LINAC 2004 - List of Keywords

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

laser

Paper	Title	Other Keywords	Page
MO101	Advanced Analysis in Nanospace: Research with the XFEL	electron, free-electron-laser, radiation	1
	H. Dosch MPI, Stuttgart
	Little happens in industrialised countries without the use of high-tech materials which are the building blocks of all modern technologies ranging from information, communication, health, energy and environment to transport. In the last decades the development of novel materials has progressed at a breathtaking rate. This has become possible through our microscopic insight into the atomistic structure of condensed matter which finally enabled us to assemble new material systems atom-by-atom. These days, we are facing a revolution in the investigation of nanospace: Through new concepts in accelerator physics, electrons can be forced to emit short-pulsed x-ray laser radiation. Such a futuristic European x-ray free electron laser (XFEL) laboratory is currently being constructed and will allow mankind to finally get holographic snapshots of the motion of atoms and electrons in materials. Ultimate insights into matter, as the realtime-observation of the formation and the breaking of molecular bonds, sound like science fiction, but could become reality in less than a decade, if Europe embarks today into this bold adventure which will lead us into unexplored dimensions of nanospace.

MO202	High-Intensity, High Charge-State Heavy Ion Sources	ion, electron, ion-source, plasma	8
	J. Alessi BNL, Upton, Long Island, New York
	There are many accelerator applications for high intensity heavy ion sources, with recent needs including dc beams for RIA, and pulsed beams for injection into synchrotrons such as RHIC and LHC. The present status of sources producing high currents of high charge state heavy ions will be reviewed. These sources include ECR, EBIS, and Laser ion sources. The benefits and limitations for these type sources will be described, for both dc and pulsed applications. Possible future improvements in these type sources will also be discussed.
	Transparencies

MOP25	The LEBRA 125 MeV Electron Linac for FEL And PXR Generation	electron, linac, klystron, undulator	90
	K. Hayakawa, Y. Hayakawa, K. Ishiwata, K. Kanno, K. Nakao, T. Sakai, I. Sato, T. Tanaka LEBRA, Funabashi K. Yokoyama KEK, Ibaraki
	A 125 MeV electron linac has been constructed at Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University for Free Electron Laser (FEL) and Parametric X-ray (PXR) generation. Two klystrons feed rf power of approximately 20 MW peak and 20 μsec pulse duration each to an injector and three 4 m accelerating structures. Phase of the rf fed to each component is controlled independently. Two accelerating structures connected with the second klystron and a ninety degrees bending system as a momentum analyzer constitute a magnetic bunching system. Electron bunches of 3 to 4 psec width formed at the injector are compressed to within 1 psec during passing through the magnetic bunching system. Peak current of the electron beam injected to the FEL system installed downstream of the momentum analyzer is expected to be about 50 A. FEL lasing has been achieved at the wavelength range from 1 to 6 mm. Estimated peak power of the extracted FEL light pulse is about 2 MW. Applied researches using the FEL started last autumn. Preliminary experiment for the PXR generation has been continued.

MOP26	ERLP Gun Commissioning Beamline Design	electron, diagnostics, gun, emittance	93
	D.J. Holder, C.K.M. Gerth, F.E. Hannon CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire R.J. Smith CLRC, Daresbury, Warrington, Cheshire
	The 4GLS project is a novel next-generation solution for a UK national light source. It is based on an energy recovery linac (ERL) operating at high average beam currents up to 100 mA and with compression schemes producing pulses in the 10 - 100 fs range. This challenging accelerator technology, new to Europe, necessitates a significant R&D programme and a major part of this is a low-energy prototype, the ERLP, which is currently under construction at Daresbury Laboratory, in the north-west of England. The first components of ERLP to be built will be the DC photocathode gun and low-energy beam transport and diagnostics. The gun will initially be operated with a diagnostic beamline in order to measure the properties of the high-brightness beams generated as fully as possible. This will allow comparison of its performance with the results of multi-particle tracking codes, prior to its integration into the ERLP machine. The diagnostic beamline will include diagnostics for measuring the transverse and longitudinal properties of the electron beam. This paper will describe the design of this diagnostic beamline and demonstrate through simulation, the expected characteristics and performance achievable from this system.

MOP46	Experimental Investigation of the Longitudinal Beam Dynamics in a Photo-Injector using a Two-Macroparticle Bunch	electron, simulation, booster, bunching	147
	R. Tikhoplav, A.C. Melissinos Rochester University, Rochester, New York N. Barov, D. Mihalcea Northern Illinois University, DeKalb, Illinois P. Piot FNAL, Batavia, Illinois
	We have developed a two-macroparticle bunch to explore the longitudinal beam dynamics through various component of the Fermilab/NICADD photoinjector laboratory. Such a two-macroparticle bunch is generated by splitting the photocathode drive laser impinging the photocathode. The presented method allows the exploration of rf-induced compression in the 1+1/2 cell rf-gun and in the 9-cell TESLA cavity. It also allows a direct measurement of the magnetic chicane bunch compressor parameters such as its momentum compaction. The measurements are compared with analytical and numerical models. Finally we present possible extension of the technique to investigate the transverse beam dynamics.

MOP48	Gamma and X-rays Production for Experiments at ELSA Facility	electron, emittance, target, linac	153
	J. Lemaire CEA/DAM, Bruyères-le-Châtel
	The ELSA facility is a high brightness 18 MeV electron source dedicated to electron radiation, gamma-rays and picosecond hard and soft X-rays. It consists of a 144 MHz RF photoinjector producing short bunches which are further accelerated to a final energy varying from 2 to 18 MeV thanks to three 433 MHz RF cavities. Former beam compression design used a half turn magnet compressor system. It has been recently replaced by a double alpha magnet compressor. Electron beams are now delivered to a new experimental room. We present the new panel of interests offered by this facility in term of gamma-ray and X-ray production.

MOP75	Hminus Distribution in the HERA RF-Volume Source	electron, plasma, acceleration, extraction	198
	J. Peters DESY, Hamburg
	The HERA RF-Volume Source is the only source available that delivers routinely an Hminus current of 40 mA without Cs. The production mechanism for Hminus ions in this type of source is still under discussion. Laser photodetachment measurements have been started at DESY in order to measure the Hminus distribution in the source. The measurements have also been done under extraction conditions at high voltage. The results of the measurements with and without extraction are a basis for the development of a theory for the transition between plasma and vacuum (sheath), a cornerstone for beam transport programs. Knowledge of the H^- distribution and where they are produced makes further source improvements possible.

MOP80	Development of Adaptive Feedback Control System of Both Spatial and Temporal Beam Shaping for UV-Laser Light Source for RF Gun	electron, gun, emittance, cathode	207
	H. Tomizawa, T. Asaka, H. Dewa, H. Hanaki, T. Kobayashi, A. Mizuno, S. Suzuki, T. Taniuchi, K. Yanagida JASRI-SPring-8, Hyogo F. Matsui FKLAB, Fukui City
	The ideal spatial and temporal profiles of a shot-by-shot single laser pulse are essential to suppress the emittance growth of the electron beam from a photo-cathode rf gun. We have been developing highly qualified UV-laser pulse as a light source of the rf gun for an injector candidate of future light sources. The gun cavity is a single-cell pillbox, and the copper inner wall is used as a photo cathode. The electron beam was accelerated up to 4.1 MeV at the maximum electric field on the cathode surface of 175 MV/m. For emittance compensation, two solenoid coils were used. As the first test run, with a microlens array as a simple spatial shaper, we obtained a minimum emittance value of 2 π·mm·mrad with a beam energy of 3.1 MeV, holding its charge to 0.1 nC/bunch. In the next test run, we prepared a deformable mirror for spatial shaping, and a spatial light modulator based on fused-silica plates for temporal shaping. We applied the both adaptive optics to automatically shape the both spatial and temporal UV-laser profiles with a feedback routine at the same time. We report herein the principle and developing process of our laser beam quality control system.

TU102	Survey of Advanced Acceleration Techniques	electron, plasma, acceleration, undulator	242
	C.J. Joshi UCLA, Los Angeles, California
	In this talk I will review the recent progress on the production, manipulation, transport, acceleration and focusing of relativistic electron beams using advanced techniques. In particular, I will report recent progress on cathode-less electron injectors, IFEL bunchers and accelerators, plasma accelerating and transport structures, and electron and positron beam focusing using plasmas. The plasma structures for acceleration can be excited either by laser beams or charged-particle beams. The acceleration gradients in either case can be enormous. For unmatched beams the betatron radiation loss, as the beam oscillates transversely in the high gradient accelerating structure, can generate a high brightness x-ray beam. These x-rays can, in turn, be used to generate positrons. Work done by different groups around the world will be reviewed.
	Transparencies

TU302	Future Developments in Electron Linac Diagnostics	linac, emittance, instrumentation, electron	280
	M.C. Ross SLAC/NLC, Menlo Park, California
	The next generation of electron linacs will fill two different roles: ultra-low emittance, very high power accelerators for linear colliders and ultra-short bunch, high stability accelerators for SASE X-ray production. In either case, precision control based on non-invasive, reliable, beam instrumentation will be required. For the linear collider, low emittance transport is an important concern for both warm and superconducting linacs. Instrumentation will be used to control and diagnostics will be used to validate emittance preserving strategies, such as beam based alignment and dispersion - free steering. Tests at the KEK ATF and the SLAC FFTB have demonstrated the required performance for beam position and beam size monitors. Linacs intended for FEL's will require precision bunch length diagnostics because of expected non-linear micro-bunching processes. A wide variety of devices are now in development at FEL prototypes, including TTF2 at DESY and SPPS at SLAC. We present a review of the new diagnostic systems.
	Transparencies

TUP11	High current RFQ using laser ion source	rfq, plasma, ion, ion-source	315
	M. Okamura, R.A. Jameson, J. Takano, K. Yamamoto RIKEN, Saitama R. Becker, A. Schempp IAP, Frankfurt-am-Main T. Fujimoto AEC, Chiba T. Hattori, N. Hayashizaki TIT, Tokyo Y. Iwata, S. Shibuya NIRS, Chiba-shi H. Kashiwagi JAERI/ARTC, Gunma-ken
	A new RFQ was fabricated for very high current heavy ions. The designed target current is 100 mA with cabon 4⁺ beam. Acceleration test result will be reported at the conference.

TUP44	Linac Upgrades for FERMI@ELETTRA	linac, gun, klystron, injection	366
	G. D'Auria, R.J. Bakker, P. Craievich, G. De Ninno, S.D. Di Mitri, M. Ferianis, P.G. Pangon, R.L. Rumiz, T.L. Tosi, D. Zangrando Sincrotrone Trieste S.C.p.A., Basovizza, Trieste C. Bocchetta, M. Danailov, B. Diviacco, V. Verzilov ELETTRA, Basovizza, Trieste
	To fulfill the stringent requirements expected from the FERMI project, the existing Linac needs some modifications in the layout and an upgrading of the present plants. Moreover, for the next two years, until the new injection system (now under construction) is fully commissioned, the Linac has to be kept in operation as injector for the ELETTRA Storage Ring. Therefore most of the planned activities have to be carried out without interfering with the normal operation of the machine. Details on the new Linac layout and related activities are discussed.

TUP47	The Photo Injector Test Facility at DESY Zeuthen: Results of the First Phase	emittance, gun, cathode, electron	375
	A. Oppelt, K. Abrahamyan, I. Bohnet, J. Bähr, U. Gensch, H.-J. Grabosch, J.H. Han, M. Krasilnikov, D. Lipka, V. Miltchev, B. Petrosyan, L. Staykov, F. Stephan DESY Zeuthen, Zeuthen W. Ackermann, W.F.O. Müller, S. Setzer, T. Weiland TU Darmstadt, Darmstadt J.-P. Carneiro, K. Flöttmann, S. Schreiber DESY, Hamburg E. Jaeschke, D. Krämer, D. Richter, M. von Hartrott BESSY GmbH, Berlin P. Michelato, C. Pagani, D. Sertore INFN/LASA, Segrate (MI) J. Rossbach Uni HH, Hamburg W. Sandner, I. Will MBI, Berlin I. Tsakov INRNE, Sofia
	The photo injector test facility at DESY Zeuthen successfully concluded it's first phase of operation in November 2003 (PITZ1). After a complete characterization of the injector, the gun has been delivered to Hamburg and has already been taken into operation on the VUV-FEL. The measurement program for the year 2003 included RF commissioning, emittance studies, momentum and bunch length measurements, and studies of the influence of the drive laser parameters. We provide an overview on the latest achievements in all of these topics.
	Transparencies

TUP48	Progress Report on the Flat Beam Experiment at the Fermilab/Nicadd Photoinjector Laboratory	emittance, simulation, cathode, quadrupole	378
	Y.-E. Sun, K.-J. Kim Chicago University, Chicago, Illinois N. Barov Northern Illinois University, DeKalb, Illinois K. Desler DESY, Hamburg H. Edwards, P. Piot, J. Santucci, J. Wennerberg FNAL, Batavia, Illinois M. Huening Fermilab, Batavia, Illinois S. Lidia LBNL/AFR, Berkeley, California R. Tikhoplav Rochester University, Rochester, New York
	We report on our present progress toward the investigation on the generation of flat beam from an incoming angular-momentum-dominated beam, along with the associated diagnostics development. We focus on the evolution of the four-dimensional beam matrix upstream and downstream of the round-to-flat beam transformer. Finally we compare our latest experimental results with numerical and analytical models.

TUP53	Temporal Profile of the LCLS Photocathode Ultraviolet Drive Laser Tolerated by the Microbunching Instability	undulator, simulation, damping, emittance	390
	J. Wu, Z. Huang SLAC, Menlo Park, California M. Borland ANL, Argonne, Illinois P. Emma SLAC/ARDA, Menlo Park, California C. Limborg SLAC/SSRL, Menlo Park, California
	The high quality LCLS electron beam generated in the photoinjector is subject to all possible instabilities in the downstream acceleration and compression. The instability can be initiated by any possible density modulation of the electron beam when it is generated at the photocathode. In this note, we prescribe the tolerance on the initial electron beam density modulation possibly introduced by the ultraviolet (uv) laser at the cathode. Our study shows that the initial rms density modulation of the electron beam at the photocathode shall be less than 5 % to ensure the FEL lasing and saturation.

TUP59	Extraction of High Charge Electron Bunch from the ELSA RF Injector - Comparison Between Simulation and Experiment	simulation, space-charge, gun, electron	402
	J. Lemaire, P. Balleyguier, A. Binet, J.M. Lagniel, V. Le Flanchec, N. Pichoff CEA/DAM, Bruyères-le-Châtel R. Bailly-Salins, M. Millerioux, Chr. Quine CEA/DIF/DPTA/SP2A, Bruyeres-le-Chatel
	A new scheme based on a photoinjector and a RF linear accelerator operating at 352 MHz has been recently proposed as a versatile radiographic facility. Beam pulses of 60 ns duration contain 20 succesive electron bunches which will be extracted at 2.5 MeV from a photoinjector then accelerated through the next structure to the final energy of 51 MeV. Bunches carrying 100 nC are required for this purpose. As a first demonstrating step, 50 nC electron bunches have been produced and accelerated to 2.5 MeV with the 144 MHz ELSA photoinjector at Bruyères le Chatel. For this experiment, we compare the results and the numerical simulations made with PARMELA, MAGIC and MAFIA codes.

TUP78	Diagnostics for the Low Level RF Control for the European XFEL	diagnostics, monitoring, feedback, radiation	453
	T. Jezynski, P. Pucyk WUT, Warsaw S. Simrock DESY, Hamburg
	One of the most important aims of the diagnostic system is to provide high reliability. This article describes the concept and the proposal for diagnostic system for Low Level Radio Frequency system for EU-XFEL. It enables immediate location of faults and understanding of their causes, tests the functionality of LLRF system, tests each the electronic board and connections. Diagnostic system tests different system components and compares results from these tests with e.g. from power supplies monitors. Hardware, software and database aspect of diagnostic system is presented. The main part of this paper is devoted to hardware and software specification.

WE103	State of the Art in RF Control	feedback, linac, diagnostics, resonance	523
	S. Simrock DESY, Hamburg
	Nowadays the designer of a new rf control system has access to a wealth of powerful digital, analog, and rf circuitry. The requirements for the rf control system have changed from only controlling the amplitude and phase of the accelerating field to the required degree to stability. Additional tasks include exception handling and extensive build-in diagnostics while pursuing issues related to reliability, operability, and maintainability. Also operation close to the performance limit must be supported while maximizing the availability of the accelerator. With many accelerator projects in planning or under construction several state-of-the art rf control designs have evolved. This paper will present an overview of this new technology and discuss its performance.
	Transparencies

THP24	Highly Polarized Electrons from GaAs-GaAsP and InGaAs-AlGaAs Strained Layer Superlattice Photocathodes	cathode, electron, photon, polarization	648
	T. Nakanishi, F. Furuta, M. Kuwahara, K. Naniwa, T. Nishitani, S. Okumi, N. Yamamoto, K. Yasui DOP Nagoya, Nagoya H. Horinaka, T. Matsuyama OPU, Osaka H. Kobayakawa, Y. Takashima, Y. Takeda, O. Watanabe DOE Nagoya, Nagoya-City
	GaAs-GaAsP strained layer superlattice photocathode has been developed for highly polarized electron beams. This cathode achieved a maximum polarization of 92% with a quantum efficiency of 0.5%. Criteria for achieving the highest polarization together with high quantum efficiency using superlattice photocathodes are discussed based on experimental spin-resolved quantum efficiency spectra of GaAs-AlGaAs, InGaAs-AlGaAs and GaAs-GaAsP superlattice structures.

THP49	The RF-Station Interlock for the European X-ray laser	klystron, diagnostics, power-supply, monitoring	718
	T. Grevsmühl, S. Choroba, Ph. Duval, O. Hensler, J. Kahl, F.-R. Kaiser, A. Kretzschmann, K. Rehlich, U. Schwendicke, S. Simrock, S. Weisse DESY, Hamburg H. Leich, RW. Wenndorff DESY Zeuthen, Zeuthen
	The RF-station interlock for the European X-ray laser will be based on a 19"- 3U crate incorporating a controller with the 32-bit RISC NIOS-processor (ALTERA). The main task of the interlock system is to prevent any damage from the components of the RF station and connected cavities. The interlock system must also guarantee a maximum time of operation of the RF stations which implies the implementation of self diagnostics and repair strategies on a module basis. Additional tasks are: collection and temporary storage of status information of the individual channels of the interlock system, transfer of this information to the control system, slow control functions (e.g. HV setting and monitoring) and control of inputs and outputs from and to other subsystems. In this paper we present the implementation using an ALTERA-FPGA running a 32-bit RISC NIOS-processor. Connection to the accelerator main control is provided by Ethernet using BSD-style socket routines based on ALTERA's plugs-library. The layout of the system is presented and first hardware components are shown.

THP74	Laser Produced Ions as an Injection Beam for Cancer Therapy Facility	ion, target, proton, plasma	782
	A. Noda, M. Hashida, Y. Iwashita, S. Nakamura, S. Sakabe, S. Shimizu, T. Shirai, H. Tongu Kyoto ICR, Kyoto H. Daido JAERI APRC, Ibaraki-ken A. Fukumi, Z. Li, K. Matsukado NIRS, Chiba-shi T. Hosokai, H. Iijima, K. Kinoshita, M. Uesaka, T. Watanabe, K. Yoshii UTNL, Ibaraki T. Takeuchi DOP Nagoya, Nagoya
	Ion production from a solid target by a high-power short pulse laser has been investigated to replace the injector linac of the synchrotron dedicated for cancer therapy. As the high power laser, the laser with the peak power of 100 TW and minimum pulse duration of 20 fs which has been developed at JAERI Kansai Research Establishment, is assumed. Laser produced ions with 100% energy spread is energy selected within ±5% and then phase rotated with use of the RF electric field synchronized to the pulse laser, which further reduces the energy spread to ±1%. The scheme of the phase rotation is presented together with the experimental results of laser production from the thin foil target.

FR103	Status of the SNS Linac: An Overview	linac, target, proton, rfq	837
	N. Holtkamp ORNL, Oak Ridge
	The Spallation Neutron Source SNS is a second generation pulsed neutron source and under construction at Oak Ridge National Laboratory. The SNS is funded by the U.S. Department of Energy?s Office of Basic energy Sciences and is dedicated to the study of the structure and dynamics of materials by neutron scattering. A collaboration composed of six national laboratories (ANL, BNL, TJNAF, LANL, LBNL, ORNL) is responsible for the design and construction of the various subsystems. With the official start in October 1998, the operation of the facility will begin in 2006 and deliver a 1.0 GeV, 1.4 MW proton beam with a pulse length of approximately 700 nanoseconds on a liquid mercury target. The multi-lab collaboration allowed access to a large variety of expertise in order to enhance the delivered beam power by almost an order of magnitude compared to existing neutron facilities. The SNS linac consists of a combination of room temperature and superconducting structures and will be the first pulsed high power sc linac in the world. The challenges and the achievements will be described in the paper. 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.
	Transparencies