed by a rapid cycling synchrotron for acceleration up to ~300 MeV/u. For further acceleration the existing PS and SPS machines are used. Finally, after acceleration to SPS top energy, the ions are transferred to the decay ring where they are merged with the already circulating bunch through a longitudinal stacking procedure. The base line design of the beta beam facility will be presented and the major design problems encountered as well possible solutions will be discussed.

MOPLT013	Fatigue Testing of Materials by UV Pulsed Laser Irradiation	laser, simulation, vacuum, radiation	557
	S. Calatroni, H. Neupert, M. Taborelli CERN, Geneva
	The energy dissipated by the RF currents in the cavities of high-power pulsed linacs induces cycles of the surface temperature. In the case of the CLIC main linac the expected amplitude of the thermal cycles is about hundred degrees, for a total number of pulses reaching 10e11. The differential thermal expansion due to the temperature gradient in the material creates a cyclic stress that can result in surface break-up by fatigue. The materials for cavity fabrication must therefore be selected in order to withstand such constraints whilst maintaining an acceptable surface state. The fatigue behaviour of Cu and CuZr alloy has been tested by inducing larger surface peak temperatures, thus reducing the number of cycles to failure, irradiating the surface with 50 ns pulses of UV light (308 nm) from an excimer laser. Surface break-up is observed after different number of laser shots as a function of the peak temperature. CuZr appears to withstand a much larger number of cycles than Cu, for equal peak temperature. The characterization of the surface states and possible means of extrapolating the measured behaviour to the expected number of pulses of CLIC are discussed in detail.

MOPLT028	In-Situ Vibration Measurements of the CTF2 Quadrupoles	quadrupole, resonance, alignment, lattice	602
	S. Redaelli, W. Coosemans CERN, Geneva
	The Compact LInear Collider (CLIC), presently under study at the European Organization for Nuclear Research (CERN), aims at colliding high-energy ‘‘nanobeams'' at a luminosity of 10$³⁵$\,cm^-2s^-1. Vibrations of the lattice elements, if not properly corrected, can result in a loss in performance by creating both unacceptable emittance growth in the linear accelerator and relative beam-beam offsets at the interaction point. Of particular concern are the vibrations induced by the accelerator environment. For example, the circulating water used to cool the lattice quadrupoles will increase magnet vibration levels. In the framework of the CLIC stability study, in-situ measurements of quadrupole vibrations have been performed at the CLIC Test Facility 2 (CTF2) with all accelerator equipment switched on. Since the CTF2 quadrupoles and their alignment support structures are realistic prototypes of those to be used in the CLIC linac, the measurements provide a realistic estimate of the CLIC magnet vibrations in a realistic accelerator working environment.

MOPLT029	All Digital IQ Servo-system for CERN Linacs	heavy-ion, diagnostics, ion, controls	605
	A. Rohlev, J. Broere, R. Garoby, I. Kozsar, J. Serrano CERN, Geneva
	A VME based control system has been developed and built at CERN for the servo loops regulating the field in linac accelerating structures. It is an all-digital system built on a single VME card, providing digital detection, processing, and modulation. It is foreseen to be used, in different versions, for the needs of both present and future CERN hadron linacs. The first application will be in the energy ramping RF chain of the CERN Heavy Ion Linac (linac 3). In addition to regulating the cavity field, the system incorporates the measurement and control of the cavity resonance as well as an imbedded loop stabilizing the gain and the phase of the final amplifier operating near saturation. The design principle and the experimental results are described.

MOPLT040	Test Results of Superconducting Cavities Produced and Prepared Completely in Industry	vacuum, pick-up, superconductivity, cathode	635
	M. Pekeler, S. Bauer, B. Griep, H.P. Vogel, P. vom Stein ACCEL, Bergisch Gladbach
	Superconducting cavities for a variety of recent projects are produced and prepared for operation in industry. We report on test results of those cavities produced and prepared at ACCEL. The preparation of the cavities includes chemical treatment (BCP), rinsing with high pressure water and assembly in a clean room. The following cavity types were treated: 400 MHz single cell cavities for LHC, 500 MHz single cell cavities of the Cornell CESR design for our superconducting accelerating modules, 1300 MHz TESLA type cavities, 176 MHz and 160 MHz halfwave resonators and a 352 MHz CH-mode cavity for ion accelaration.

MOPLT058	Status of CTF3 Stretcher-compressor and Transfer Line	vacuum, dipole, synchrotron, synchrotron-radiation	686
	A. Ghigo, D. Alesini, C. Biscari, A. Clozza, A. Drago, A. Gallo, F. Marcellini, C. Milardi, B. Preger, M.A. Preger, C. Sanelli, M. Serio, F. Sgamma, A. Stecchi, A. Stella, M. Zobov INFN/LNF, Frascati (Roma) R. Corsini, G. Geschonke CERN, Geneva
	The first part of the CTF3 transfer line is under installation. It includes a chicane which, because of its very flexible lattice and large aperture vacuum chamber, can change the bunch length in a wide range. The chicane can be used as a stretcher to lengthen the pulses coming from the linac in order to reduce the coherent synchrotron radiation (CSR) in the recombination rings. A possible use as a bunch compressor is also foreseen in order to make CSR experiments and to characterize beam instrumentation. This paper describes the final design of the vacuum chambers, including beam diagnostics components, and their laboratory tests. The installation status of the magnetic and vacuum chamber components together with the ancillary systems is reported.

MOPLT059	Design Options for the RF Deflector of the CTF3 Delay Loop	klystron, simulation, coupling, polarization	689
	F. Marcellini, D. Alesini INFN/LNF, Frascati (Roma)
	Injection and extraction of bunch trains in the CTF3 Delay Loop for the recombination between adjacent bunch trains is performed by a specially designed RF deflector. A standing wave structure has been chosen. Three possible solutions have been studied and designed, and a comparative analysis is presented. All of them satisfy the essential requirements of the system up to the maximum foreseen energy with the existing klystron.

MOPLT066	Induction Accelerating Cavity for a Circular Ring Accelerator	induction, acceleration, synchrotron, proton	704
	K. Torikai, Y.A. Arakida, T. Kono, K. Koseki, E. Nakamura, Y. Shimosaki, K. Takayama, T. Toyama, M. Wake KEK, Ibaraki J. Kishiro JAERI/LINAC, Ibaraki-ken
	This paper reports details of an induction accelerating cavity employed for induction synchrotron POP experiments [] using the KEK 12GeV PS. This cavity is the first induction cavity in the history of accelerator that is used in a circular ring. We focus our attention on crucial aspects distinguished from well-know properties of RF cavity. The single cavity is capable of generating an acceleration voltage of 2.5kV with a pulse width of 250ns, which is operated at a repetition　rate in the range of 667kHz - 882kHz. The cavity is driven by its own pulse modulator through a 25m long transmission cable of 125W, the end of which is connected with a matching resistance so as to minimize reflection in a wide range of frequency. Accelerating field characteristics are discussed and matching features of the cavity as a one-to-one transformer are presented. A longitudinal and transverse coupling impedance have been measured using a net-work analyzer. K.Takayama et al., 'POP Experiments of the Induction Synchrotron' in this conference

MOPLT071	EPICS Based Control System for the KOMAC RF System	proton, rfq, feedback, vacuum	716
	J.C. Yoon, J. Choi, K.M. Ha, J.H. Kim, J.M. Kim, J.-W. Lee PAL, Pohang
	This paper presents the RF control system for Korea Multi-purpose Accelerator Complex (KOMAC). KAERI (Korea Atomic Energy Research Institute) has been performing the project named KOMAC. As the 3nd phase of the project, 20MeV proton accelerating structure is under development. The new design is based on the use of VME based Multi-function modules connected to the specific low level RF Controllers(LLRF) via distributed I/O modules and Serial communication modules. The control system was based on EPICS (Experimental Physics and Industrial Control System) from the end of 2003. Installation and commissioning of the RF module is scheduled on 2004. Control system to integrated the RF System to the KOMAC control system is implemented. Hardware, software and various applications are developed to support the operation of RF Control system. This paper EPICS based control system for KOMAC RF

MOPLT081	Low Energy Ion Beam Dynamics in Axisymmetric RF Undulator Linac	focusing, ion, undulator, acceleration	731
	E.S. Masunov, S.M. Polozov MEPhI, Moscow
	The ion beam focusing and acceleration in an axisymmetric periodic RF undulator structure is considered. There is suggested that RF field has no a synchronous wave and accelerating force is to be driven by a combination of two non-synchronous waves. The influence of non-synchronous harmonics on ion beam dynamics is studied by means of a smooth approximation. Choice and optimization of RF field harmonics are made to obtain maximal transmission coefficient. The result is verified by a numerical simulation. The comparison with a conventional RF linac, where a synchronous harmonic accelerates a beam and non-synchronous one is focusing a beam, is described. This comparison is suitable for demonstration of the capabilities of an undulator linac.

MOPLT090	High Pulse and Average Power Low-induction Load	injection, damping, extraction, storage-ring	746
	F.V. Podgorny, B.I. Grishanov BINP SB RAS, Novosibirsk
	A high pulse and average power low-induction load with a built-in divider is described in this report. The load has a nominal resistance of 25 Ohm and is designed to operate with a repetition rate of up to 50 Hz at a pulse duration (FWHM) of 100 ns, a rise/fall time of 50 ns and a pulse amplitude of up to 40 kV. In this mode the dissipated energy is equal to about 8 J per pulse and average power is up to 400 W. The load can be used as an absorbing load and as a block element in high-voltage engineering.

MOPLT104	Quantitative Optimisation Studies of the Muon Front-End for a Neutrino Factory	lattice, target, emittance, proton	776
	S.J. Brooks CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
	In a Neutrino Factory, short proton pulses hit a target, producing pions at widely varying angles and energies. Efficient pion capture is required to maximise the yield of decayed muons, which proceed via acceleration stages into a muon storage ring to produce neutrinos. This paper presents optimisation of a solenoidal decay channel designed for high-emittance pions, based on schemes from CERN and RAL. A non-linear tracking code has been written to run under an optimisation algorithm where every beamline element can be varied, which is then deployed as a distributed computing project. Some subsequent stages of muon beamline are also simulated, including RF and non-RF phase-rotation techniques and in one option, initial muon acceleration to 400MeV. The objective is to find optimal transmissions for each front-end concept.

MOPLT108	TESLA Linac-IP Simulations	luminosity, feedback, simulation, ground-motion	788
	G.R. White Queen Mary University of London, London D. Schulte CERN, Geneva N.J. Walker DESY, Hamburg
	We have formulated integrated simulations of the transport of the electron and positron bunches in the Linear Collider from the linac entrance through the beam delivery system and the interaction region, taking wakefield effects into account. We have set up the simulations to run on the 64-cpu prototpye Grid cluster at QMUL and generated results for various sets of input parameters for the TESLA and NLC machines. For TESLA we have evaluated the distortion of the phase-space of the bunches at the interaction point due to wakefields. We have calculated the luminosity degradation and the production of photons and e⁺e^- pairs. We have simulated the performance of the intra-train beam feedback systems based on bunch position, angle and luminosity measures, and have evauated the luminosity recovery potential of these systems for TESLA and NLC.

MOPLT117	An Electron Front End for the Fermilab Multi-species 8 GeV SCRF Linac	electron, emittance, injection, laser	809
	P. Piot, G.W. Foster Fermilab, Batavia, Illinois
	Fermilab is considering 8 GeV superconducting linac whose primary mission is to serve as an intense H^- injector for the main injector. This accelerator is also planned to be used for accelerating various other species (e.g. electrons and muons). In the present paper we investigate the possibility of such a linac to accelerate a high brightness electron beam to ~7 GeV. We propose a design for the electron front end, based on a photoinjector, and consider the electron beam dynamics along the linac. Start-to-end simulations of the full accelerator for electrons are presented. Finally the potential applications of the such an electron beam are discussed.

MOPLT118	Muon Test Area at Fermilab	beam-cooling, booster, instrumentation, factory	812
	M. Popovic Fermilab, Batavia, Illinois
	A construction of a new experimental area designed to develop, test and verify muon ionization cooling using the 400- MeV Fermilab Linac proton beam was finished in fall of 2003. This area will be used initially for cryogenic tests of liquid-hydrogen absorbers for the MUCOOL R&D program and, later, for high-power beam tests of these absorbers and other prototype muon-cooling apparatus. The experimental scenarios being developed for muon facilities involve collection, capture, and cooling of large-emittance, high-intensity muon beams–~1013 muons at a repetition rate of 15Hz, so that conclusive tests of the apparatus require full Linac beam, or 1.6 x 1013 p at 15 Hz. The area has 12MW 805MHz, 5MW 201MHz RF, 4K Helium, 500W refrigeration and 400MeV H-/proton beam.

MOPLT121	Water Flow Vibration Effect on the NLC RF Structure-girder System	RF-structure, quadrupole, simulation, coupling	821
	C. Boffo, T.T. Arkan, E. Borissov, H. Carter Fermilab, Batavia, Illinois F. Le Pimpec, A. Seryi SLAC, Menlo Park, California
	In order to meet the vibration budget for the Next Linear Collider main Linac components, the vibration sources in the NLC girder are being studied. The activity is focused on the vibration induced by the cooling water flow for the 60 cm long accelerating copper structures. Understanding the vibration in the structures will enable us to push forward the design of the interface between the structures and the quadrupoles. This paper reports on the ongoing work and presents results from experimental data as well as finite element simulations.

MOPLT131	Emittance Dilution Simulations for Normal Conducting and Superconducting Linear Colliders	emittance, simulation, collider, damping	845
	R.M. Jones, T.O. Raubenheimer SLAC, Menlo Park, California N. Baboi DESY, Hamburg
	An electron (or positron) multi-bunch train traversing several thousand accelerator structures can be distorted by long-range wakefields left behind the accelerated bunches. These wakefields can at the very least, give rise to a dilution in the emittance of the beam and, at worst can lead to a beam break up instability. We investigate the emittance dilution that occurs for various frequency errors (corresponding to small errors made in the design or fabrication of the structure) for the GLC/NLC (Global Linear Collider/Next Linear Collider) and for TESLA (Terra Electron Superconducting Linear Accelerator). Resonant effects, which can be particularly damaging, are studied for X-band and L-band linacs. Simulations are performed with the computer codes LIAR[1] and L-MAFIA[2]. [1] R. Assman et al, LIAR, SLAC-PUB AP-103[2] The MAFIA Collaboration, MAFIA: L - The Linear Accelerator Tracking Code, CST GmbH, Darmstadt (1994)

MOPLT137	Beam Delivery Layout for the Next Linear Collider	luminosity, emittance, radiation, synchrotron	860
	A. Seryi, Y. Nosochkov, M. Woodley SLAC, Menlo Park, California
	We present the latest design and layout of the NLC Beam Delivery System (BDS) for the first and second interaction region (IR). This includes the beam switchyard, skew correction and emittance diagnostics section, collimation system integrated with the final focus, the primary and post linac tune-up beam dumps, and arcs of the second interaction region beamline. The layout and optics are optimized to deliver the design luminosity in the entire energy range from 90GeV to 1.3TeV CM, with the first IR BDS also having the capabilities for multi-TeV extension.

MOPLT151	Study of Arc-related RF Faults in the CEBAF Cryomodules	vacuum, ion, laser, electron	890
	E. Daly, D. Curry, J. Musson, G. Myneni, T. Powers, H. Wang, T.E. Whitlatch Jefferson Lab, Newport News, Virginia I.E. Campisi ORNL/SNS, Oak Ridge, Tennessee
	A series of measurements has been conducted on two superconducting radio-frequency cavity pairs, installed in cryomodules and routinely operated in the Continuous Electron Beam Accelerator Facility, in order to study the RF-vacuum interaction during an RF fault. These arc-related fault rates increase with increasing machine energy, contribute to system downtime and directly affect the accelerator?s availability. For this study, the fundamental power coupler waveguides have been instrumented with vacuum gauges, additional arc detectors, additional infrared sensors and temperature sensors in order to measure the system response during both steady-state operations and RF fault conditions. Residual gas analyzers have been installed on the waveguide vacuum manifolds to monitor the gas species present during cooldown, RF processing and operation. Simultaneous measurements of the signals are presented, a comparison with analysis is shown and results are discussed. The goal of this study is to characterize the RF-vacuum interaction during normal operations. With a better understanding of the installed system response, methods for reducing the fault rate may be devised, ultimately leading to improvements in availability.

MOPLT156	High Brightness Electron Guns for Next-Generation Light Sources and Accelerators	gun, electron, cathode, emittance	899
	H. Bluem, M.D. Cole, J. Rathke, T. Schultheiss, A.M.M. Todd AES, Princeton, New Jersey I. Ben-Zvi, T. Srinivasan-Rao BNL, Upton, Long Island, New York P. Colestock, D.C. Nguyen, R.L. Wood, L. Young LANL, Los Alamos, New Mexico D. Janssen FZR, Dresden J. Lewellen ANL, Argonne, Illinois G. Neil, H.L. Phillips, J.P. Preble Jefferson Lab, Newport News, Virginia
	Advanced Energy Systems continues to develop advanced electron gun and injector concepts. Several of these projects have been previously described, but the progress and status of each will be updated. The project closest to completion is an all superconducting RF (SRF) gun, being developed in collaboration with the Brookhaven National Laboratory, that uses the niobium of the cavity wall itself as the photocathode material. This gun has been fabricated and will shortly be tested with beam. The cavity string for a closely-coupled DC gun and SRF cavity injector that is expected to provide beam quality sufficient for proposed ERL light sources and FELs will be assembled at the Jefferson Laboratory later this year. We are also collaboration with Los Alamos on a prototype CW normal-conducting RF gun with similar performance, that will undergo thermal testing in late 2004. Another CW SRF gun project that uses a high quantum efficiency photocathode, similar to the FZ-Rossendorf approach, has just begun. Finally, we will present the RF design and cold test results for a fully axisymmetric, ultra-high-brightness x-band RF gun.

MOPLT170	eRHIC, Future Electron-ion Collider at BNL	electron, ion, luminosity, proton	923
	V. Ptitsyn, L. Ahrens, M. Bai, J. Beebe-Wang, I. Ben-Zvi, M. Blaskiewicz, J.M. Brennan, R. Calaga, X. Chang, E.D. Courant, A. Deshpande, A.V. Fedotov, W. Fischer, H. Hahn, J. Kewisch, V. Litvinenko, W.W. MacKay, C. Montag, S. Ozaki, B. Parker, S. Peggs, T. Roser, A. Ruggiero, B. Surrow, S. Tepikian, D. Trbojevic, V. Yakimenko, S.Y. Zhang BNL, Upton, Long Island, New York D.P. Barber DESY, Hamburg M. Farkhondeh, W. Franklin, W. Graves, R. Milner, C. Tschalaer, J. Van der Laan, D. Wang, F. Wang, A. Zolfaghari, T. Zwart MIT/BLAC, Middleton, Massachusetts A.V. Otboev, Y.M. Shatunov BINP SB RAS, Novosibirsk
	The paper reviews the progress made lately in the design of eRHIC, proposed future electron-ion collider on the basis of the existing RHIC machine. The eRHIC aims to provide collisions of electrons and positrons on ions and protons in center mass energy range of 25-70 GeV. The goal luminosities are in 10³²-10³³ 1/(scm²) values for e-p and in 10³⁰-10³¹ 1/(scm²) values for e-Au collisions. An essential design requirement is to provide longitudinally polarized beams of electrons and protons (and, possibly lighter ions) at the collision point. The eRHIC ZDR has been recently developed which considers various aspects of the accelerator design. An electron accelerator, which delivers about 0.5A polarized electron beam current in the electron energy range of 5 to 10 GeV, should be constructed at the BNL near existing ion rings of the RHIC collider and should intersect an ion ring at least in one of the available ion ring interaction regions. In order to reach the luminosity goals some upgrades in ion rings also would be required. Ways to reach lower beam emmittances (electron cooling) and higher beam intensities have to be realized.

TUXCH01	Review of ISOL-type Radioactive Beam Facilities	ion, target, heavy-ion, ion-source	45
	M. Lindroos CERN, Geneva
	The ISOL technique was invented in Copenhagen over 50 years ago and eventually migrated to CERN where a suitable proton drive beam was available at the Syncho-Cyclotron. The quick spread of the technique from CERN to many other laboratories has resulted in a large user community, which has assured the continued development of the method, physics in the front-line of fundamental research and the application of the method to many applied sciences. The technique is today established as one of the main techniques for on-line isotope production of high intensity and high quality beams. The thick targets used allows the production of unmatched high intensity radioactive beams. The fact that the ions are produced at rest makes it ideally suitable for low energy experiments and for post acceleration using well established accelerator techniques. The many different versions of the technique will be discussed and the many facilities spread all over the world will be reviewed. The major developments at the existing facilities and the challenges encountered will be presented. Finally, the possibility of using the resulting high intensity beams for the production of intense neutrino beams will be briefly discussed.
	Video of talk
	Transparencies

TUYLH02	Low and Medium Energy Beam Acceleration in High Intensity Linacs	rfq, quadrupole, lattice, beam-losses	108
	J. Stovall LANL, Los Alamos, New Mexico
	In the past two years accelerator builders have published papers describing mature designs of no fewer than 7 new high-performance proton linacs. These machines are typically designed to deliver multi-megawatt beams for applications in pure and applied research. All of these machines use the radio-frequency quadrupole (RFQ) linac for the first stage of acceleration to reach an energy of a few MeV. In essentially all cases, superconducting elliptical cavities have been adopted as the technology of choice for acceleration above ~100 MeV. Between the RFQ and the high-energy elliptical cavities, designers have proposed no fewer than 6 different types of accelerating structures. In many cases these structures are reaching maturity as a result of active development programs. In this paper, we review the design architectures of the ?low and medium energy? portions of these machines emphasizing recent experience and developments applicable to high-current linac designs.
	Video of talk
	Transparencies

TUPKF002	TRIUMF ISAC II RF Control System Design and Testing	controls, coupling, feedback, target	953
	M.P. Laverty, S.F. Fang, K. Fong TRIUMF, Vancouver
	The rf control system for the ISAC II superconducting cavities is a hybrid analogue/digital design which has undergone several iterations in the course of its development. In the current design, the cavity operates in a self-excited feedback loop, while phase locked loops are used to achieve frequency and phase stability. Digital signal processors are used to provide amplitude and phase regulation, as well as mechanical cavity tuning control. The most recent version also allows for the rapid implementation of operating firmware and software changes, which can be done remotely, if the need arises. This paper describes the RF control system and the experience gained in operating this system with a four-cavity test facility.

TUPKF004	First Results with a Fast Phase and Amplitude Modulator for High Power RF Application	proton, klystron, simulation, RF-structure	959
	D. Valuch, H. Frischholz, J. Tuckmantel CERN, Geneva C. Weil AFT, Backnang
	In a high energy and high power superconducting proton linac, it is more economical to drive several cavities with a single high power transmitter rather than to use one transmitter per cavity. This option has however the disadvantage of not permitting to individually control each cavity, which potentially leads to instabilities. Provided that it can be built at a reasonable cost, a fast phase & amplitude modulator inserted into each cavity feeder line can provide the necessary control capability. A prototype of such a device has been built, based on two fast and compact high power RF phase-shifters, magnetically biased by external coils. The design is described, together with the results obtained at high and low power levels.

TUPKF006	Custom Design of Medium Energy Linear Accelerator Systems	electron, ion, bunching, proton	965
	K. Dunkel, M. Pekeler, C. Piel, H.P. Vogel, P. vom Stein ACCEL, Bergisch Gladbach
	Based on customer requirements ACCEL Instruments is designing and building medium energy turn-key Linear Accelerator Systems for scientific applications. Within this paper design and performance of third generation synchrotron light source electron injector linacs will be presented. Further the design of a medium energy light ion linear accelerator will be discussed. This light ion accelerator is designed with independently phased superconducting rf cavities for cw operation and acceleration of different particle species and a variable Energy output.

TUPKF007	Series Fabrication Technologies for Normalconducting Linac and Storage Ring Cavities	vacuum, alignment, coupling, RF-structure	968
	P. vom Stein, K. Dunkel, B. Griep, C. Piel, H.P. Vogel ACCEL, Bergisch Gladbach
	Twelve HOM damped 476 MHz single cell cavities have been delivered for PEP II and the production of several 805 MHz CCL modules for SNS has recently been finalised by ACCEL Instruments. Based on those two examples, required key technologies for cavity production will be introduced. Final prove of successful manufacturing is given by low level rf measurements. Results of those measurements for above mentioned projects will be presented within this paper.

TUPKF008	Status of the HoBiCaT Superconducting Cavity Test Facility at BESSY	vacuum, superconductivity, radiation, power-supply	970
	J. Knobloch, W. Anders, J. Borninkhof, S. Jung, M. Martin, A. Neumann, D. Pflückhahn, M. Schuster BESSY GmbH, Berlin
	BESSY has recently constructed the HoBiCaT cryogenic test facility for superconducting TESLA cavity units, including all ancillary devices (helium tank, input coupler, tuner, magnetic shielding). It is designed to house two such units in a configuration similar to that envisaged for the superconducting CW linac of the BESSY FEL. These units are presently being fabricated, prepared and assembled by industry. HoBiCaT will be used to address many of the issues that must be considered prior to finalizing the design of the proposed linac. Rapid turn-around-tests permit the investigation of items such as RF regulation, microphonic detuning and cryogenic parameters/achievable pressure stability. These test will also serve as the first step towards qualifying the industrial production of assembled cavity units. The commissioning of HoBiCaT is scheduled for Spring 2004 and the current status is presented here.

TUPKF009	RF Control of the Superconducting Linac for the BESSY FEL	injection, simulation, klystron, beam-loading	973
	J. Knobloch, A. Neumann BESSY GmbH, Berlin
	In the BESSY-FEL superconducting linac, precise RF control of the cavities' voltage is imperative to maintain a bunch-to-bunch time jitter of less than 50 fs for synchronization in the HGHG section. The average beam loading is less than 1.5 kW/m and the cavity bandwidth is small so that high-gain RF feedback is required. Noise, in particular microphonic detuning, strongly impact the achievable level of control. Presented here are simulations of the cavity-feedback system, taking into account beam loading and noise sources such as measurement noise, microphonics and injection jitter. These simulations are used to estimate the resultant time and energy jitter of the bunches as they enter the HGHG section of the BESSY FEL.

TUPKF010	Cryogenic Considerations for CW Operation of TESLA-type Superconducting Cavity Modules for the BESSY FEL	simulation, cryogenics, extraction, radio-frequency	976
	J. Knobloch, W. Anders, X. Yu BESSY GmbH, Berlin
	The proposed BESSY FEL uses a CW superconducting driver linac to provide acceleration up to 2.3 GeV. Its design is based on well-established TESLA technology, originally intended for heat loads of order 1 W/m at 2.0 K. CW operation increases this load to levels of order 15 W/m at 1.8 K for a total heat load of 3 kW at 2.3 GeV (given conservative assumptions for the attainable Q-factor). Presented here is an analysis of the cryogenic layout, including two-phase-flow simulations of the 1.8-K helium which help identify the changes needed for reliable CW operation. A modified ‘‘CW'' module and helium distribution scheme is proposed.

TUPKF014	Electromagnetic Design of New RF Power Couplers for the S-DALINAC	electron, electromagnetic-fields, emittance, coupling	988
	M. Kunze, W.F.O. Müller, T. Weiland TEMF, Darmstadt M.B. Brunken, H.-D. Gräf, A. Richter TU Darmstadt, Darmstadt
	New rf power couplers for the Superconducting Darmstadt Linear Accelerator (S-DALINAC) injector have to be designed to transfer rf power up to 2 kW to the electron beam. This allows injector operation at beam currents from 0.15 mA to 0.2 mA and electron energies up to 14 MeV. The new couplers should possibly provide a variable external Q in the range from 5·10⁶ to 3·10⁹ and a small transverse kick. A variable coupling is needed to allow for perfect matching in the case of beam loading and when no beam is present, respectively. The second operation stage is used for cavity diagnostics. The asymmetric field distribution of the couplers generates emittance growth of the electron beam and therefore the transverse kick has to be minimized. Electromagnetic simulations are applied to investigate different coupler designs and to localize possible problems at an early stage. Cavity external Q and transverse kick can be calculated from 3D electromagnetic eigenmode solutions. The present coaxial-coaxial input couplers at the S-DALINAC are limited to power operation below 500 W under full reflection. Therefore, to reach power operation up to 2 kW two possible new realizations of low-kick waveguide couplers for the S-DALINAC injector are presented, namely a single-waveguide and a twin-waveguide coupler.

TUPKF015	Status of the Superconducting CH-Structure	proton, acceleration, ion, simulation	991
	H. Podlech, H. Deitinghoff, H. Klein, H. Liebermann, U. Ratzinger, A.C. Sauer, R. Tiede IAP, Frankfurt-am-Main
	H-mode cavities (IH-DTL, IH-RFQ, 4-Vane-RFQ) have been developed and operated successfully during the last decades for ion acceleration. At the IAP Frankfurt a new type of H-mode cavity, the CH-structure is under development. This multi cell drift tube cavity is operated in the TE21- mode. Due to its mechanical rigidity, room temperature as well as superconducting versions can be realized. Superconducting CH-structures might be used especially for cw operated linacs in nuclear research facilites and applied research projects like XADS or IFMIF. A superconducting 352 MHz CH-structure (beta=0.1) with 19 gaps will be available for first tests in 2004. We present the status of the cavity and of the new cryo laboratory in Frankfurt.

TUPKF016	Dynamic Lorentz Force Detuning Studies in TESLA Cavities	resonance, coupling, beam-loading, acceleration	994
	V. Ayvazyan, S. Simrock DESY, Hamburg
	Dynamic detuning of the superconducting rf cavities due to Lorentz force induced mechanical excitation is a critical concern since the magnitude can approach the cavity bandwidth and require significant additional rf power for field control. In this paper, the influence of high accelerating fields on the resonance frequency in superconducting TESLA cavities is discussed. Cavities at the TESLA Test Facility have been operated at the design operating gradient close to 25 MV/m. It is shown that Lorentz force detuning constant factors are different for different cavities, significant spread have been observed.

TUPKF017	Electrons Beam Dynamics of the 100 MeV Preinjector Helios for the SOLEIL Synchrotron	gun, emittance, electron, focusing	997
	A.S. Setty THALES, Colombes
	A 100 MeV electron linac is under construction, in order to inject into the booster synchrotron of SOLEIL. The linac is designed to work according to two operation modes : a short pulse mode (2 ns - 0,5 nC) and a long pulse mode (300 ns - 8 nC). Calculation of the beam dynamics, using our selfmade code PRODYN, has been carried out from the gun to the end of the linac. Special care has been taken on the gun design to avoid an overfocusing outcoming beam in order to obtain a final low emittance. Calculations results are given.

TUPKF019	Recent Developments on Superconducting b035 and b015 Spoke Cavities at IPN for Low and Medium Energy Sections of Proton Linear Accelerators.	proton, pick-up, tandem-accelerator, vacuum	1003
	G. Olry, J.-L. Biarrotte, S. Blivet, S. Bousson, F. Chatelet, D. Gardès, N. Hammoudi, T. Junquera, J. Lesrel, C. Miélot, A.C. Müller, D. Ruffier, H. Saugnac, P. Szott, J.P. Thermeau IPN, Orsay
	Spoke cavities studies leaded by IPN-Orsay, for both XADS and EURISOL projects, are fully integrated within the 5th and 6th European Framework Programs. During 2003, several tests have been performed on the first b035 spoke cavity prototype. They have demonstrated the great potential of this type of cavity in term of RF performances (Eacc max=12.5 MV/m at T=4.2 K) and mechanical behavior (very low sensitivity to errors fabrication, good stiffness…). Following the upgrade of our cryogenic facility, we have tested, this spring, the cavity at 2 K. These new results will be presented in this paper. In parallel, the fabrication of a new spoke cavity (2-gap, 352 MHz, b015) has begun in January. While keeping the same geometry than that of the b035 cavity, we carried out significant changes on the coupler port and stiffening system designs. We report here in particular, RF calculations concerning the new location of the coupler port (in order to minimize losses due to magnetic field) and also, mechanical calculations about the new stiffening ring. Finally, we will present the preliminary thought on modular cryomodule which are based on the ?short? cryomodule concept used with the Quarter Wave Resonators for the SPIRAL-2 project.

TUPKF022	Constructionand Testing of the Beta=0.31, 352 MHz Superconducting Half-wave Resonator for the SPES Project	vacuum, quadrupole, coupling, proton	1012
	A. Facco, W. Lu, F. Scarpa INFN/LNL, Legnaro, Padova E. Chiaveri, R. Losito CERN, Geneva V. Zviagintsev TRIUMF, Vancouver
	The interest in low- and medium- beta superconducting cavities is presently focused to future high intensity proton, deuteron and heavy ion linacs. A particular application is acceleration of cw and pulsed beams of variable q/A, which requires cavities with a small number of gaps and excellent mechanical stability. We have designed and constructed a 2 gap, 352 MHz SC half wave cavity aiming to similar characteristics and fitting the requirements of the intermediate-beta section of the LNL-SPES driver. The status of the project and the first test results will be presented.

TUPKF023	Construction of a 161 MHz, beta=0.16 Superconducting QWR with Steering Correction for RIA	vacuum, ion, superconductivity, light-ion	1015
	A. Facco, W. Lu, F. Scarpa INFN/LNL, Legnaro, Padova E. Chiaveri, R. Losito CERN, Geneva T.L. Grimm, W. Hartung, F. Marti, R.C. York NSCL, East Lansing, Michigan V. Zviagintsev TRIUMF, Vancouver
	We have built a 161 MHz, b=0.16 superconducting Quarter Wave Resonator with steering correction for the low beta section of RIA. This bulk niobium, double wall cavity, compatible with both separate vacuum between beam line and cryostats or unified one, was designed in collaboration between MSU-NSCL and LNL. The design is suitable for extension to other frequencies, e.g. to obtain the 80 MHz, beta=0.085 cavity required in RIA. The shaped drift tube allows correction of the residual QWR steering that can cause emittance growth especially in light ions; this could make this resonator a good alternative to Half-Wave resonators in high intensity proton-deuteron linacs, like the SPES injector project at LNL. First test results will be presented.

TUPKF026	RF Tests of the Beta=0.5 Five Cell TRASCO Cavities	electron, pick-up, vacuum, superconductivity	1024
	A. Bosotti, C. Pagani, P. Pierini INFN/LASA, Segrate (MI) J.P. Charrier, B. Visentin CEA/DSM/DAPNIA, Gif-sur-Yvette G. Ciovati, P. Kneisel Jefferson Lab, Newport News, Virginia
	Two complete 5 cell superconducting cavities at b=0.5 have been designed and fabricated. The cavities have been designed to minimize peak electric and magnetic fields, with a goal of 8.5 MV/m of accelerating gradient, at a Q > 5E9. The cavities are currently in the testing stage and the results of the vertical tests will be presented at this conference.

TUPKF033	Cryogenic Performance of the Prototype Cryomodule for ADS Superconducting LINAC	alignment, synchrotron, proton, radiation	1033
	N. Ohuchi, E. Kako, S. Noguchi, T. Shishido, K. Tsuchiya KEK, Ibaraki N. Akaoka, H. Kobayashi, N. Ouchi, T. Ueno JAERI/LINAC, Ibaraki-ken T. Fukano Nippon Sanso Corporation, Tokyo H. Hara, M. Matsuoka, K. Sennyu MHI, Kobe
	A prottype cryomodule containing two 9-cell superconducting cavities of b=0.725 and f=972MHz is being constructed under the collaboration of Japan Atomic Energy Research Institute (JAERI) and High Energy Accelerator Research Organization (KEK) on the development of superconducting LINAC for Accelerator Driven System (ADS). Cryogenic performances of the cryomodule and 2K He-system will be reported.

TUPKF036	RF Property of the Prototype Cryomodule for ADS Superconducting Linac	vacuum, coupling, simulation, proton	1042
	E. Kako, S. Noguchi, N. Ohuchi, T. Shishido KEK, Ibaraki N. Akaoka, H. Kobayashi, N. Ouchi, T. Ueno JAERI/LINAC, Ibaraki-ken H. Hara, M. Matsuoka, K. Sennyu MHI, Kobe
	A prototype cryomodule containing two 9-cell superconducting cavities of beta=0.725 and frequency=972MHz is being constructed under the collaboration of Japan Atomic Energy Research Institute (JAERI) and High Energy Accelerator Research Organization (KEK) on the development of superconducting LINAC for Accelerator Driven System (ADS). Design and performance of RF components will be reported.

TUPKF058	Test Results for the New 201.25 MHz Tetrode Power Amplifier at LANSCE	proton, power-supply, electron, impedance	1078
	J.T.M. Lyles, S. Archuletta, J. Davis, L. Lopez, G. Roybal LANL/LANSCE, Los Alamos, New Mexico
	A new RF amplifier has been constructed for use as the intermediate power amplifier stage for the 201.25 MHz Alvarez DTL at LANSCE. It is part of a larger upgrade to replace the entire RF plant with a new generation of components. The new RF power system under development will enable increased peak power with higher duty factor. The first tank requires up to 400 kW of RF power. This can be satisfied using the TH781 tetrode in a THALES cavity amplifier. The same stage will be also used to drive a TH628 Diacrode? final power amplifier for each of the three remaining DTL tanks. In this application, it will only be required to deliver approximately 150 kW of peak power. Details of the system design, layout for DTL 1, and test results will be presented.

TUPKF059	Simulation of Dark Currents in X-band Accelerator Structures	simulation, electron, vacuum, emittance	1081
	K.L.F. Bane, V.A. Dolgashev, G.V. Stupakov SLAC, Menlo Park, California
	In high gradient accelerator structures, such as those used in the main linac of the GLC/NLC, electrons are emitted spontaneously from the structure walls and then move under the influence of the rf fields. In this report we study the behavior of this "dark current" in X-band accelerator structures using a simple particle tracking program and also the particle-in-cell program MAGIC. We address questions such as what is the sensitivity to emission parameters, what fraction of dark current is trapped and reaches to the end of a structure, and what are the temporal, spatial, and spectral distributions of dark current as functions of accelerating gradient.

TUPKF067	High Power Magnicons at Decimeter Wavelength for Muon and Electron-Positron Colliders	collider, gun, electron, acceleration	1099
	O.A. Nezhevenko, V.P. Yakovlev Omega-P, Inc., New Haven, Connecticut J.L. Hirshfield Yale University, Physics Department, New Haven, CT
	The CLIC drive linac requires pulsed RF amplifiers with a power of 50 MW at 937 MHz. In turn the muon collider requires 100 MW, 800 MHz RF amplifiers for the final stages of acceleration. In this paper conceptual designs of magnicons for these applications are presented. In addition to the typical magnicon advantages in power and efficiency, the designs offers substantially shorter tube length compared to either single^- or multiple-beam klystrons.

TUPKF068	JLAB Hurricane Recovery	vacuum, site, cryogenics, superconductivity	1102
	A. Hutton, D. Arenius, F.J. Benesch, S. Chattopadhyay, E. Daly, V. Ganni, O. Garza, R. Kazimi, R. Lauze, L. Merminga, W. Merz, R. Nelson, W. Oren, M. Poelker, T. Powers, J.P. Preble, C. Reece, R.A. Rimmer, M. Spata, S. Suhring Jefferson Lab, Newport News, Virginia
	Hurricane Isabel, originally a Category 5 storm, arrived at Jefferson Lab on September 18 with winds of only 75 mph creating little direct damage to the infrastructure. However, electric power was lost for four days allowing the superconducting cryomodules to warm up and causing a total loss of the liquid helium. The subsequent recovery of the cryomodules and the impact of the considerable amount of opportunistic preventive maintenance provides important lessons for all accelerators complexes, not only those with superconducting elements. The details of how the recovery process was structured and the resulting improvement in accelerator availability will be discussed in detail.

TUPKF072	Production and Performance of the CEBAF Upgrade Cryomodule Intermediate Prototypes	damping, vacuum, controls, synchrotron	1105
	A-M. Valente, E. Daly, J.R. Delayen, M. Drury, R. Hicks, C. Hovater, J. Mammosser, H.L. Phillips, T. Powers, J.P. Preble, C. Reece, R.A. Rimmer, H. Wang Jefferson Lab, Newport News, Virginia C. Thomas-Madec SOLEIL, Gif-sur-Yvette
	We have installed two new cryomodules, one in the nuclear physics accelerator (CEBAF) and the other in the Free Electron Laser (FEL) of Jefferson Lab. The new cryomodules consist of 7-cell cavities with the original CEBAF cell shape and were designed to deliver gradients of 70 MV/module. Several significant design innovations were demonstrated in these cryomodules. This paper describes the production procedures, the performance characteristics of these cavities in vertical tests, results of tests in the new cryomodule test facility (CMTF) as well as the commissioning in the CEBAF tunnel and FEL. Performances and limitations after installation in the accelerators are discussed in this paper along with improvements proposed for future cryomodules.

TUPKF078	High Current Superconducting Cavities at RHIC	impedance, simulation, electron, dipole	1120
	R. Calaga, I. Ben-Zvi, Y. Zhao BNL, Upton, Long Island, New York J. Sekutowicz Jefferson Lab, Newport News, Virginia
	A five-cell high current superconducting cavity for the electron cooling project at RHIC is under fabrication. Higher order modes (HOMs), one of main limiting factors for high current energy-recovery operation, are under investigation. Calculations of HOMs using time-domain methods in Mafia will be discussed and compared to calculations in the frequecy domain. A possible motivation towards a 2x2 superstructure using the current five-cell design will be discussed and results from Mafia will be presented. Beam breakup thresholds determined from numerical codes for the five-cell cavity as well as the superstructure will also be presented.

TUPLT001	Beam Dynamics in 100 MeV S-Band Linac for CANDLE	emittance, bunching, electron, gun	1129
	B. Grigoryan, V.M. Tsakanov CANDLE, Yerevan
	The report presents the results of the beam dynamics study in 100 MeV S-band linear accelerator foreseen as an injector for the CANDLE light source. An impact of the excited longitudinal and transverse wake fields on the particle energy spread and the beam transverse emittance are given.

TUPLT007	The CERN-SPL Chopper Concept and Final Layout	vacuum, quadrupole, proton, antiproton	1141
	F. Caspers, Y. Cuvet, J. Genest, M. Haase, M. Paoluzzi, A. Teixeira CERN, Geneva
	The fast chopper for the CERN SPL (Superconducting Proton Linac) consists of a double meander structure with a beta (v/c) value of 8 % printed on an alumina substrate for the deflecting plates. Each chopper unit is 50 cm long and housed in a quadrupole magnet surrounding the vacuum chamber. The deflecting plates are operated simultaneously in a dual mode, namely traveling wave mode for frequencies above about 10 MHz and as quasi electro-static deflectors below. The deflecting structures are water-cooled to handle heating from beam losses as well as from the deflecting signal. A detailed mechanical layout is presented including the tri-axial feeding and termination technique as well as a discussion of the drive amplifier

TUPLT011	The LHC Lead Ion Injector Chain	ion, electron, injection, vacuum	1153
	K. Schindl, A. Beuret, A. Blas, J. Borburgh, H. Burkhardt, C. Carli, M. Chanel, T. Fowler, M. Gourber-Pace, S. Hancock, C.E. Hill, M. Hourican, J.M. Jowett, K. Kahle, D. Kuchler, A.M. Lombardi, E. Mahner, D. Manglunki, M. Martini, S. Maury, F. Pedersen, U. Raich, C. Rossi, J.-P. Royer, R. Scrivens, L. Sermeus, E.N. Shaposhnikova, G. Tranquille, M. Vretenar, T. Zickler CERN, Geneva
	A sizeable part of the LHC physics programme foresees heavy ion (lead-lead) collisions with a design luminosity of 10²⁷ cm-2 s-1. This will be achieved after an upgrade of the ion injector chain comprising Linac3, LEIR, PS and SPS machines. Each LHC ring will be filled in ~10 minutes with ~600 bunches, each of 7 10⁷ Pb ions. Central to the scheme is the Low Energy Ion Ring (LEIR), which transforms long pulses from Linac3 to high-brilliance bunches by means of 6D multi-turn injection and accumulation via electron cooling. Major limitations along the chain, including space charge, intra-beam scattering, vacuum issues, and emittance preservation are highlighted. The conversion from LEAR (Low Energy Antiproton Ring) to LEIR includes new magnets and power converters, high-current electron cooling, broad-band RF cavities, upgraded beam diagnostics, and UHV vacuum equipment relying on beam scrubbing to achieve a few 10-12 mbar. Major hardware changes in Linac3 (Electron Cyclotron Resonance source, repetition rate, energy ramping cavity), PS (new injection hardware, elaborate RF gymnastics, stripping insertion), and SPS (100 MHz system) are described. An early beam scenario, using fewer bunches but the same bunch intensity to deliver a lower luminosity, reduces the work required for LHC ion operation in spring 2008.

TUPLT014	Comparative Design Studies of a Super Buncher for the 72 MeV Injection Line of the PSI Main Cyclotron	cyclotron, impedance, simulation, injection	1162
	J.-Y. Raguin, A. Adelmann, M. Bopp, H. Fitze, M. Pedrozzi, P. Schmelzbach, P. Sigg PSI, Villigen
	The envisaged current upgrade from 2 to 3 mA of the PSI 590-MeV main cyclotron requires an increase of the global accelerating voltage of the 50-MHz cavities which leads to a nearly unacceptable RF requirement for the 150-MHz flattop cavity. In order to preserve the longitudinal acceptance and transmission of the machine while relaxing the high demands on the flattop system, it is conceivable to install a buncher in the 72-MeV injection line. To this end, normal-conducting 150-MHz half-wave resonators and 500-MHz two-gap drift-tube cavities have been designed and optimised for minimum input power and peak surface fields. The dependence of the RF properties (Q0, shunt impedances and peak fields) with beam apertures and gap voltages compatible with beam-dynamics requirements are presented.

TUPLT027	Status of the HITRAP Decelerator Linac at GSI	rfq, ion, injection, heavy-ion	1201
	C.A. Kitegi, A. Bechtold, U. Ratzinger, A. Schempp IAP, Frankfurt-am-Main T. Beier, L. Dahl, C. Kozhuharov, W. Quint, M. Steck GSI, Darmstadt S. Minaev ITEP, Moscow
	Within the European Network HITRAP (heavy Ion trap) trapped and cooled higly charged ions up to U⁹²⁺ will become avilable for a variety of attractive experiments in atomic physics. Heavy ions are produced, accelerated and stripped in the GSI accelerator complex and are stored in the ESR down to 4 MeV/u. To be captured in HITRAP, ions have to be decelerated to energies below 6 keV/u. The decelerator proposed to achieve these energies is a combination of an IH Drift tube cavity operating in the H11(0) mode and a RFQ. The operating frequency is 108.408MHz . The A/q range of the linac is up to 3. A very efficient deceleration by up to 11 MV along the 2.7 m long IH cavity with a rf power of 200kw is achieved by applying the KONUS beam dynamics. The deceleration from 500 A.keV down 6A.keV is provided by a 1.8 m long 4-rod RFQ.The beam dynamics as well as the cavity design of that linac will be described.The decelerator linac will be installed in the reinjection beam line and is being developed in collaboration between GSI and the Frankfurt University .

TUPLT029	Status of the Superconducting D⁺-CH-DTL Design for IFMIF	rfq, quadrupole, simulation, space-charge	1207
	A.C. Sauer, H. Deitinghoff, H. Klein, H. Liebermann, O. Meusel, H. Podlech, U. Ratzinger, R. Tiede IAP, Frankfurt-am-Main
	Within the IFMIF project (International Fusion Materials Irradiation Facility) a high current D⁺-linac operated in cw mode has to be developed. The acceleration of a 125 mA D⁺-beam from 0.1 MeV up to 40 MeV must be performed at an extremely low loss rate (0.1-0.2 microA/m). One optional layout of the acceleration facility consists of a high current ion source, low energy beam transport (LEBT), Radio-Frequency-Quadrupol (RFQ) followed by a superconducting H-type DTL. The matching of the beam between subsequent linac sections has to be carefully optimized to avoid an activation of the structures. Actual beam dynamics simulations for such a linac design including parameter errors of components are reported. Consequences for the LEBT- and RFQ-section are discussed.

TUPLT032	The Frankfurt Funneling Experiment	rfq, ion, ion-source, emittance	1213
	H. Zimmermann, U. Bartz, N. Mueller, A. Schempp, J. Thibus IAP, Frankfurt-am-Main
	The Frankfurt Funneling Experiment is a scaled model of the first funneling stage of a HIF driver to gather experiences in the funneling technique. It is a procedure to multiply beam currents at low energies in several stages. In each stage two beam lines are combined to a common beam line. The funneling technique is required for new proposed high current accelerator facilities like HIDIF. The main goal is to prevent emittance growth during the funneling process. Our experiment consists of two ion sources, a Two-Beam RFQ accelerator, two different funneling deflectors and a beam diagnostic equipment system. We have demonstrated the principle of funneling with both deflector types. But the measurements have shown a bad matching of the RFQ to the funneling deflector. Now with our new RFQ electrode design we achieve a special three dimensional matching to the deflector. The new results of our measurements and simulations will be presented.

TUPLT044	Delta-T Procedure for Superconducting Linear Accelerator	pick-up, simulation, injection, acceleration	1249
	A. Bogdanov, R. Maier, Y. Senichev FZJ/IKP, Jülich
	Development of the tune-up procedure for a linear accelerator is the next important stage after the design is complete. Conventional delta-T procedure developed for tuning of a normal-conducting linear accelerator by Crandall allows setting up of accelerating field amplitude and phase in cavity with known phase velocity. However, application of the delta-T procedure to a superconducting linac meets some difficulties. In particular, the synchronous phase velocity in superconducting linac is determined by RF phase shift between cavities, but not by geometrical size of accelerating cells as in normal conducting linac. Additionally, in superconducting linac the smaller phase advance leads to an insensibility of particles at the cavity exit to the variation of the electric field inside the cavity. In the paper we consider the modified delta-T procedure adjusted for superconducting linac. Numerical simulations prove that by proposed technique both tasks of preservation of necessary stable region motion and providing the beam with required final energy can be successfully solved.

TUPLT045	Separatrix Formalism Applied to Linacs Accelerating Particles with Different Charge to Mass Ratio	acceleration, space-charge, proton, simulation	1252
	A. Bogdanov, R. Maier, Y. Senichev FZJ/IKP, Jülich
	We have developed separatrix formalism for superconducting linear accelerators. This method allows optimizing the quasi-synchronous velocity behavior along a linac. It gives a great advantage in acceleration of particles with different charge to mass ratio. In the article design optimization of structure supposed to accelerate different particles is presented. As an example for numerical simulation superconducting injector COSY is taken.

TUPLT047	First Results of Pulsed Superconducting Half-wave Resonators	vacuum, synchrotron, resonance, coupling	1258
	R. Stassen, R. Eichhorn, F.M. Esser, B. Laatsch, R. Maier, G. Schug, R. Tölle FZJ/IKP, Jülich
	A pulsed linac for the cooler synchrotron COSY was projected based on superconductive half-wave resonators (HWRs). The concept of single phased resonators is a great challenge related to the requirement of accelerating protons and deuterons up to a similar energy. A cryomodule, which houses four cavities was designed in Cooperation with FZJ-ZAT, taking into account the restricted space and the special requirements of a linear accelerator. Two prototypes of the 160MHz Half-Wave Resonators (HWRs) were built at different companies. The fabrication differs slightly concerning the top and bottom parts of the cavity as well as the welding of the inner and outer conductor. First results of warm and cold measurements will be presented. The behaviour of the adjustable 4kW main coupler as well as the mechanical tuner can be tested together with the HWR in a new vertical test-cryostat.

TUPLT053	Recent Evolutions in the Design of the French High Intensity Proton Injector (IPHI)	rfq, diagnostics, proton, vacuum	1273
	P.-Y. Beauvais CEA/DSM/DAPNIA, Gif-sur-Yvette
	In 1997, the two French National Research Agencies (CEA and CNRS) decided to collaborate in order to study and construct a prototype of the low energy part of a High Power Proton Accelerator (HPPA). The main objective of this project (the IPHI project), is to allow the French team to master the complex technologies used and the control concepts of the HPPAs. Recently, a collaboration agreement was signed with the CERN and led to some evolutions in the design and in the schedule. The IPHI design current was maintained at 100 mA in Continuous Wave mode. This choice should allow to produce a high reliability beam at reduced intensity (typically 30 mA) tending to fulfill the Accelerator Driven System requirements. The output energy of the Radio Frequency Quadrupole (RFQ), originally set to 5 MeV, was reduced to 3 MeV, allowing then the adjunction and the test in pulsed mode of a chopper line developed by the CERN for the Superconducting Proton Linac (SPL). In a final step, the IPHI RFQ and the chopper line should become parts of the SPL injector. In this paper, the IPHI project evolutions are reported as well as the construction and operation schedule.

TUPLT057	Beam Dynamics Studies for the Fault Tolerance Assessment of the PDS-XADS Linac Design	quadrupole, beam-losses, target, simulation	1282
	J.-L. Biarrotte IPN, Orsay M. Novati, P. Pierini INFN/LASA, Segrate (MI) H. Safa, D. Uriot CEA/DSM/DAPNIA, Gif-sur-Yvette
	In order to meet the high availability/reliability required by the PDS-XADS design the accelerator needs to implement, to the maximum possible extent, a fault tolerance strategy that would allow beam operation in the presence of most of the envisaged faults that could occur in its beamline components. In this work we report the results of beam dynamics simulations performed to characterize the effects of the faults of the main linac components (cavities, deflecting and focusing magnets, …) on the beam parameters. The outcome of this activity is the definition of the possible corrective and preventive actions that could be conceived (and implemented in the system) in order to guarantee the fault tolerance characteristics of the accelerator.

TUPLT058	High Intensity Linac Driver for the SPIRAL-2 Project : Design of Superconducting 88 MHz Quarter Wave Resonators (beta 0.12), Power Couplers and Cryomodules	ion, heavy-ion, quadrupole, resonance	1285
	T. Junquera, J.-L. Biarrotte, S. Blivet, S. Bousson, C. Commeaux, G. Olry, H. Saugnac IPN, Orsay P. Balleyguier CEA/DAM, Bruyères-le-Châtel M. Fruneau, Y. Gomez-Martinez, E. Vernay, F. Vezzu LPSC, Grenoble
	A Superconducting Linac Driver, delivering deuterons with energy up to 40 MeV (5 mA) and heavy ions with energy of 14.5 MeV/u (1 mA ), is proposed for the Spiral-2 radioactive beams facility. For the high energy section of the linac, a superconducting 88 MHz Quarter Wave Resonator (beta 0.12) has been designed and the optimisation of RF and mechanical performances will be presented. Based on the present state-of-art of the Superconducting RF technology, maximum electric surface field of 40 MV/m and magnetic surface field of 80 mT, have been adopted which should allow to reach an accelerating field of 7 MV/m (energy gain 3 MeV per resonator). A first complete prototype is under construction. The high intensity deuteron beam specifications have imposed the design of an original power coupler (maximum power 20 KW). The RF, mechanical, and thermal characteristics will be presented. The design of the cryomodule for this high energy section, integrating two QWR with its associated equipments (couplers, tuners, helium tanks), will be presented.

TUPLT070	Study of a Linac Booster for Proton Therapy in the 30-62 MeV Energy Range	proton, cyclotron, booster, impedance	1312
	V.G. Vaccaro, A. D'Elia, M.R. Masullo Naples University Federico II and INFN, Napoli D. Capasso, S. Lanzone Naples University Federico II, Napoli T. Clauser, A. Rainò INFN-Bari, Bari C. De Martinis, D. Giove, M. Mauri INFN/LASA, Segrate (MI) V. Variale Bari University, Science Faculty, Bari
	Recent results in accelerator physics have shown the feasibility of a coupling scheme between a cyclotron and a linac for proton acceleration. Cyclotrons with energies up to 30 MeV, mainly devoted to radioisotopes production, are available in a large number of medical centres. These two evidences have suggested the idea to study and design a linac booster able to increase the initial proton energy up to the values required for the treatment of tumors, like the ocular ones. The main challenge in such a project is related to meet the requirements arising from the beam dynamics with the constrains due both to the mechanical structures and tolerances and to the heat dissipation mechanism chosen in the design. In this paper we will review the rationale of the project and we will discuss the basic design of a compact 3 Ghz linac with a new approach to the cavities used in a SCL (Side Coupled Linac) structure

TUPLT071	A 5 MeV Electron Linac for Radiation Processing	electron, radiation, cathode, focusing	1315
	A. Trifirò, L. Auditore, R.C. Barnà, D. De Pasquale, A. Italiano, M. Trimarchi INFN - Gruppo Messina, S. Agata, Messina
	In recent years, radiation processing is rapidly growing in various field of industrial treatments and scientific research as a safe, reliable and economic technique. To match the requirements of several applications, a 5 MeV, 1 kW electron linac has been developed at the Dipartimento di Fisica (Università di Messina), in collaboration with the ENEA Accelerators Group (Frascati- Rome). This self- containing standing wave accelerator, driven by a 3 GHz, 2.5 MW Magnetron, has been designed, by means of the SUPERFISH and PARMELA codes, in such a way as to obtain an autofocusing structure, that will be used to develop a transportable system for 'in-situ' industrial radiography and X-ray digital tomography. For this accelerator, compact pulse forming circuits have been properly developed for the magnetron and the cathode, and pulse frequency can be varied ranging from 1 to 300 Hz, thus allowing the study of several applications of radiation processing. Main features of the accelerating structure, as well as beam spot dimensions, surface dose distribution and electron beam energy range will be described.

TUPLT074	Dark Current Reduction System for SPring-8 Linac	single-bunch, storage-ring, gun, synchrotron	1324
	T. Kobayashi, T. Asaka, H. Hanaki, M. Shoji, S. Suzuki, K. Tamura JASRI/SPring-8, Hyogo
	The SPring-8 linac accelerates dark currents generated by its injector part up to 1 GeV. These dark currents are injected with main beam into the SPring-8 storage ring and then spoil the purity of the stored beam. The dark currents are mainly composed of a grid emission current from a thermionic gun and field emission currents from rf accelerating structures. A beam deflector for kicking only the grid emission by a pulsed electric field was developed and installed in the SPring-8 linac. We observed that the beam deflector greatly reduced the grid emission current accelerated up to 1 GeV. The measured purity of the stored single-bunched beam was about 5x10-6 when the deflector operated, which was almost 1/100 of the purity without filtering by the deflector. However, the deflector, which is installed before the prebucher, cannot reduced the field emission currents from the buncher cavities and the first acccelerating structure. These dark currents take considerable proportion of the total dark currents observed at the end of the linac. We are trying to spin off the field emission currents by weak magnetic fields across the accelerating structure generated by several coils.

TUPLT075	Improvements of SPring-8 Linac towards Top-up Operation	injection, synchrotron, vacuum, power-supply	1327
	S. Suzuki, T. Asaka, H. Dewa, H. Hanaki, T. Kobayashi, T. Masuda, A. Mizuno, T. Taniuchi, H. Tomizawa, K. Yanagida JASRI/SPring-8, Hyogo
	The top-up operation of the SPring-8 storage ring will start in May, 2004. In order to realize alternative injection into the booster synchrotron in the top-up operation and the NewSUBARU, an AC bending magnet replaced the DC bending magnet in the beam transport line to the booster synchrotron. This magnet operates at 1 Hz with a trapezoid current pattern. The 1-GeV electron beam goes at the bottom of the current pattern to the NewSUBARU or at the top of the pattern to the booster synchrotron. In order to obtain the higher reliability of the linac for the top-up operation, reinforcement of the beam monitor systems, further improvement of RF phase stability and upgrade of the control system were required. BPM?s has been newly installed in energy dispersion sections, and beam transport feedback control is in development. The phase variation in the RF system was reduced by the regulation of the gas pressure in the waveguide of the klystrons drive system. We re-engineered the VME systems to maximize availability of the linac operation considering its reliability, usability, expandability and flexibility.

TUPLT080	Design of the Beam Transportation Line from the Linac to the 3-GeV RCS for J-PARC	injection, simulation, emittance, quadrupole	1342
	T. Ohkawa JAERI, Ibaraki-ken M. Ikegami KEK, Ibaraki
	L3BT is beam transportation line from the linac to the 3-GeV RCS which is the part of the accelerators for the High-Intensity Proton Accelerator Facility Project, J-PARC. For the requirement of the beam loss minimization, the L3BT does not only connect the linac to the 3GeV RCS, but also modifies the linac beam to the acceptable shape for the 3-GeV RCS. The required beam parameters at the injection point of the RCS are momentum spread < ±0.1% (100%)and transverse emittance < 4pmm.mrad (99%). To achieve these beam qualities, the L3BT should have following functions: momentum compaction, halo scraping and beam diagnostics. In this paper, results of the design and beam simulation of the L3BT are presented.

TUPLT082	Generation of a Femtosecond Electron Beam for Nanoscience and Nanotechnology	electron, gun, laser, emittance	1348
	J. Yang, T. Kozawa, S. Tagawa, Y. Yoshida ISIR, Osaka
	A new S-band femtosecond electron linear accelerator was developed in Osaka University for the study of radiation-induced ultrafast physical and chemical reactions in femtosecond time regions. The femtosecond electron accelerator was constructed with a laser driven photocathode RF gun, a linear accelerator (linac) and a magnetic pulse compressor. The RF gun was driven by a mode-locked Nd:YLF picosecond laser. The electron beam produced by the RF gun was accelerated in the linac with energy modulattion by adjusted the RF phase. The magnetic pulse compression, which was constructed with two 45o-bending magnets and four quadrupole magnets, is a technique to longitudinally focus a charged beam by rotating the phase space distribution in a magnetic field. The picosecond electron pulse, which was generated in the RF gun and accelerated in the linac with energy modulation, was compressed into femtosecond by adjusted the quadrupole magnetic fields. The femtosecond electron pulse is expected for the studies of ultrafast reactions in nano-space.

TUPLT085	J-PARC Construction and its Linac Commissioning	proton, synchrotron, quadrupole, site	1351
	Y. Yamazaki JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
	The J-PARC(Japan Proton Accelerator Research Complex) accelerator is under construction in JAERI Tokai site. The beam commissioning will be started there by the end of 2006. Prior to this, the front end of the linac was beam-commissioned in 2003 at KEK. The negative hydrogen beam with a peak current of 30 mA was accelerated up to 20 MeV by the first tank of three DTL's following the 3-MeV RFQ linac. The 324-MHz DTL contains the electro quadrupole magnets with water-cooling channels specially fabricated by means of electroforming and wire-cutting technologies. The construction status of the J-PARC accelerator is also presented.

TUPLT086	A 40MeV Electron Source with a Photocathode for X-ray Generation through Laser-compton Scattering	electron, laser, emittance, gun	1354
	F. Sakai, N. Nakajyo, Y. Okada, T. Yanagida, M. Yorozu SHI, Tokyo
	.3 keV femtosecond X-ray generation through laser-Compton scattering with 14MeV electron source and a TW Ti:sapphire laser was achieved. In order to increase the X-ray energy up to 15 keV for some applications, e.g. protein crystallography, we modified the system to increase electron energy. Electron beams emitted from a S-band RF photocathode are accelerated up to 40MeV with two 1.5m standing-wave linacs. The beams are bended at 90 degree using an achromatic bending system, then focused with a triplet quadrupole-magnet to be interacted with laser pulses. The characteristics of electron beams, emittance, energy and energy dispersion, will be described.

TUPLT096	RFQ Low Level RF System for the PEFP 100MeV Proton Linac	rfq, feedback, proton, simulation	1381
	I.H. Yu, M.-H. Chun, K.M. Ha, Y.J. Han, W.H. Hwang, M.H. Jeong, H.-S. Kang, D.T. Kim, S.-C. Kim, I.-S. Park, J.S. Yang PAL, Pohang Y.-S. Cho, K.T. Seol KAERI, Daejon
	The 100MeV Proton linear accelerator (Linac) for the PEFP (Proton Engineering Frontier Project) will include a 3MeV, 350MHz RFQ(Radio-Frequency Quadrupole) Linac. The RFQ accelerates a 20mA proton beam from 50keV to 3MeV. The low level RF system for RFQ provides field control. In addition to field control, it provides cavity resonance control. An accelerator electric field stability of ± 1% in amplitude and ± 1° in phase is required for the RF system. The low level RF system has been designed and is now being fabricated.

TUPLT111	RF Focusing of Low-Charge-to-Mass-Ratio Heavy-Ions in a Superconducting Linac	focusing, ion, emittance, superconducting-RF	1405
	E.S. Masunov, D.A. Efimov MEPhI, Moscow P.N. Ostroumov ANL/Phys, Argonne, Illinois
	A post-accelerator of radioactive ions (RIB linac) must produce high-quality beams over the full mass range, including uranium, with high transmission and efficiency (P.N. Ostroumov and et al., Proc. of the PAC2001, p. 4080.). The initial section of the RIB linac is a low-charge-to-mass-ratio superconducting RF linac which will accelerate any ion with q/A>=1/66 to ~900 keV/u or higher. This section of the linac consists of many interdigital cavities operating at –20 degree synchronous phase and focusing can be provided by SC solenoids following each cavity. For the charge-to-mass ratio q/A=1/66 a proper focusing can be reached with the help of strong SC solenoid lenses with magnetic fields up to 15 T. These state-of-the-art solenoids are expensive. A possible lower cost alternative focusing method based on the combination of low-field SC solenoids and RF focusing is proposed and discussed in this paper.

TUPLT132	Investigation of Injection through Bending Magnet Fringe Fields in X-rays Source NESTOR	injection, dipole, storage-ring, vacuum	1434
	A. Mytsykov, P. Gladkikh, A.V. Rezaev, A.Y. Zelinsky NSC/KIPT, Kharkov
	In paper injection in the X-rays source NESTOR through fringe fields of a bending magnet is considered. The simulation of a motion of a beam of charged particles through 3-d fields of magnetic devices of the injection channel, which ones is located on a ring, are performed. The focusing properties of the injection channel are determined.

TUPLT138	A Fast Beam Chopper for Next Generation High Power Proton Drivers	emittance, proton, ion, beam-transport	1449
	M.A. Clarke-Gayther CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
	The identification and development of a successful beam chopper design is regarded as key for the European Spallation Source (ESS), and for all next generation high intensity proton driver schemes that adopt the linac-accumulator ring configuration. A description is given of refinements to the beam line design of a 'Tandem' chopper system, developed to address the requirements of the ESS. Particle tracking using the 'General Particle Tracer' (GPT) code has enabled efficient optimisation of beam apertures, and the analysis of beam power density distributions on chopper beam dumps. Preliminary results of 'proof of principle' testing on prototype fast, and slower transition high voltage pulse generators, are presented.

TUPLT147	Multiple-charge-state Beam Steering in High-intensity Heavy-ion Linacs	emittance, heavy-ion, focusing, beam-losses	1476
	E.S. Lessner, P.N. Ostroumov ANL/Phys, Argonne, Illinois
	An algorithm suitable for correction to steering of multiple-charge-state beams in heavy-ion linacs operating at high currents has been developed []. It follows a four-dimensional minimization procedure that includes coupling of the transverse beam motions. A major requirement is that it obeys the restricted lattice design imposed by the acceleration of multiple-charge-state heavy-ion beams []. We study the algorithm efficiency in controlling the beam effective emittance growth in the presence of random misalignments of cavities and focusing elements. Limits on misalignments are determined by quantifying beam losses and effective steering requirements are selected by examining several correcting schemes within the real-state constraints. The algorithm is used to perform statistically significant simulations to study beam losses under realistic steering. E. S. Lessner and P. N. Ostroumov, Proc. Part. Accel. Conf. (2003)** P. N. Ostroumov, Phys. Rev. STAB Vol. 5, 0030101 (2002)

TUPLT150	Vector Sum Control of an 8 GeV Superconducting Proton Linac	simulation, klystron, proton, controls	1482
	M. Huening, G.W. Foster Fermilab, Batavia, Illinois
	Fermilab is investigating the feasibility of an economical 8 GeV superconducting linac for H-. In order to reduce the construction costs it is considered to fan out the rf power to a string of accelerating structures per klystron. Below 1 GeV the individual fluctuations of the cavities will be compensated by high power phase shifters, above 1 GeV the longitudinal dynamics are sufficiently damped to consider omitting the phaseshifters. The impact of this setup on the field stability of individual cavities and ultimately the beam energy has been studied.

TUPLT162	Computation of the Longitudinal Space Charge Effect in Photoinjectors	simulation, space-charge, laser, bunching	1506
	C. Limborg-Deprey, P. Emma, Z. Huang, J.J. Welch, J. Wu SLAC, Menlo Park, California
	The LCLS Photoinjector produces a 100A, 10 ps long electron bunch which is later compressed down to 100 fs to produce the peak current required for producing SASE radiation. SASE saturation will be reached in the LCLS only if the emittance and uncorrelated energy spread remain respectively below 1.2 mm.mrad and 5. 10^-4. This high beam quality will not be met if the Longitudinal Space Charge (LSC) instability develops in the injector and gets amplified in the compressors. The Longitudinal Space Charge instability originates in the injector beamline, from an initial modulation of the current density. Numerical computations, performed with Multiparticle Space Charge tracking codes, showing the evolution of the longitudinal phase space along the LCLS Photoinjector beamline, are presented. Those results are compared with an analytical model for various regimes of energy and acceleration. This study justifies the necessity to insert a "laser heater" in the LCLS Photoinjector beamline to warm up the beam and thus prevent the amplification of the LSC instability in the compressors. Numerical calculations of the 'laser heater' performances are presented.

TUPLT167	Installation of the Spallation Neutron Source (SNS) Warm Linac	vacuum, alignment, site, quadrupole	1521
	P.E. Gibson, C. Deibele, J.J. Error, G.A.J. Johnson, P. Ladd ORNL/SNS, Oak Ridge, Tennessee N.K. Bultman LANL, Los Alamos, New Mexico
	The Spallation Neutron Source (SNS) is an accelerator-based neutron source being built at Oak Ridge National Laboratory. The SNS project design and construction is a partnership involving six DOE national laboratories including Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Oak Ridge, and Los Alamos. When completed in 2006, the SNS will provide the most intense, pulsed neutron beams in the world for scientific research and industrial development. At the present time we are installing and commissioning the warm linac system, designed by Los Alamos, and have to date had good success. The warm linac is comprised of six Drift Tube Linac (DTL) tanks and four Coupled Cavity Linac (CCL) modules. These accept an incoming negative hydrogen ion beam from the Front End injector at 2.5 MeV, and accelerate to a final energy of 185 MeV. At this time we have installed and commissioned DTL tanks 1-3 and installed CCL module 1 . Experience and information gained during installation will be presented. The performance in terms of alignment, vacuum and field tuning will be described.

TUPLT168	SNS Beam Commisioning Status	emittance, proton, target, beam-transport	1524
	S. Henderson, A.V. Aleksandrov, S. Assadi, W. Blokland, C. Chu, S.M. Cousineau, V.V. Danilov, G.W. Dodson, J. Galambos, M. Giannella, D.-O. Jeon, S. Kim, L.V. Kravchuk, M.P. Stockli, E. Tanke, R.F. Welton, T.L. Williams ORNL/SNS, Oak Ridge, Tennessee
	The Spallation Neutron Source accelerator systems will provide a 1 GeV, 1.44 MW proton beam to a liquid mercury target for neutron production. The accelerator complex consists of an H^- injector capable of producing 38 mA peak current, a 1 GeV linear accelerator, an accumulator ring and associated transport lines. The linear accelerator consists of a Drift Tube Linac, a Coupled-Cavity Linac and a Superconducting Linac which provide 1.5 mA average current to the accumulator ring. The staged beam commissioning of the accelerator complex is proceeding as component installation progresses. In three separate beam commissioning runs, the H^- injector and Drift Tube Linac tanks 1-3 have been commissioned at ORNL. Several important performance goals have been achieved, namely 38 mA peak beam current, 1 msec beam pulse length and 1 mA average beam current. Results and status of the beam commissioning program will be presented.

TUPLT170	The SNS Beam Power Upgrade	extraction, space-charge, kicker, klystron	1527
	S. Henderson, S. Assadi, R. Cutler, V.V. Danilov, G.W. Dodson, R.E. Fuja, J. Galambos, J.A. Holmes, N. Holtkamp, D.-O. Jeon, S. Kim, L.V. Kravchuk, M.P. McCarthy, G.R. Murdoch, D.K. Olsen, T.J. Shea, M.P. Stockli ORNL/SNS, Oak Ridge, Tennessee
	The Spallation Neutron Source (SNS) accelerator systems, which consist of an H^- injector, a 1 GeV linear accelerator, an accumulator ring and associated transport lines, will provide a 1 GeV, 1.44 MW proton beam to a liquid mercury target for neutron production. The SNS is presently under construction at Oak Ridge National Laboratory and will begin operations in 2006. Even in the baseline design, many of the accelerator subsystems are capable of supporting higher beam intensities and higher beam energy. We report on upgrade scenarios for the SNS accelerator systems which increase the 1.44 MW baseline beam power to at least 3 MW, and perhaps as high as 5 MW. The increased SNS beam power can be achieved primarily by increasing the H^- ion source current, installing additional superconducting cryomodules to increase the final linac beam energy to 1.3-1.4 GeV, and modifying injection and extraction hardware in the ring to handle the increased beam energy. The upgrade beam parameters will be presented, the required hardware modifications will be described, and the beam dynamics implications will be discussed.

TUPLT171	ORBIT Simulations of the SNS Accumulator Ring	simulation, injection, electron, space-charge	1530
	J.A. Holmes, S.C. Bunch, S.M. Cousineau, V.V. Danilov, S. Henderson, A. Shishlo ORNL/SNS, Oak Ridge, Tennessee M. Plum LANL, Los Alamos, New Mexico Y. Sato IUCF, Bloomington, Indiana
	As SNS undergoes construction, many detailed questions arise concerning strategies for commissioning and operating the accumulator ring. The ORBIT Code is proving to be an indispensible tool for addressing these questions and for providing guidance to the physicists and decision makers as operation draws near. This paper shows the application of ORBIT to a number of ring issues including exclusion of the HEBT RF cavities during commissioning, the detailed effect of the injection chicane magnets on the beam, the effects and correction of magnet alignment and multipole errors, debunching of the linac 402.5 MHz beam structure, the injection of self consistent uniform beam configurations, and initial electron cloud simulations.

TUPLT172	Measurement of Halo Mitigation Schemes for the Spallation Neutron Source Linac	optics, emittance, simulation, beam-losses	1533
	D.-O. Jeon ORNL/SNS, Oak Ridge, Tennessee
	A series of emittance measurements were performed at the end of Drift Tube Linac tank 1 of the Spallation Neutron Source to verify experimentally the previously proposed halo generation mechanism and its mitigation schemes [1]. The emittance measurements clearly showed a visible reduction in the halo as well as a significant reduction in the rms emittance when the proposed round beam optics is employed. This confirms experimentally the halo generation mechanism we identified.

TUPLT173	Experimental Test of Transverse Matching Routine for the SNS Linac	emittance, optics, beam-losses, quadrupole	1536
	D.-O. Jeon, S. Assadi ORNL/SNS, Oak Ridge, Tennessee J. Stovall LANL, Los Alamos, New Mexico
	Transverse matching for a high intensity linac was proposed based on minimizing rms emittances. A MATLAB routine was developed and applied during the SNS linac commissioning. The result was also compared with the simulations.

TUPLT186	Managing System Parameters for SNS Magnets and Power Supplies	power-supply, target, vacuum, controls	1565
	W.J. McGahern, S. Badea, F.M. Hemmer, H.-C. Hseuh, J.W. Jackson, A.K. Jain, F.X. Karl, R.F. Lambiase, Y.Y. Lee, C.J. Liaw, H. Ludewig, G.J. Mahler, W. Meng, C. Pai, C. Pearson, J. Rank, D. Raparia, J. Sandberg, S. Tepikian, N. Tsoupas, J. Tuozzolo, P. Wanderer, J. Wei, W.-T. Weng BNL, Upton, Long Island, New York R. Cutler, J.J. Error, J. Galambos, M.P. Hechler, S. Henderson, P.S. Hokik, T. Hunter, G.R. Murdoch, K. Rust, J.P. Schubert ORNL/SNS, Oak Ridge, Tennessee
	The Spallation Neutron Source (SNS), currently under construction at Oak Ridge, Tennessee, is a collaborative effort of six U.S. Department of Energy partner laboratories. With over 312 magnets and 251 power supplies that comprise the beam transport lines and the accumulator ring, it is a challenge to maintain a closed loop on the variable parameters that are integral to these two major systems. This paper addresses the input variables, responsibilities and design parameters used to define the SNS magnet and power supply systems.

WEOACH03	Achievement of 35 MV/m in the TESLA Superconducting Cavities Using Electropolishing as a Surface Treatment	electron, superconductivity, collider, coupling	129
	L. Lilje DESY, Hamburg
	The Tera Electronvolt Superconducting Linear Accelerator TESLA is the only linear electron-positron collider project based on superconductor technology for particle accelaration. In the first stage with 500 GeV center-of-mass energy an accelerating field of 23.4MV/m is needed in the superconducting niobium cavities which are operated at a temperature of 2 K and a quality factor Q0 of 10¹⁰. This performance has been reliably achieved in the cavities of the TESLA Test Facility (TTF) accelerator. The upgrade of TESLA to 800 GeV requires accelerating gradients of 35 MV/m. Using an improved cavity treatment by electrolytic polishing it has been possible to raise the gradient to 35 - 43 MV/m in single cell resonators. Here we report on the successful transfer of the electropolishing technique to multi-cell cavities. Presently four nine-cell cavities have achieved 35 MV/m at Q_0 = 5 × 10⁹, and a fifth cavity could be excited to 39 MV/m. In two high-power tests it could be verified that EP-cavities preserve their excellent performance after welding into the helium cryostat and assembly of the high-power coupler. One cavity has been operated for 1100 hours at the TESLA-800 gradient of 35 MV/m and 57 hours at 36 MV/m without loss in performance.
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WEYCH02	Technical Issues for Large Accelerators based on High Gradient SC Cavities	electron, collider, vacuum, radiation	137
	C. Pagani, C. Pagani DESY, Hamburg
	The perspective to build large accelerators based on high gradient superconducting cavities is posing a number of new problems that have been addressed in the preparation of the TESLA project. Starting from the experience gained with the past large installations, such as LEP2 at CERN and CEBAF at JLab, in this paper I discuss the new demands and the solution envisaged. Industrial production issues are focussed in terms of large scale production, reviewed quality control criteria and cost reduction. The impact on component design and engineering together with the expected improvements in term of performances and reliability are also outlined.
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WEYCH03	Low and Medium Beta Superconducting Cavities	proton, ion, heavy-ion, beam-loading	142
	A. Facco INFN/LNL, Legnaro, Padova
	The use of low- and intermediate-beta superconducting cavities, once confined to low current heavy ion linacs, is steadily increasing in accelerators. The progress in this technology allowed a significant increase in cavity performance during the last 10 years; a large number of resonators, with different geometries, frequencies and gap numbers have been built for a large variety of applications and the development is still going on. The main boost is given by new projects of radioactive beam facilities and high power proton accelerators worldwide. While the advantages of SC resonators, compared with normal conducting structures, are rather well established in high-beta linacs, this is not always the case at low-beta. The choice of the optimum transition beam energy in a linac, where superconducting cavities should replace the room temperature ones, requires a careful evaluation that depends on the linac specifications.
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WEOBCH02	Design, Construction, and Initial Operation of the SNS MEBT Chopper System	target, beam-transport, rfq, extraction	150
	R.A. Hardekopf, S.S. Kurennoy, J. Power LANL, Los Alamos, New Mexico A.V. Aleksandrov, D.E. Anderson ORNL/SNS, Oak Ridge, Tennessee
	The chopper system for the Spallation Neutron Source (SNS) provides a gap in the beam for clean extraction from the accumulator ring. It consists of a pre-chopper in the low-energy beam transport (LEBT) and a faster chopper in the medium-energy beam transport (MEBT). We report here on the final design, fabrication, installation, and first beam tests of the MEBT chopper. The traveling-wave deflector is a meander-line design that matches the propagation of the deflecting pulse with the velocity of the beam at 2.5 MeV, after the radio-frequency quadrupole (RFQ) acceleration stage. The pulser uses a series of fast-risetime MOSFET transistors to generate the deflecting pulses of ± 2.5 kV with rise and fall times of 10 ns. We describe the design and fabrication of the meander line and pulsers and report on the first operation during initial beam tests at SNS.
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WEOCCH01	A New 180 MeV H^- Linac for Upgrades of ISIS	quadrupole, synchrotron, emittance, injection	153
	F. Gerigk CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
	Several options have been studied to raise the beam power of the ISIS spallation neutron source to a level of 1 MW with the possibility of going to 4-5 MW in the longer term. All scenarios can operate in 2 modes, where the beam power is either delivered to a spallation target or, alternatively, to a target suitable to produce muons via pion decay for a neutrino factory. A more recent upgrade option takes an intermediate step and uses a 180 MeV H^- linac, which is also foreseen for the 4-5 MW upgrade, as a replacement for the current 70 MeV injector. First estimates indicate that, due to the lower space charge forces, the ring would be able to carry twice as many particles, thus doubling the final beam power to 0.5 MW. This paper presents a first design for the 180 MeV linac, using a triple frequency jump from 234.8 to 704.4 MHz. The design profits from the development of 704.4 MHz cavities and RF equipment within the framework of the European HIPPI collaboration. The low frequency for the front-end was chosen to ease the DTL design as well as the development of a low energy beam chopper, which will be necessary to reduce beam losses at injection into the synchrotron.
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WEODCH01	1.5-GeV FFAG Accelerator as Injector to the BNL-AGS	injection, acceleration, lattice, proton	159
	A. Ruggiero, M. Blaskiewicz, T. Roser, D. Trbojevic, N. Tsoupas, W. Zhang BNL, Upton, Long Island, New York
	A 1.5-GeV Fixed-Field Alternating-Gradient (FFAG) Accelerator has been recently proposed as a new injector to the Alternating-Gradient Synchrotron (AGS) of Brookhaven National Laboratory (BNL). It is being considered as a replacement of the present 1.5-GeV AGS Booster. The substitution will enhance the performance of the AGS accelerator facility in a variety of ways. It would still allow acceleration of all hadronic particles: protons, and heavy-ions. The major benefit is that it would considerably shorten the typical combined AGS acceleration cycle, and, consequently, may yield to an improvement of beam stability, intensity and size. The AGS-FFAG will also facilitate the proposed upgrade of the AGS facility toward a 1-MW average proton beam power. The paper describes a compact FFAG design for acceleration of protons from 200 MeV to 1.5 GeV. The circumference is about 250 m. The lattice is a periodic sequence of FDF triplets of combined-function magnets. An adjusted field profile has been calculated to compensate the variation of the main lattice functions with momentum. At injection, a beam pulse 130 μs long of negative-ions (H?) is stacked with the charge-exchange method. Acceleration of one pulse with 2.5 x 10¹³ protons takes about 130 μs, if harmonic-jump scheme is used in conjunction with the choice of 201.25 MHz. Four of such beam pulses are required to fill entirely the AGS. The entire filling process thus takes less than one millisecond.
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WEYLH01	Emittance Control for Very Short Bunches	emittance, impedance, undulator, simulation	179
	K.L.F. Bane SLAC, Menlo Park, California
	Many recent accelerator projects call for the production of high energy bunches of electrons or positrons that are simultaneously short, intense, and have small emittances. Two examples of such projects are linear colliders, such as the GLC/NLC, and Self-Amplified Spontaneous Emission (SASE) FEL's, such as the Linac Coherent Light Source (LCLS). A major challenge in such projects is keeping in check forces that increase short bunch emittances in accelerator components, such as: wakefields of accelerator structures, collimators, and surface roughness, and coherent synchrotron radiation (CSR). We describe such forces and their control.
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WEILH00	Industrial Involvement in EC Supported Accelerator R&D in the 6th Framework Programme and in Preparing Large Scale Accelerator Projects	electron, vacuum, proton, klystron	194
	D. Proch DESY, Hamburg
	The presentation will cover industrial involvement in EC supported accelerator R&D in the 6th framework programme and in preparing large scale accelerator projects (TESLA).
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WEPKF003	Design of the End Magnets for the IFUSP Main Microtron	microtron, booster, magnet-design, electron	1591
	M.L. Lopes, A.A. Malafronte, M.N. Martins, J. Takahashi USP/LAL, Bairro Butantan K.-H. Kaiser IKP, Mainz
	The Instituto de Física da Universidade de São Paulo (IFUSP) is building a two-stage 31 MeV continuous wave (cw) racetrack microtron. In this work we describe the characteristics of the end magnets for the IFUSP main microtron. The magnets are part of the main acceleration stage, which raises the energy from 4.9 to 31 MeV. We are studying the possibility of increasing the energy up to 38 MeV, so the magnets should have approximately 2x1 m2 region of useful field. The dipoles have a 0.1410 T magnetic field and 1 part in 1000 homogeneity without correcting devices. Using a 2D magnetic field code (FEMM), we illustrate the use of homogenizing gaps with different forms and non parallel pole faces to achieve the necessary homogeneity. The use of clamps to produce reverse fields to reduce the vertical defocusing strength on the beam is also described. In order to calculate the beam trajectories and to evaluate the magnetic field homogeneity within the useful region, a 3D magnetic field software (TOSCA) was used.

WEPKF018	Beam-loss Induced Pressure Rise of LHC Collimator Materials Irradiated with 158 GeV/u In⁴⁹⁺ Ions at the CERN SPS	ion, vacuum, heavy-ion, beam-losses	1633
	E. Mahner, I. Efthymiopoulos, J. Hansen, E. Page, H. Vincke CERN, Geneva
	During heavy ion operation, large pressure rises, up to a few orders of magnitude, were observed at CERN, GSI, and BNL. The dynamic pressure rises were triggered by lost beam ions that impacted onto the vacuum chamber walls and desorbed about 10⁴ to 10⁷ molecules per ion. The deterioration of the dynamic vacuum conditions can enhance charge-exchange beam losses and can lead to beam instabilities or even to beam abortion triggered by vacuum interlocks. Consequently, a dedicated measurement of heavy-ion induced molecular desorption in the GeV/u energy range is important for LHC ion operation. In 2003, a desorption experiment was installed at the SPS to measure the beam-loss induced pressure rise of potential LHC collimator materials. Samples of bare graphite, sputter coated (Cu, TiZrV) graphite, and 316 LN stainless steel, were irradiated under grazing angle with 158 GeV/u indium ions. After a description of the new experimental set-up, the results of the pressure rise measurements are presented, and the derived desorption yields are compared with data from other experiments.

WEPKF031	Magnetic Field Correction of the Bending Magnets of the 1.5 GeV HDSM	dipole, microtron, electron, coupling	1669
	F. Hagenbuck, P. Jennewein, K.-H. Kaiser IKP, Mainz
	Beam dynamics of the Harmonic Double Sided Microtron (HDSM), the fourth stage of MAMI, require a very precise magnetic field in the inhomogeneous bending magnets. By measuring the vertical field component By in and on both sides of the midplane, the complete set of field components Bx, By, Bz was determined in the whole gap. Starting from this the asymmetric pole surface current distribution necessary to correct both symmetric and antisymmetric field errors was calculated. However, tracking calculations showed that the influence of skewed field components on the beam deflection are negligible, so that symmetric field corrections are sufficient. Nevertheless, in order to demonstrate the functioning, a set of asymmetric correction coils was built and successfully tested. The symmetric coils are designed to reduce field errors below 2*10-4. Deflection errors in the fringe field region near the magnet corners, which cannot be corrected by surface currents, will be compensated by vertical iron shims in combination with small dipoles on each beam pipe.

WEPKF035	Analysis of the Cold Mass Displacements at the TTF	quadrupole, alignment, monitoring, vacuum	1681
	A. Bosotti, C. Pagani, P. Pierini INFN/LASA, Segrate (MI) R. De Monte, M. Ferianis ELETTRA, Basovizza, Trieste R. Lange DESY, Hamburg
	Few of the TTF cryomodules have been equipped with wire position monitors (WPM) in order to monitor on line the displacements of the cold mass to verify alignment stability and reproducibility . Based on the operation experience of the first prototypical cryomodules, equipped with up to 36 WPMs distributed in two strings, on the last generation cryomodules a single string of 7 sensors has been installed. Here we review and analyze the data collected so far to prove that the the proposed cryomodule design is consistent with the TESLA alignment requirements.

WEPKF050	Measurement of Fast High Voltage Pulse and High Noisy DC Siganla for Modulator at the PLS Linac	vacuum, klystron, electron, monitoring	1717
	S.-C. Kim, Y.J. Han, S.H. Kim, S.-H. Nam, S.S. Park PAL, Pohang
	The 2.5-GeV electron linac at Pohang accelerator laboratory (PAL) has been operated continuously as a full energy injector for the Pohang Light Source (PLS) since Dec. 1994. There have been continuous efforts to improve the klystron-modulator system more stable and reliable. At pulse operated modulator system, important pulse and DC signals are beam voltage, beam current, EOLC current HVDC voltage and HVDC current. Pulse signals are fast high voltage pulse 30 Hz, 5ms. These signals are adequate level down from modulator but including high level switching noisy. To amplitude measure of these signals for every trigger signal, we developed special module sampling hold, A/D, calculating and D/A. The output signals of these modules are 0 ~ 10 V DC signal and not include any noise signal. These output signals are connected interlock interface module of the modulator controller. Therefore computer system (PC) of the modulator controller is free to noise of these signals and can precise monitor pulse & noise DC signal. In these paper, we are described itself characteristics pulse and high noisy DC signals of the modulator, signal conditioning technique after noise elimination and operation status of the modulator controller.

WEPKF051	Operational Analysis of PLS 2-GeV Electron Linac Klystron-modulator System	klystron, electron, vacuum, impedance	1720
	S.S. Park, Y.J. Han, S.H. Kim, S.-C. Kim, S.-H. Nam PAL, Pohang
	The klystron-modulator(K&M) system of the Pohang Light Source(PLS) had been supplying high power microwaves for the acceleration of 2 GeV electron beams. There are 11 sets of K&M systems to accelerate electron beams to 2 GeV nominal beam energy without operating one klystron-modulator. One module of the K&M system consists of an 80 MW S-band (2856 MHZ) klystron tube and the matching 200 MW modulator. The total accumulated high-voltage run-time of the oldest unit among the 12 K&M systems has reached nearly 68,000 hours as of Dec. 2003 and the summation of all the units' high voltage run-time is approximately 820,000 hours. The overall system availability is well over 95%. There have been continuous efforts to improve the klystron-modulator system more stable and reliable. To improve self-diagnostic, operation, monitoring, and remote communication, we developed a new modulator controller based on an industrial PC platform in 2002. In this paper, we are able to review overall system performance of the high-power K&M system and the operational characteristics of the klystrons and thyratrons, and overall system's availability analysis from Jan. to Dec. 2003.

WEPKF053	Status and Development for the JAERI ERL-FEL for High-Power and Long-Pulse Operation	coupling, pick-up, feedback, undulator	1723
	M. Sawamura, R. Hajima, N. Kikuzawa, E.J. Minehara, R. Nagai, N. Nishimori JAERI/FEL, Ibaraki-ken
	After the success of energy recovery linac (ERL) for the superconducting free-electron laser (FEL) in the Japan Atomic Energy Research Institute (JAERI), the JAERI ERL-FEL has been upgrading for high-power and long-pulse operation. The new grid pulser for the thermoionic cathode gun is under development and test to increase the beam current by increasing the repetition rate of 10MHz to 20MHz. The new RF sources of CW mode for higher power for non-energy-recovery parts have been installed and tested for long-pulse operation. The properties of the superconducting linac required for the long-pulse operation were also measured such as pressure in the cryomodule, vibration of frequency and piezo tuner response. The RF control systems have been also upgraded to reduce the fluctuation to less than 0.1% for amplitude and 0.1 deg for phase.

WEPKF069	52 kV Power Supply for Energy Recovery Linac Prototype RF	klystron, power-supply, cathode, vacuum	1762
	J.E. Theed, M. Dykes, A. Gallagher, S.A. Griffiths, S.H. Hands, A.J. Moss, J.F. Orrett, C.J. White CCLRC/DL, Daresbury, Warrington, Cheshire
	Daresbury Laboratory is constructing a Radio-Frequency (RF) Test Facility to be capable of testing RF cavities for accelerator applications. Electrical power for the RF equipment will be provided from an existing -52 kV 6-pulse rectifier and transformer system capable of delivering 16A DC continuous current. A crowbar circuit will be provided to divert the large amount of stored energy in the smoothing capacitor bank in the event that a spark should occur between the cathode and the body or modulating anode. Traditionally, the crowbar has been provided by using an ignitron, but modern solid state devices have sufficient performance to meet the requirements. This paper discusses the numerous design options that were considered for the circuit parameters.

WEPKF079	A Kicker Design for the Rapid Transfer of the Electron Beam between Radiator Beamlines in LUX	electron, septum, kicker, injection	1786
	G.D. Stover LBNL/ALS, Berkeley, California
	I present in this paper preliminary design concepts for LUX - A ?fast kicker design for rapid transfer of the electron beam between radiator beamlines. This paper is a very simple feasibility study to find a rougly optimized subset of engineering parameters that would satisfy the initial design specifications of: Pulse width < 30us, time jitter < 1ns, magnetic length < 0.5meter, gap hight = 15mm, gap width = 25mm, peak field = .6Tesla, bend angle = 1.7 deg. for beam energy of 3.1 Gev, repetition rate = 10KHz. An H magnet core configuration was chosen. Through an iterative mathematical process a realizable design was chosen. Peak current, Peak voltages across the coils, conductor losses due to proximity and skin effects, di/dt rates, eddy and beam current heating in the ceramic vacuum chamber, and basic circuit topology were investigated. Types and losses of core material were only briefly discussed. The final topology consists of two magnets in series running at 10KHz, .3Tesla, 630 amp peak current, 10us pulse width, 364 Watts per coil section, driven by fast solid state switch with an energy recovery inductor. Eddy and beam image current losses were ~ 164 watts.

WEPKF081	Prototype Development Progress toward a 500kV Solid State Marx Modulator	klystron, cathode, linear-collider, simulation	1792
	G. Leyh SLAC, Menlo Park, California
	Recent advances in high voltage IGBT capabilities have made possible a range of novel solid-state modulator concepts that were unthinkable a decade ago. At present, there are two prototype solid-state modulator designs under evaluation at SLAC – A conventional pulse-transformer design using an 80kV solid-state switch in place of a thyratron, and an 'induction modulator', which uses a stack of magnetic cores to couple many paralleled primary windings to a common secondary winding. Both of these prototype modulators are currently driving actual klystron loads at SLAC. Another promising solid-state modulator concept still in the early stages of development is the Marx configuration – where an array of stacked modules generates high-voltage output pulses directly from a low DC input supply voltage. This scheme eliminates the large and costly magnetic cores inherent in the other two designs, resulting in a considerably simpler and cheaper mechanical solution. The main disadvantage to this approach is that the individual Marx sections must float at high voltages, complicating the distribution of power and timing signals. Several research groups have produced limited scale Marx prototypes in recent years. The largest prototype built to date [DTI] generates an output pulse of approximately 50kV, with plans to eventually move to higher voltage levels. This paper examines in closer detail the practical advantages and pitfalls of a solid-state Marx configuration, and explores a design approach with emphasis on performance, wall-plug efficiency, cost of manufacture, availability and ease of service. The paper presents electrical diagrams, mechanical CAD layout and preliminary prototype test data.

WEPKF086	A Model for Determining Dipole, Quadrupole and Combined Function Magnet Costs	dipole, quadrupole, superconducting-magnet, diagnostics	1807
	R. Palmer, J.S. Berg BNL, Upton, Long Island, New York
	One of the most important considerations in designing large accelerators is cost. Magnet costs are a significant component of that. This paper describes a model for estimating magnet costs. The reasoning behind the cost model is explained, and the parameters of the model are chosen so as to correctly give the costs for existing magnets.

WEPLT028	High-intensity and High-density Charge-exchange Injection Studies into the CERN PS Booster at Intermediate Energies	injection, simulation, space-charge, emittance	1891
	M. Martini CERN, Geneva C.R. Prior CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
	For the high brilliance LHC ultimate beam and the high intensity CNGS beam, single batch injections into the CERN Proton Synchrotron (PS) will be used to increase the overall machine intensity compared with the present double batch injections. Charge-exchange injection into the PS Booster with a new linac at intermediate energies is thus examined. A key parameter to consider is the energy dependence of beam incoherent tune shifts at injection. Increasing the linac energy from the present 50 MeV to 160 MeV should yield a safer tune shift. For each PS Booster ring, a charge-exchange injection scheme is envisaged inside a proper straight section, redesigned with new bends to make a local bump and using the existing fast bump magnets for horizontal phase-space painting. ACCSIM simulations for charge-exchange injection at 160 MeV have been investigated for both LHC and CNGS beams. After optimizing the parameters that are used for the space charge tracking routines, the results of the simulations agree well with expectations, signifying that the LHC ultimate and CNGS beams may be provided with single PS Booster batches within the required emittances. For assessment, simulation of injection at 50 MeV for the current LHC beam has been performed, yielding a fairly good agreement with measured performance. Concurrently, similar charge-exchange injection simulations have been carried out using an alternative programme developed at the Rutherford Appleton Laboratory.

WEPLT058	A Space Charge Algorithm for Ellipsoidal Bunches with Arbitrary Beam Size and Particle Distribution	space-charge	1975
	G. Franchetti, A. Orzhekovskaya GSI, Darmstadt
	For the GSI future project beam loss control of a high intensity bunched beam stored in SIS100 for 10⁶ turns is an important issue. In a recent study (G. Franchetti et al., Phys. Rev. ST Accel. Beams 6, 124201 (2003)) an analytical space charge algorithm was proposed, which allowed noise-free calculations over a large number of turns. Here we present a generalization of this algorithm to arbitrary 3D dimensions and arbitrary distributions observing ellipsoidal symmetry. Applications to long-term tracking with space charge are presented

WEPLT062	Wakefield Calculations for TTF-II	impedance, electromagnetic-fields, diagnostics, dipole	1987
	I. Zagorodnov, T. Weiland TEMF, Darmstadt M. Dohlus DESY, Hamburg
	In this paper we estimate long- and short-range wake functions for new elements to be used in TESLA Test Facility (TTF) - II. The wake potentials of the LOLA-IV structure and the 3rd harmonic section are calculated numerically for very short bunches and analytical approximations for wake functions in short and long ranges are obtained by fitting procedures based on analytical estimations. The numerical results are obtained with code ECHO for high relativistic Gaussian bunches with RMS deviation up to 0.015 mm. The calculations are carried out for the complete structures (including bellows, rounding of the irises and the different end cell geometries) supplied with ingoing and outgoing pipes. The low frequency spectra of the wake potentials is calculated using the Prony-Pisarenko method.

WEPLT065	Hybrid Dry Coolers in Cooling Systems of High Energy Physics Accelerators	simulation, synchrotron, site	1996
	J.-P. Jensen, B. Conrad, U. Schuetz, F.-R. Ullrich, A. Wanning DESY, Hamburg
	Wet water cooling towers in high energy physics accelerators are state of the art. The advantages are robustness, effectiveness and cost-effectiveness. The return water temperature is lower than the air temperature due to cooling via evaporation. The disadvantages are the high water consumption, which becomes more costly in the future, and the soiling of the heat exchangers. If the water source is taken from wells then the drawdown of the ground water level has to be taken into account. DESY plans to use hybrid dry coolers for the two future projects: The XFEL linac and the PETRA 3 synchrotron light source. A hybrid dry cooler is a combination of a dry air cooler during cold and moderate seasons and additional wet cooling during the hot summer season. The cooling surface is wetted by adding water to increase the cooling capability by a factor of 250 %. The hybrid dry cooler saves a lot of water. The water consumption can be reduced by 70% compared to a wet cooling system. This contribution presents the auxiliary water consumption, the requirement of this water and an estimate of the temperature control behaviour of the hybrid dry cooling system.

WEPLT067	Space Charge Problem in Low Energy Super-conducting Accelerator	focusing, space-charge, resonance, simulation	2002
	N.E. Vasyukhin, R. Maier, Y. Senichev FZJ/IKP, Jülich
	At present the super-conducting option of linear accelerators is considered for low energy, and new type of RF cavities is considered for this purpose. However, together with electrodynamics problems we should solve the transverse stability problem, since in structures with external focusing elements the focusing period is longer, and in higher accelerating field the defocusing factor increases as well. In this paper we consider the transverse stability problem, taking into account the non-linear space charge problem. The fundamental mechanism of hallo creation in super-conducting linear accelerators is investigated to minimize the particle losses. The theoretical results are supported by numerical simulation.

WEPLT071	Longitudinal Resonances and Emittance Growth Using QWR/HWR in a Linac	resonance, emittance, focusing, transverse-dynamics	2014
	P. Bertrand GANIL, Caen
	In the frame of the SPIRAL II project at GANIL, we present an analytical approach allowing us to understand in a simple way the longitudinal behaviour of a beam , transmitted in bunching mode or accelerated in a Linac designed with QWR or HWR cavities. In particular, we make appear the strong relationship with the Henon map properties.

WEPLT072	Preliminary Design of the RF Systems for the SPIRAL 2 SC Linac	beam-loading, rfq, feedback, coupling	2017
	M. Di Giacomo, B. Ducoudret, J.F. Leyge GANIL, Caen J.F. Denis, M. Desmons, M. Luong, A. Mosnier CEA/DSM/DAPNIA, Gif-sur-Yvette
	In the SPIRAL 2 Linac, a 5 mA, CW , Deuteron beam is accelerated up to 40 MeV, through a normal conducting RFQ and 26 independent-phase SC quarter wave resonators, working at 88,05 MHz. Tube and solid state amplifiers derived from the standard FM transmitter modules are used while a new digital control system has been designed for the feed-back and feed-forward control system. The paper presents the power and low level systems for both the normal and superconducting cavities and results of simulations of the RF system in operating conditions.

WEPLT073	VDHL Design and Simulation of a Fast Beam Loss Interlock for TTF2	beam-losses, single-bunch, simulation, electron	2020
	A. Hamdi CEA/Saclay, Gif-sur-Yvette M. Luong CEA/DSM/DAPNIA, Gif-sur-Yvette M. Werner DESY, Hamburg
	The TTF2 fast beam loss interlock provides different modes of protection. Based on the differential beam charge monitoring over a macropulse, a pulse slice or bunch-by-bunch, the signal processing time should be as short as the bunch repetition period (110 ns). The signal delivered by the toroid-like inductive current transformer always shows an envelope droop due to its self-inductance to resistance ratio. When the macropulse length is comparable to this ratio, the charge of each bunch must be derived from the difference of the top to the bottom level on the signal. This necessity combined to the various protection modes leads to a digital implementation. All the processing functionalities are designed with VHDL for a Xilinx FPGA. Because the interlock involves other control signals in addition to the toroid signal with specific shapes, which cannot be easily reproduced for the design validation before the TTF2 completion, VHDL provides meanwhile the possibility for an exhaustive validation of the system with a software test bench including all timing information.

WEPLT075	Status Report on the Beam Dynamics Developments for the SPIRAL 2 Project	quadrupole, ion, rfq, dipole	2023
	R. Duperrier, D. Uriot CEA/DSM/DAPNIA, Gif-sur-Yvette P. Bertrand, F. Varenne GANIL, Caen J.-L. Biarrotte IPN, Orsay J.-M. De Conto ISN, Grenoble E. Froidefond LPSC, Grenoble N. Pichoff CEA/DAM, Bruyères-le-Châtel
	The driver for the SPIRAL 2 project aims to accelerate a 5 mA D⁺ beam up to 20 A.MeV and a 1 mA beam for Q/A=1/3 up to 14.5 A.MeV. It operates in a continuous wave regime (cw), is designed for a maximum efficiency in the transmission of intense beams. Recent studies have led to change the reference design. The current design consists in an injector (ECR sources + LEBTs with the possibility to inject from several sources + a Radio Frequency Quadrupole) followed by a superconducting section based on an array of independently phased cavities where the transverse focalisation is performed by warm quadrupoles. This paper presents the beam dynamics studies associated to these new choices, the HEBT design and the fast chopping in the MEBT.

WEPLT078	The IFMIF High Energy Beam Transport Line	target, octupole, simulation, space-charge	2032
	D. Uriot, R. Duperrier, J. Payet CEA/DSM/DAPNIA, Gif-sur-Yvette
	The IFMIF project (International Fusion Materials Irradiation Facility) requests two linacs designed to accelerate 125 mA deuteron beams up to 40 MeV. The linac has to work in CW mode and uses one RFQ and 10 DTL tanks. After extraction and transport, the deuteron beams with strong internal space charge forces have to be bunched, accelerated and transported to target for the production of high neutron flux. This paper presents the high energy beam transport line which provides a flat rectangular beam profile on the liquid lithium target. Transverse uniformisation is obtained by using non-linear mutipole lenses (octupoles and duodecapoles). Beam dynamics with and without errors has been study.

WEPLT086	Non Gaussien Transverse Distributions in a Stochastic Model for Beam Halos	space-charge, emittance, simulation, beam-losses	2056
	N. Cufaro Petroni INFN-Bari, Bari S. De Martino, S. De Siena, F. Illuminati Universita' degli Studi di Salerno, Dipartimento di Fisica E.R. Caianiello, Baronissi
	The formation of the beam halo in charged particle accelerators is studied in a dynamical stochastic model for the collective motion of the particle beam. The density and the phase of the charged beam obey a set of coupled nonlinear hydrodynamic equations with time-reversal invariance. The linearized theory for this collective dynamics is given in terms of a classical Schroedinger equation. Self-consistent solutions with space-charge effects lead to quasi-stationary beam configurations with enhanced transverse dispersion and transverse emittance growth. In the limit of a frozen space-charge core it is possible to determine and study the properties of stationary, stable core-plus-halo beam distributions. We explore the effect of non-Gaussian transverse distributions. In this case the underling stochastic process is allowed to jump, and the transverse distribution tails are heavier than in the Gaussian case giving rise to a halo effect. The stationary transverse distribution plays the role of an attractor for every other distribution, and we give an estimation of the time needed by a non stationary, halo-free distribution to relax toward the stationary distribution with a halo.

WEPLT097	Beam Loading in the RF Deflector of the CTF3 Delay Loop	beam-loading, injection, emittance, simulation	2077
	D. Alesini, F. Marcellini INFN/LNF, Frascati (Roma)
	In this paper we describe the impact of the beam loading in the RF deflectors on the transverse beam dynamics of the CTF3 Delay Loop. The general expression for the single passage wake field is obtained. A dedicated tracking code has been written to study the multi-bunch multi-turn effects on the transverse beam dynamics. A complete analysis for different machine parameters and injection errors is presented and discussed. The numerical simulations show that the beam emittance growth due to the wake field in the RF deflectors is small.

WEPLT101	On-line Mechanical Instabilities Measurements and Tuner Development in SC Low-beta Resonators	feedback, vacuum, injection, resonance	2086
	A. Facco, E. Bissiato, S. Canella, D. Carlucci, M. Lollo, F. Scarpa, D. Zenere INFN/LNL, Legnaro, Padova
	The use of high-Q and small rf bandwidth superconducting quarter wave resonators made of bulk niobium put severe requirements to the helium bath pressure stability to avoid cavity detuning. This is not always possible, and cavity detuning caused by slow pressure changes must be precisely followed by the cavity tuner. The LNL philosophy is based on mechanical damping of cavity vibrations and mechanical tuning in feedback for slow frequency compensation. The old-fashioned tuners installed in the ALPI linac had significant performance limitations. To replace them, we have designed, constructed and tested a new tuner which integrates the LNL system and control with the TRIUMF, backlash-free tuner leverage design. The new tuner is designed to compensate pressure changes up to 100 mbar/minute with a precision of 0.5 Hz, and it will be installed in the ALPI resonators. An upgraded prototype for future applications includes a piezoelectric actuator for fast tuning. Tuner characteristics and first test results will be presented. This system is extendable to other low-beta cavity types like superconducting rfqs.

WEPLT103	Radiation Damage in Magnets for Undulators at Low Temperature	radiation, electron, undulator, permanent-magnet	2092
	T. Bizen, X. Maréchal, T. Seike JASRI/SPring-8, Hyogo Y. Asano JAERI/SPring-8, Hyogo T. Hara, H. Kitamura, T. Tanaka RIKEN Spring-8 Harima, Hyogo D.E. Kim, H.S. Lee PAL, Pohang
	Nd2Fe14B permanent magnets are used in many insertion devices for its good magnetic and mechanical properties. However, the radiation sensitivity of the magnets would be concern when they are used in a strong radiation environment. It is known that these magnets with very high coercivity show high resistance to radiation, though the substance for increasing the coercivity decrease the remanence. The coercivity and remanence of this magnet exhibit negative dependence against temperature, so it is expected to these magnets to show high remanence and high resistance to radiation at low temperature. The idea of using magnets at low temperature leads the new concept of the cryogenic undulators. In this report, the experimental results of the radiation damage of permanent magnets at low temperature are shown.

WEPLT145	Beam Loss Studies in High-intensity Heavy-ion Linacs	simulation, beam-losses, emittance, ion	2176
	P.N. Ostroumov, V.N. Aseev, E.S. Lessner, B. Mustapha ANL/Phys, Argonne, Illinois
	A low beam-loss budget is an essential requirement for high-intensity machines and represents one of their major design challenges. In a high-intensity heavy-ion machine, losses are required to be below 1 W/m for hands-on-maintenance. The driver linac of the Rare Isotope Accelerator (RIA) is designed to accelerate beams of any ion to energies from 400 MeV per nucleon for uranium up to 950 MeV for protons with a beam power of up to 400 kW. The high intensity of the heaviest ions is achieved by acceleration of multiple-charge-state beams, which requires a careful beam dynamics optimization to minimize effective emittance growth and beam halo formation. For beam loss simulation purposes, large number of particles must be tracked through the linac. Therefore the computer code TRACK [P.N. Ostroumov and K.W. Shepard, PRST AB 11, 030101 (2001)] has been parallelized and calculations is being performed on the JAZZ cluster [] recently inaugurated at ANL. This paper discusses how this powerful tool is being used for simulations for the RIA project to help decide on the high-performance and cost-effective design of the driver linac. The Jazz Cluster, http://www.lcrc.anl.gov/jazz

WEPLT153	Multi-pass Beam-breakup: Theory and Calculation	simulation, recirculation, damping, injection	2197
	I. Bazarov Cornell University, Department of Physics, Ithaca, New York G. Hoffstaetter Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
	Multi-pass, multi-bunch beam-breakup (BBU) has been long known to be a potential limiting factor for the current in linac-based recirculating accelerators. New understanding of theoretical and computational aspects of the phenomenon are presented here. We also describe a detailed simulation study of BBU in the proposed 5 GeV Energy Recovery Linac light source at Cornell University which is presented in a separate contribution to this conference.

WEPLT156	Suppression of Microbunching Instability in the Linac Coherent Light Source	laser, electron, undulator, simulation	2206
	Z. Huang, P. Emma, C. Limborg-Deprey, G.V. Stupakov, J.J. Welch, J. Wu SLAC, Menlo Park, California M. Borland ANL/APS, Argonne, Illinois
	A microbunching instability driven by longitudinal space charge, coherent synchrotron radiation and linac wakefields is studied for the linac coherent light source (LCLS) accelerator system. Since the uncorrelated (local) energy spread of electron beams generated from a photocathode rf gun is very small, the microbunching gain may be large enough to significantly amplify shot noise fluctuations of the electron beam. The uncorrelated energy spread can be increased by an order of magnitude without degrading the free-electron laser performance to provide strong Landau damping against the instability. We study different damping options in the LCLS and discuss an effective laser heater to minimize the impacts of the instability on the quality of the electron beam.

WEPLT158	Direct Measurement of the Resistive Wakefield in Tapered Collimators	vacuum, impedance, electron, damping	2212
	P. Tenenbaum SLAC, Menlo Park, California D. Onoprienko Brunel University, Middlesex
	The transverse wakefield component arising from surface resistivity is expected to play a major role in the beam dynamics of future linear colliders. We report on a series of experiments in which the resistive wakefield was measured in a series of tapered collimators, using the Collimator Wakefield beam test facility at SLAC. In order to separate the contributions of geometric and resistive wakefields, two sets of collimators with identical geometries but different resistivities were measured. The results are in agreement with the theoretical prediction for the high-resistivity (titanium) collimators, but in the case of low-resistivity (copper) collimators the resistive deflections appear to be substantially larger than predicted.

WEPLT167	A Cure for Multipass Beam Breakup in Recirculating Linacs	feedback, dipole, recirculation, simulation	2218
	B.C. Yunn Jefferson Lab, Newport News, Virginia
	We investigate a method to control the multipass dipole beam breakup instability in a recirculating linac including energy recovery. Effectiveness of an external feedback system for such a goal is shown clearly in a simplified model. We also verify the theoretical result with a simulation study.

WEPLT172	Design & Handling of High Activity Collimators &Ring Components on the SNS	vacuum, target, shielding, extraction	2233
	G.R. Murdoch, D. Crisp, S. Henderson, M. Holding, K. Potter, T. Roseberry ORNL/SNS, Oak Ridge, Tennessee
	Design & Handling of High Activity Collimators on the SNSG Murdoch,S Henderson, K Potter,T Roseberry,Oak Ridge National Laboratory, USA,H Ludewig, N Simos, Brookhaven National Laboratory, USAJ Hirst, Rutherford Appleton Laboratory,UK, The Spallation Neutron Source accelerator systems will provide a 1GeV, 1.44MW proton beam to a liquid mercury target for neutron production. The expected highest doses to components are in the collimator regions. This paper presents the mechanical engineering design of a typical collimator highlighting the design features incorporated to assist with removal once it is activated. These features include shielding and lifting fixtures but more importantly a double contained flexible water system incorporating remote water couplings.Also presented is a mechanism that allows axial removal of vacuum bellows and its associated vacuum clamps.SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos and Oak Ridge.

THOACH02	Commissioning of the 500 MeV Injector for MAX-lab	gun, electron, storage-ring, injection	219
	S. Werin, Å. Andersson, M. Bergqvist, M. Brandin, M. Demirkan, M. Eriksson, L.-J. Lindgren, L. Malmgren, H. Tarawneh, E.J. Wallén MAX-lab, Lund B. Anderberg AMACC, Uppsala G. Georgsson Danfysik A/S, Jyllinge G. LeBlanc ASP, Melbourne
	A 500 MeV new injector system for the storage rings MAX I, II and III have been installed during the winter 2003-4 at MAX-lab. The system consists of two linacs at 125 MeV each, using SLED, and a recirculating system such that the electrons pass the linacs twice, thus reaching a final energy of 500 MeV. The system is injected by a thermionic RF-gun. The commissioning of the complete system will be performed in the spring 2004.
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THYCH01	Issues and Challenges for Short Pulse Radiation Production	electron, laser, photon, radiation	225
	P. Emma SLAC/ARDA, Menlo Park, California
	A new generation of light sources are being planned at many locations, pushing the frontiers of brightness, wavelength, and peak power well beyond existing 3rd generation sources. In addition to these large scale improvements there is great interest in extremely short duration pulses into the femtosecond and sub-femtosecond regime. Collective electron bunch instabilities at these scales are severe, especially in consideration of the high-brightness electron bunch requirements. Several new schemes propose very short radiation pulses generated with moderate electron bunch lengths. Such schemes include radiation pulse compression, differential bunch spoiling, staged high-gain harmonic generation, and selective pulse seeding schemes. We will describe a few of these ideas and address some of the electron bunch length limitations, highlighting recent measurements at the Sub-Picosecond Pulse Source (SPPS) at SLAC where <100-fs electron and x-ray pulses are now available.
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THZCH03	JACoW, a Collaboration Serving the Accelerator Community	site, feedback, cyclotron	249
	J. Poole, C. Petit-Jean-Genaz CERN, Geneva
	The Joint Accelerator Conferences Website started from an idea to publish the conference proceedings on the WWW and has grown to an international collaboration which does much more than just publish the proceedings and is currently supported by seven conference series. Through attendance at Steering Committee meetings and Team Meetings and through active participation in the work of the editorial teams of sister conferences, people with the responsibility for the production of the electronic versions of conference proceedings come together to learn from the experience of colleagues, and to develop common approaches to problems. The activities of the collaboration cover all aspects of electronic publication and have recently extended into conference scientific programme management. This paper reviews the history of the collaboration, describes some of the highlights in the activities during the life of the collaboration and presents the current status and future plans.
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THOALH01	Bunch Length Measurements at the SLS Linac using Electro-optical Techniques	laser, radiation, electron, radio-frequency	253
	A. Winter, M. Tonutti RWTH, Aachen S. Casalbuoni, P. Schmüser, S. Simrock, B. Steffen DESY, Hamburg T. Korhonen, T. Schilcher, V. Schlott, H. Sigg, D. Suetterlin PSI, Villigen
	The temporal profile of the electron bunches in the SLS Linac will be determined by means of electro-optical techniques. A mode locked Ti:Sa Laser with 15 fs pulse width is used for coincidence measurements between the laser pulse and the coherent transition radiation (CTR) generated by short electron bunches. Synchronization accuracy of 100 fs rms between the 3 GHz Linac RF and the 81 MHz repetition rate of the laser was achieved, which is important for the optimum time resolution of the applied electro-optical sampling technique. Likewise, a mode locked Nd:YAG laser with 400 ps long pulses will be used for electro-optical autocorrelation measurements between the CTR and the laser pulses. This alternative technique promises single shot capability and requires much relaxed synchronization stability between laser and electron beam.
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THOALH03	The Measurements of the Longitudinal Beam Profile on the Preinjector VEPP-5	electron, radiation, single-bunch, space-charge	259
	S. Gurov, P.A. Bak, P.V. Logatchev, V. Pavlov, E. Pyata BINP SB RAS, Novosibirsk D. Chernousov ICKC, Novosibirsk
	For effective work of preinjector VEPP-5 it is necessary 3 ns bunch with charge 1* 1010 electrons from termogun compress to bunch with 40 ps duration on the positron target. A new streak-camera with RF cavity on the main linac frequency is used. Streak-camera with circle scanning allows see 350 ps single light signal with sub-ps resolution. An additional slow scanning can obtain the trochoidal scanning. Thus one can see with picosecond resolution and with less then 1 psec synchronization the train of ten bunches which are spacing by 350psec. The results of worked streak-camera with RF-cavity for circle scanning are presented.
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THPKF002	Linac RF Control System for CANDLE. Design and Simulation	simulation, feedback, electron, resonance	2257
	A. Vardanyan, G. Amatuni CANDLE, Yerevan
	The design and constructional features of the control system for 500 MHz and 3 GHz RF system of CANDLE linac are presented. The linac includes an electron gun that is modulated by 500 MHz generator to produce 1 ns electron bunches, 500 MHz and 3 GHz bunchers, pre-accelerating cavity and the main accelerating section at 3 GHz. An important feature of the presented control system is a high level synchronization of amplitude-phase characteristics of the sub-systems that provide the required energy-space characteristics of the accelerated beam. This puts strict requirements on RF frequency, amplitude and phase stabilization. A digital feedback system has been adopted to provide flexibility in the control algorithms. The main feature is a 9 MHz sampling rate for the cavity signals and digital I/Q detection. The design was performed using the RF analyze tool, based on MATLAB SIMULINK, which allows the simulation and analyzes of the field regulation quality. The simulation results for CANDLE Linac RF system, based on the output parameters of electron beam are given.

THPKF008	Injection System for the Canadian Light Source	injection, storage-ring, booster, septum	2272
	R.M. Silzer, R. Berg, J.C. Bergstrom, L. Dallin, X. Shen, J.M. Vogt CLS, Saskatoon, Saskatchewan
	The full energy injection system for the Canadian Light Source is made up of a 250 MeV linac, a low energy transfer line, a 2.9 GeV booster synchrotron and a high energy transfer line. The system has routinely provided up to 25 mA peak current in a 132 ns pulse train to the CLS storage ring injection point since September 2003. By January, 2004, injection efficiencies up to 10% have been acheived and stored currents up to 25 mA were accumulated in less than 4 minutes. The injection timing system allows a variety of fill patterns. By July, 2004, injection rates of up to 2 mA per second should be possible providing a fill time of under one minute for a 100 mA stored beam.

THPKF012	Operation of the Swiss Light Source: Top-up for Highest Performance	injection, booster, feedback, beam-losses	2281
	A. Lüdeke PSI, Villigen
	The Swiss Light Source (SLS) is now in its third year of user operation. Right from the beginning Top-up has been the standard mode of operation. Operation at a fixed beam current makes many applications easier to implement and allows to push several systems to higher performance. It enabled us to reach an excellent orbit stability and reproducibility and it made our users less sensitive to shortened beam lifetimes. We succeeded to satisfy the high demands on the availability of the injector system and our flexible timing system allows for a parallel usage of the Linac for experiments during Top-up operation. The impact of Top-up operation on the overall performance of the SLS is documented in this paper.

THPKF034	Design of a Photoneutron Source based on a 5 MeV Electron Linac	target, electron, photon, simulation	2347
	L. Auditore, R.C. Barnà, D. De Pasquale, A. Trifirò, M. Trimarchi INFN & Messina University, S. Agata, Messina A. Italiano INFN - Gruppo Messina, S. Agata, Messina
	A photoneutron source, based on a 5 MeV electron linac was designed by means of the MCNP simulation code. Although higher electron energies are required to produce acceptable neutron fluxes, the availability of a 5 MeV electron linac developed at the Dipartimento di Fisica (Università di Messina) has suggested this project, in sight of a future development and testing of the studied neutron source. Be and BeD2 targets were considered, whose neutron production was studied optimizing two sequential steps: the bremsstrahlung production in a suitable e-gamma converter and the (gamma,n) production in an properly designed photoneutron target-reflector-moderator system. As a result of a comparative study of different materials performances, a 0.88 mm-thick W layer was chosen as e-gamma converter. A natural graphite reflector was designed, surrounding the target, enhancing the neutron flux of two order of magnitude. The final neutron flux, at 50 cm from the photoneutron target, thermalized by a 12.2 cm-thick PE layer, was estimated to be 8.48E+07 n/cm2/sec/mA with Be target and 1.23E+08 n/cm2/sec/mA with BeD2 target.

THPKF035	Design of the Super-SOR Light Source	synchrotron, injection, storage-ring, optics	2350
	N. Nakamura ISSP/SRL, Chiba
	The Super-SOR light source is a Japanese VUV and soft X-ray third-generation synchrotron radiation source, which is to be operated for nation-wide and world-wide users. The University of Tokyo has proposed to construct the facility in Kashiwa new campus and we have designed the light source intensively for more than two years. The light source consists of an electron storage ring, booster synchrotron and pre-injector linac. The 1.8-GeV storage ring has a circumference of about 280 m and 14 DBA cells with two 17-m and twelve 6.2-m long straight sections, which are used for twelve insertion devices and RF and injection systems. The booster synchrotron is compact, one third of the ring in circumference, and can achieve a low emittance of about 50 nmrad at 1.8 GeV. The 200-MeV linac is made up of S-band accelerating structures powered by two 50-MW klystrons and a SLED cavity and capable of changing the beam current widely in both single^- and multi-bunch operation modes. These accelerators are designed so as to fully meet requirements for top-up injection. We describe the design of the Super-SOR accelerators here. on behalf of the Super-SOR accelerator design group

THPKF040	Development of a Femtosecond Pulse Radiolysis for Reaction Analysis in Nano-space	laser, electron, ion, gun	2365
	Y. Yoshida, T. Kozawa, S. Tagawa, J. Yang ISIR, Osaka
	A new femtosecond pulseradiolysis system was developed in Osaka University for the study of radiation-induced ultrafast physical and chemical reactions in femtosecond time regions. In the pulseradiolysis system, a femtosecond electron beam produced by a photocathode RF gun is used as an irradiation source, while a mode-locked Ti:Sapphire femtosecond laser was used as a probe light source. A time jitter between the electron pulse and the femtosecond laser was compensated by a jitter compensation technique used a femtosecond streak camera. An oblique incidence of the probe light is considered in the system to reduce the degradation of velocity difference between the electron and the laser light in samples. A time resolution of <100 fs is expected in the pulse radiolysis system for the analysis of utrafast physical and chemical reactions in nano-space.

THPKF044	The Improvement of NSRRC Linac for Top-up Mode Operation	electron, storage-ring, power-supply, gun	2374
	J.-Y. Hwang, J. Chen, J.-P. Chiou, K.-T. Hsu, S.Y. Hsu, K.H. Hu, T.C. King, C.H. Kuo, K.-K. Lin, C.-J. Wang, Y.-T. Yang NSRRC, Hsinchu C.T. Pan NTHU, Hsinchu
	The performance of the 50 MeV linac at the National Synchrotron Radiation Research Center (NSRRC) was examined and has been improved recently. The major improved items were 1) adopting a command-charging scheme to replace the resonance charging for the linac modulator; and 2) gun electronics. As a result, the beam quality was improved in terms of its energy spectrum and stability. The correlation between the improvement of beam quality and component upgrading is analyzed. The influence of the beam quality improvement to the recently proposed top-up mode operation in 2005 will also be discussed in this report.

THPKF056	The MAX IV Facility	emittance, undulator, lattice, radiation	2392
	M. Eriksson, Å. Andersson, M. Bergqvist, M. Brandin, M. Demirkan, G. Georgsson, G. LeBlanc, L.-J. Lindgren, L. Malmgren, H. Tarawneh, E.J. Wallén, S. Werin MAX-lab, Lund B. Anderberg AMACC, Uppsala S. Biedron, S.V. Milton ANL, Argonne, Illinois
	The MAX IV facility is a planned successor of the existing MAX facility. The planned facilty is described below. It consists of two new synchrotron storage rings operated at different electron energies to cover a broad spectral region and one linac injector. The linac injector is also meant to be operated as a FEL electron source. The two rings have similar low emittance lattices and are placed on top of each other to save space. A third UV light source, MAX III, is planned to be transfered to the new facility.

THPKF060	Singapore Synchrotron Light Source– Helios 2 and Beyond	electron, synchrotron, plasma, radiation	2400
	H.O. Moser, B.D.F. Casse, E.P. Chew, M. Cholewa, C. Diao, S.X.D. Ding, M. Hua, J.R. Kong, Z. Li, S.bin. Mahmood, M.L. Ng, B.T. Saw, S.V.S. Vidyaraj, O. Wilhelmi, J.H.W. Wong, P. Yang, X.J. Yu SSLS, Singapore
	SSLS is operating a superconducting 700 MeV electron storage ring to produce synchrotron radiation over a useful spectral range from 10 keV to the far infrared for micro/nanofabrication, phase contrast imaging, surface and nano science with soft X-rays, and hard X-ray diffraction and absorption spectroscopy. An Infrared spectro/microscopy beamline is under construction. Latest results from all beamlines will be presented. SSLS is also working on a conceptual study of a Linac Undulator Light Installation (LIULI) that includes a superconducting miniundulator. Pursuing earlier work* a prototype built by ACCEL is being tested at SSLS and will later serve for FEL studies in cooperation with SSRF at Shanghai. * A. Geisler, A. Hobl, D. Krischel, H.O. Moser, R. Rossmanith, M. Schillo, First Field Measurements and Performance Tests of a Superconductive Undulator for Light Sources with a Period Length of 14 mm, ASC Conference, Houston, TX, August 2002

THPKF075	LUX - A Recirculating Linac-based Facility for Ultrafast X-ray Science	electron, laser, undulator, radiation	2439
	J.N. Corlett, W.A. Barletta, S. De Santis, L.R. Doolittle, W. Fawley, P.A. Heimann, S.R. Leone, D. Li, S.M. Lidia, G. Penn, A. Ratti, M. Reinsch, R.W. Schoenlein, J.W. Staples, G.D. Stover, S.P. Virostek, W. Wan, R. Wells, R.B. Wilcox, A. Wolski, J.S. Wurtele, A. Zholents LBNL, Berkeley, California
	We present design concepts for LUX - a proposed source of ultra-fast synchrotron radiation pulses based on a recirculating superconducting linac. The source produces high-flux VUV-x-ray pulses with duration of 100 fs or less at a 10 kHz repetition rate, optimized for the study of ultra-fast dynamics across many fields of science. Cascaded harmonic generation in free-electron lasers (FEL's) produces coherent radiation in the VUV-soft x-ray regime, and a specialized technique is used to compress spontaneous emission for ultra-short-pulse photon production in the 1 - 10 keV range. High-brightness electron bunches of 2-3 mm-mrad emittance at 1 nC charge in 30 ps duration are produced in an rf photocathode gun and compressed to 3 ps duration following an injector linac, and recirculated three times through a 1 GeV main linac. In each return path, harmonic cascades are inserted to produce seeded FEL radiation in selected photon energy ranges from approximately 20 eV with a single stage of harmonic generation, to 1 keV with a four-stage cascade. The lattice is designed to minimize emittance growth from effects such as coherent synchrotron radiation (CSR), and to propagate electron beams carrying nm-scale density modulation in the final stages of cascaded harmonic generation. Synchronization of tens of femtoseconds is achieved by use of an optical master oscillator distributing timing signals over actively stabilized fiber, and generation of rf signals from the optical master oscillator. We describe technical developments in key areas including injection from a high repetition rate rf photocathode gun, lattice design, UV and soft x-ray production by high-gain harmonic generation, a kicker design for rapid transfer of the electron beam between radiator beamlines, lasers systems concepts, and synchronization between experimental pump lasers and the x-ray pulse.

THPKF077	A Fiber Optic Synchronization System for LUX	laser, feedback, controls, undulator	2445
	R.B. Wilcox, L.R. Doolittle, J.W. Staples LBNL, Berkeley, California
	The proposed LUX femtotsecond light source will support pump-probe experiments that will need to synchronize laser light pulses with electron-beam-generated X-ray pulses to less than 50fs at the experimenter endstations. To synchronize multiple endstation lasers with the X-ray pulse, we are developing a fiber-distributed optical timing network. A high stability clock signal from a modelocked laser is distributed via fiber to RF cavities (controlling X-ray probe pulse timing) and modelocked lasers at endstations (controlling pump pulse timing). The superconducting cavities are actively locked to the optical clock phase. Most of the RF timing error is contained within a 10kHz bandwidth, so these errors and any others affecting X-ray pulse timing (such as RF gun phase) can be detected and transmitted digitally to correct laser timing at the endstations. The lasers? timing jitter is limited to low frequency, and thus they will follow the controls (clock plus error correction) without adding much wideband error. Time delay through the fibers will be stabilized by comparing a retroreflected pulse from the experimenter endstation end with a reference pulse from the sending end, and actively controlling the fiber length. Numerical simulations and initial synchronization experimental results will be presented.

THPKF084	Emerging Concepts, Technologies and Opportunities for Mezzo-scale Terahertz and Infrared Facilities	electron, radiation, synchrotron, laser	2454
	S. Chattopadhyay, S.T. Corneliussen, G.P. Williams Jefferson Lab, Newport News, Virginia
	Recent advances in particle beam, laser and radiofrequency technologies, combined with innovative concepts and techniques such as energy recovery, coherent synchrotron radiation-induced bunching, laser-particle beam scattering, ultrashort pulse slicing, cw high current and brightness phtoinjectors, ultrafast laser switching and compact engineered end products have opened up new opportunities and vistas in terahertz/infrared radiation sources not available before. Such sources would complement the high energy short wavelength x-ray sources in that they will allow us to probe collective processes and their ?function? in complex systems and materials, in a fashion complementary to probing structure via x-rays. We will outline and give examples of both the scientific reach of such radiation sources as well as examples of a few conceived facilities and techniques worldwide spanning a diversity of spectral, coherence, brightness and application ranges in the long wavelength. Such facilities fall in the category of mezzo-scale facilities, bracketed by table top lasers on one hand and large scale synchrotron radiation sources on the other and offer very unique and directed advances in a few key areas in life, materials, imaging, instrumentation and communication sciences.

THPLT027	Optical Transition Radiation Based Beam Diagnostics at the BESSY Synchrotron Radiation Source and FEL Accelerators	electron, laser, radiation, photon	2532
	T. Kamps, K. Holldack, P. Kuske BESSY GmbH, Berlin
	Optical Transition Radiation (OTR) based diagnostics tools are widely used in linear accelerators to measure beam parameters like transverse beam size and emittance. Design ideas for OTR stations in the linac section of the BESSY FEL facility are presented. Several key components will be tested in the transfer lines of the BESSY storage ring. Furthermore a novel type of OTR monitor is introduced which enables the measurement of the transverse overlap of seed laser and electron beam in the undulator sections of the linac based FEL facility. Here a special radiator screen will be used allowing simultaneous imaging of both beams in the same optical readout channel.

THPLT030	A Novel Device for Non-intersecting Bunch Shape Measurement at the High Current GSI-Linac	electron, background, space-charge, ion	2541
	P. Forck, C. Dorn, M.H. Herty, P. Strehl GSI, Darmstadt V. Peplov RAS/INR, Moscow S. Sharamentov ANL, Argonne, Illinois
	Due to the high current of heavy ions accelerated at the UNILAC at GSI, non-intersecting beam diagnostics are mandatory. For bunch length and bunch structure determination in the range of 0.3 to 5 ns a novel device has been realized. It uses the time spectrum of secondary electrons created by atomic collisions between beam ions and residual gas molecules. These electrons are accelerated by an electric field of 400 V/mm toward an electro-static energy analyzer. The analyzer is used to restrict of the effective source region. Then the electrons are deflected by an rf-resonator running in phase with the acceleration frequency (36 or 108 MHz) to transform the time spectrum into spatial separation. The detection is done with a multi-channel plate equipped with a phosphor screen and observed by a digital CCD camera. The achieved time resolution is at least 50 ps, corresponding to 2 degree of rf frequency. The general layout of the device and first results will be presented.

THPLT032	Computer Controlled Beam Diagnostics for the HICAT Facility	diagnostics, pick-up, ion, synchrotron	2547
	M. Schwickert, A. Peters GSI, Darmstadt
	A set of 93 diagnostic devices for beam diagnostics in the heavy ion cancer therapy facility (HICAT) at the university hospital in Heidelberg is currently under development at GSI. For the HICAT facility that is presently under construction, all beam diagnostic devices are fully computer controlled and allow an automated detection of all relevant beam parameters. The HICAT rasterscan method with active variation of intensity, energy and beam size requires the exact knowledge of the time resolved and spatial structure of the ion beam. An overview of the integrated devices is presented and the intensity measurement of both, the DC and AC beam in the different parts of the accelerator facility are reviewed. Additionally, the timing and control of the diagnostic devices are described.

THPLT050	End to End Simulations of the RX2 Beam Transport	target, simulation, focusing, cathode	2595
	N. Pichoff, J.-M. Lagniel CEA/DAM, Bruyères-le-Châtel
	RX2 is a project aiming to produce a high flux of X-rays for radiography purpose. We proposed an RF linac using a DC photo-injector producing 20 bunches with 100nC each at 352 MHz. The beam is then injected in 4 RF superconducting cavities and accelerated to 40 MeV. It is then focused on a target producing X-rays. Here is presented the design, the specificities, and the beam simulations from the cathode to the target by coupling 2 multiparticle codes : PARMELA and PARTRAN.

THPLT051	End to End Multiparticle Simulations of the AIRIX Linac	target, simulation, cathode, electron	2598
	N. Pichoff, A. Compant La Fontaine CEA/DAM, Bruyères-le-Châtel
	AIRIX is a working 3 kA, 20 MeV induction accelerator. It has been designed with an enveloppe code : ENV. A new set of multiparticle codes (PBGUNS, MAGIC, PARMELA and PARTRAN) has been used recently to simulate the beam transport with an higher accuracy especially taking into account the field non-linearities. A dedicated space-charge routine has been written. The calculation results have been compared to experimental measurements.

THPLT055	Longitudinal Phase Space Characterization of the CTF3 Beam with the RF Deflector	simulation, alignment, quadrupole, transverse-dynamics	2610
	D. Alesini, C. Biscari, A. Ghigo, F. Marcellini INFN/LNF, Frascati (Roma) R. Corsini CERN, Geneva
	The characterization of the longitudinal phase space of the CTF3 beam is an important item for tuning all machine parameters and increase the 30 GHz power production. By means of an RF deflector and a dispersive system the longitudinal phase space can be completely characterized. In this paper we present the simulation of the measurement and the mechanical layout of the full system.

THPLT057	An RF Deflector Design for 6d Phase Space Characterization of the Sparc Beam	simulation, emittance, quadrupole, dipole	2616
	C. Vaccarezza, D. Alesini INFN/LNF, Frascati (Roma) M. Amadei, P. Cascavola, A. Mostacci, L. Palumbo Rome University La Sapienza, Roma J. Rosenzweig UCLA, Los Angeles, California
	The characterization of the longitudinal and transverse phase space of the beam provided by the SPARC photoinjector is a crucial point to establish the performance quality of the photoinjector itself. By means of an RF deflector and a dispersive system, the six dimensional beam phase space can be analyzed. A five cell SW aluminum prototype of the SPARC RF deflector has been realized and tested. We report in this paper the design issues together with the RF measurement results. The simulation results of the 6D phase space reconstruction of the SPARC beam are also presented.

THPLT062	Alternating-phase-focused Linac for an Injector of Medical Synchrotrons	rfq, emittance, medical-accelerators, focusing	2631
	Y. Iwata, T. Fujisawa, T. Furukawa, T. Kanai, M. Kanazawa, N. Kanematsu, M. Komori, S. Minohara, T. Murakami, M. Muramatsu, K. Noda, M. Torikoshi, S. Yamada NIRS, Chiba-shi Y.F. Fujii, T. Mitsumoto, H. Tsutsui SHI, Tokyo T. Fujimoto, H.O. Ogawa, S. Shibuya AEC, Chiba V. Kapin MEPhI, Moscow
	Tumor therapy using Heavy Ion Medical Accelerator in Chiba (HIMAC) has been made over ten years at National Institute of Radiological Sciences (NIRS). Due to the successful clinical results, the project on developing compact medical accelerators for the tumor therapy has been started. To design these compact facilities, the size of a linac as well as the construction and operation costs is important. To satisfy these requirements, we propose Alternating-Phase-Focused (APF) linac using an Interdigital H-mode cavity. Since the axial and radial focusing of beam is made just with the acceleration rf field, no additional focusing elements is needed for the APF linac. This feature would make the costs lower than those of conventional linacs. The practical design of the APF linac will be presented.

THPLT063	Proposal of Carbon-beam Facility for Cancer Therapy in Japan	synchrotron, rfq, ion, extraction	2634
	K. Noda, T. Fujisawa, T. Furukawa, Y. Iwata, T. Kanai, M. Kanazawa, N. Kanematsu, A. Kitagawa, Y. Kobayashi, M. Komori, S. Minohara, T. Murakami, M. Muramatsu, S. Sato, Y. Sato, S. Shibuya, E. Takada, O. Takahashi, M. Torikoshi, E. Urakabe, S. Yamada, K. Yoshida NIRS, Chiba-shi
	Since 1994, the clinical trial at HIMAC has been successfully being progressed and more than 1,700 patients have treated with carbon ions. Owing to the good result of HIMAC, several medical groups in Japan have strongly required the carbon therapy facility. Based on the development of accelerator and the irradiation technologies for 10 years, therefore, we started to design a carbon therapy facility in Japan. The accelerator complex for the facility consists of two ECR ion sources with permanent magnets, an injector linac cascade (RFQ+IH) with the energy of 4 MeV/n, a synchrotron ring with the maximum energy of 400 MeV/n and beam delivery system for three treatment rooms. The R&D for the new facility has been already approved and will be started from April 2004. We will describe the conceptual design of the new facility.

THPLT074	The Beam Loss Monitor System of the J-parc LINAC, 3 GEV RCS and 50 GEV MR	beam-losses, extraction, radiation, injection	2667
	S. Lee, T. Toyama KEK, Ibaraki J. Kishiro JAERI/LINAC, Ibaraki-ken M. Tanaka JAERI, Ibaraki-ken
	The high intensity beam accelerator complex itself requires the significant progress of design study and hardware R&D. Operational beam intensity should be limited by the beam loss and activation level of the equipment. Once the beam loss exceeds a criterion at outer environment, beam intensity has to be decreased to prevent the further activation. In order to investigate loss mechanism and suppress the beam loss, a beam loss monitor system have been developed for the J-PARC linac, 3 GeV RCS and 50GeV MR. The system will be essential component for beam commissioning, tuning and machine protection in high intensity beam accelerators. The loss monitor system is composed of scintillator, argon-methane/3He gas filled proportional counter and air filled coaxial cable ionization chamber, which detect g-ray, neutron and charged particles induced by lost particle. It is necessary to measure wide dynamic range of loss intensity for various beam energies. To prevent the activation and heat load by intense beam loss, fast time response of loss signals is required. In this paper, construction and application of loss monitor system are described in detail. Preliminary result of demonstration in the KEK-PS and calibration with cobalt 60 g-ray radiation source are also discussed.

THPLT076	Compact X-band (11.424 Ghz) Linac for Cancer Therapy	electron, radiation, laser, simulation	2670
	N.H. Quyet, K. Dobashi, F. Ebina, M. El-Ashmawy, A. Fukasawa, H. Iijima, H. Ogino, M. Uesaka UTNL, Ibaraki
	Since most of medical linacs use S-band frequency, so far, such linacs cannot fit to modern advanced treatment techniques such as Tomotherapy and Stereotactic radiotherapy, which allows physicians to locate the tumor position during treatment time and enable for beam modification based on the real time analysis. Therefore, a new generation of electron linac with the compact size, higher power, higher gradient that can supply the advanced requirements of cancer treatment has been become necessary. X-band frequencies range is one of the suitable frequencies range for design such linacs. In this paper we will describe the possible design of a X-band (11.424 GHz) medical linac with side-coupled standing wave structure which understudying in NERL, The University of Tokyo. We aim to couple the therapy machine to the Compton scattering tunable monochromatic X-ray inspection device to realize the simultaneous inspection/therapy. Detailed design and numerical results are presented.

THPLT079	The Study of APF-IH Linac	ion, focusing, acceleration, proton	2679
	K. Yamamoto, T. Hattori, K. Yamamoto RLNR, Tokyo M. Okamura RIKEN, Saitama S. Yamada NIRS, Chiba-shi
	We have manufactured the IH linac with Alternating Phase Focus as the test machine of medical accelerator injection. It will accelerate C⁴⁺ ion up to 2MeV/u from 40 keV/u, the tank length is around 1.5m, operation frequency is 100MHz. Furthermore, We have succeeded the acceleration test using proton with simple acceleration system consist of P.I.G. ion source, bending magnets and focus lenses, less than 5m long. Otherwise, We have been making the program of beam dynamics with the results of the electro-magnetic simulation soft (Micro-Wave-Studio,OPERA-3D), it has the merit of easily to calculate the 3D- beam dynamics in the tank. We will report the some results of the test and the beam simulation and the comparisons.

THPLT083	Femto-second Bunch Length Measurement using the RF Deflector	electron, dipole, radiation, coupling	2691
	S. Kashiwagi, G. Isoyama, R. Kato, K.K. Kobayashi, Y. Matsui, A. Saeki, J. Yang ISIR, Osaka H. Hayano, M. Kuriki KEK, Ibaraki M. Kudo, M. Washio RISE, Tokyo
	The traveling wave type rf cavities operating in dipole mode (TM110-like) is being developed for a measurement of femto-second electron bunch. The femto-second electron bunch is used the pulse radiolysis experiments for the studies on radiation physics and chemistry with femto-second time resolution. The resonant frequency is tuned to the designing value 2856 MHz, which is accelerating frequency of a photo-injector linac at ISIR Osaka University. Further, we are planning to apply the design of the traveling wave rf deflector to a X-band crab cavities for the Global Linear Collider (GLC) project. In this conference, we will report the design of the traveling wave rf deflector and the result of cold test.

THPLT124	Simulation Technique for Study of Transient Self-consistent Beam Dynamics in RF Linacs	simulation, beam-loading, acceleration, impedance	2762
	V.V. Mytrochenko, A. Opanasenko NSC/KIPT, Kharkov
	The report describes a simulation technique for study of unsteady self-consistent dynamics of charged particles in resonant linacs. The technique allows simulating the linacs that consist of resonant cavities and traveling wave sections. The proposed approach is based on unsteady theories of excitation of resonant cavities and waveguides by a beam of charged particles and RF feeders. The theory of waveguide excitation is generalized to the case of spatially inhomogeneous traveling wave structures. The system of self-consistent differential equations for fields and motion of particles is integrated over time and space. The SUPERFISH code is used to evaluate characteristics of the axially symmetrical cavities and traveling wave sections. The PARMELA code is applied to simulate motion of the particles at each time step of the integration. In such a way the fields and beam characteristics in the axially symmetrical accelerating structures can be obtained for transient and steady state operation. Description of the algorithm and results of its validation are presented.

THPLT127	Beam Diagnostics Systems for the Diamond Synchrotron Light Source	electron, booster, storage-ring, synchrotron	2765
	G. Rehm, A.F.D. Morgan, C. Thomas Diamond, Oxfordshire
	We present an overview of the diagnostics systems that will be implemented at the Diamond synchrotron light source. The aim of this paper is to give a complete picture of the systems to measure the quality of the electron beam from the injector through to the storage ring. We will show how we intend to measure the dimensions, the position and the time structure of the electron bunches. In addition, the instrumentation to measure the charge, the current and the emittance of the electron beam will be described. Finally, systems to provide accurate measurement of electron losses and the injection efficiency will be detailed.

THPLT133	Simulation of RF Control of a Superconducting Linac for Relativistic Particles	simulation, feedback, beam-loading, proton	2774
	M. Huening, P. Bauer, G.W. Foster Fermilab, Batavia, Illinois
	We present a code to simulate the rf field and field control in a superconducting linac for relativistic heavy particles. In such a linac the field stability is strongly influenced by the longitudinal beam dynamics. So the code has to simulate both the field and the beam dynamics with the resulting varying beam loading. Other effects included in the simulation are Microphonics and Lorentz force. The code can simulate both single cavity and vector sum control.

THPLT147	Beam Halo Monitoring on the CLIC Test Facility 3	electron, photon, monitoring, radiation	2801
	T. Lefevre NU, Evanston H.-H. Braun, E. Bravin, R. Corsini, A.-L. Perrot, D. Schulte CERN, Geneva
	In high intensity accelerators, the knowledge of the beam halo distribution and its generation mechanisms are important issues. In order to study these phenomena, dedicated beam diagnostics must be foreseen. In circular machines, beam halo was monitored by using scrapers and beam loss detectors. In the framework of the CLIC project, beam halo monitoring is currently under development. The proposed device is based on an imaging system and a masking technique, which suppresses the core of the beam to allow direct observation of the beam halo. A first test was performed on the CLIC test facility 3 in 2003. We discuss the performances and the limitations of this technique pointing out our plans for future developments.

THPLT148	Beam Loss Monitoring on the CLIC Test Facility 3	beam-losses, simulation, monitoring, electron	2804
	T. Lefevre, M. Velasco, M. Wood NU, Evanston H.-H. Braun, R. Corsini, M. Gasior CERN, Geneva
	The CLIC test facility 3 (CTF3) provides a 3.5A, 1.5s electron beam pulse of 150MeV at the end of the linac. The average beam power is 4 kW. Beam loss will be monitored all along the linac in order to keep the radiation level as low as possible. The heavy beam loading of the linac can lead to time transients of beam position and size along the pulse. To compensate these transients effectively a beam loss monitor (BLM) technology has to be chosen with a time response faster than a few nanoseconds. In this context, two different tests have been performed in 2003 on the already existing part of the CTF3 accelerator. Several detectors based on different technologies were first tested in parallel to determine which one was the most appropriate. A second test, in which the beam was intentionally lost in well defined conditions, was then made with the aim of comparing the measurements with simulation results. We present here the results of these tests and our conclusion for the new system to be developed.

THPLT157	Beam-based Feedback for the NLC Linac	feedback, emittance, simulation, ground-motion	2828
	L. Hendrickson, N. Phinney, A. Seryi, P. Tenenbaum, M. Woodley SLAC, Menlo Park, California
	The NLC linac train-by-train feedback system is designed to stabilize the beam trajectory, but is also a valuable element in the strategy for emittance preservation. New simulations employ improved strategies [], allowing beam steering to be performed significantly less often than without the feedback system. Additional simulations indicate that the linac feedback can contribute towards successful operation at noisier sites. Beam-based Feedback Simulations for the NLC Linac, L. Hendrickson et al., LINAC, Monterey, California (2000)

THPLT166	Development of Injection and Optics Control Applications for the SNS Accumulator Ring	injection, optics, quadrupole, sextupole	2849
	S.M. Cousineau, C. Chu, J. Galambos, S. Henderson, T. Pelaia, M. Plum ORNL/SNS, Oak Ridge, Tennessee A.L. Leahman WSSU, Winston-Salem, North Carolina
	A large suite of physics software applications is being developed to facilitate beam measurement and control in the SNS accumulator ring. Two such applications are an injection control and measurement application, and a ring optics control application. The injection application will handle measurement and control of the linac beam position and angle at the stripper foil, and will be used to measure the twiss parameters of the linac beam at the foil. The optics control application will provide knobs for machine working point, chromaticity, arc phase advance, and harmonic correction. Both applications are written within the standard in-house XAL framework. Presented here are first versions of the applications, along with plans for future development and testing.

THPLT168	XAL - The SNS Application Programming Infrastructure	klystron, background, quadrupole, monitoring	2855
	J. Galambos, C. Chu, S.M. Cousineau, T. Pelaia, A. Shishlo ORNL/SNS, Oak Ridge, Tennessee C. Allen, C. McChesney LANL/LANSCE, Los Alamos, New Mexico W.-D. Klotz ESRF, Grenoble I. Kriznar, A. Zupanc Cosylab, Ljubljana
	A Java programming infrastructure for high level applications has been developed and is being used for the Spallation Neutron Source (SNS). The framework provides a hierarchal view of the accelerator and hides much of the underlying control system details. The hierarchy is database configured, facilitating sharing of applications across different beamlines, shielding the programmer from detailed knowledge of signal names, and allowing wholesale updating of applications. An important aspect of the framework is an online model, which can be run for design values, live machine values or user selected tuning values. Sample applications will be shown.

THPLT181	A Tomographic Technique for Magnetized Beam Matching	electron, gun, heavy-ion, quadrupole	2876
	C. Montag, I. Ben-Zvi, J. Kewisch BNL, Upton, Long Island, New York
	To maintain low electron beam temperatures in the proposed RHIC electron cooler, careful matching of the magnetized beam from the source to the cooler solenoid is mandatory. We propose a tomographic technique to diagnose matching conditions. First simulation results will be presented.