APAC 2007 - List of Keywords (emittance)

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

emittance

Paper	Title	Other Keywords	Page
MOYMA01	Overview of Energy-Recovery Linacs	electron, linac, radiation, laser	11
	R. Hajima JAEA/ERL, Ibaraki
	An energy-recovery linac (ERL) is capable of generating an electron beam of high-brightness and high average current. It is, thus, a promising device for future light sources such as next-generation X-ray sources and high-power FELs, and several projects are under way in the world. In this talk, we overview the current status of these projects. Recent studies on beam dynamics issues and development of key components for the ERLs are also presented.
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TUC3MA01	ILC DR Alternative Lattice Design	lattice, damping, dynamic-aperture, wiggler	94
	Y. Sun, Z. Y. Guo PKU/IHIP, Beijing J. Gao IHEP Beijing, Beijing
	The International Linear Collider (ILC) which is based on super-conducting RF acceleration technology requires the damping rings to provide beams with extremely small equilibrium emittances, and large acceptance to ensure good injection efficiency for high emittance, high energy spread beam from the positron source. In order to reduce the cost for ILC damping rings, an alternative lattice which is different from the baseline configuration design has been designed with modified FODO arc cells，and the total quadrupole number has been reduced by half. At the same time, to decrease the total cost involved in constructing access shafts needed to supply power, cryogenics etc. for the wigglers and other systems, the number of wiggler sections is decreased from 8 to 4, and further to 2. This new lattice has been optimised to have a good dynamic aperture. This alternative ILC damping ring lattice design will reduce the cost largely compared with the baseline design.
	Slides

TUPMA023	Project of 2 GeV Synchroton Light Source for the Republic of Kazakhstan	lattice, synchrotron, radiation, dipole	136
	E. Antokhin, G. Kulipanov, N. A. Mezentsev, V. E. Panchenko, A. V. Philipchenko, A. V. Utkin, K. Zolotarev BINP SB RAS, Novosibirsk K. K. Kadyrzhanov, S. N. Lyssukhin INP NNC RK, Almaty
	Applications of synchrotron radiation (SR) are very popular for last time in many research fields. Thus a developing of compact source for generation of hard X-ray synchrotron radiation is very actual task. The goal of this work is a developing project of SR source for Republic of Kazakhstan. This storage ring mainly dedicated for performing the high sensitive X-ray fluorescence analysis of different natural samples to be used for ore exploration, ore processing and metallurgy . But implementations of other popular techniques applied for research and education with using synchrotron radiation (XAFS, XRD, etc) are also possible. This report includes a detailed description of main parameters and magnetic structure of designed storage ring as well as preliminary design of injector system.

TUPMA036	Comparative Studies of Electron Sources for a Free Electron Laser at PSI	electron, gun, cathode, space-charge	157
	M. Dehler, A. Anghel PSI, Villigen
	Within the low emittance gun project LEG, the Paul Scherrer is currently conducting research into the development of a high brightness electron source suitable for free electron laser. The gun, planned to generate up to 5.5 Amperes of beam current, consists of a pulsed DC diode followed by a 1 1/2 cell RF gun. Using specialized codes, the performance of field emitter arrays is evaluated assuming realistic geometries. As alternatives, we examine the performance of using individual macroscopic field emission tips or conventional photo emission using copper cathodes. For these, optimized cathode geometries are presented and the performance is compared to that of field emitter arrays.

TUPMA042	Beam Parameters of the SCSS Prototype Accelerator Designed by PARMELA and Comparison with Measured Values	electron, gun, simulation, cathode	169
	T. Hara, H. Kitamura, T. Shintake, K. Togawa RIKEN Spring-8 Harima, Hyogo H. Tanaka JASRI/SPring-8, Hyogo-ken T. Tanikawa University of Hyogo, Hyogo
	The 250 MeV prototype facility of the SCSS X-FEL project was constructed in the Octorber 2005 and the machine commissioning was started in May 2006. One month later, we have succeeded in confirming the amplification of the synchrotron radiation. The electron beam parameters, such as peak current and emittance, have been designed and estimated using PARMELA. In contrast to other X-FEL projects, the SCSS injector uses a thermionic pulsed electron gun [1]. Compared with RF photocathode guns, the thermionic gun is stable and easy to handle. Its peak current, however, is smaller, and the compression of the electron bunch is necessary at early stage of the low beam energy injector. In this report, we compare the simulation and measured values, such as a bunch length and projected emittance, on the SCSS prototype accelerator. The measured beam parameters, after the bunch compression procedure and emittance degradation due to space charge, show fairly good agreement with the simulation. [1] K. Togawa, et al., “Emittance Measurement on the CeB6 Electron Gun for the SPring-8 Compact SASE Source”, Proceedings of the 2004 FEL Conference, (2004)351-354, URL: http://www. JACoW.org.

TUPMA046	Future Light Source based on Energy Recovery Linac in Japan	linac, gun, photon, factory	172
	T. Kasuga, T. Furuya, H. Kawata, Y. Kobayashi, S. Sakanaka, K. Satoh KEK, Ibaraki R. Hajima JAEA/FEL, Ibaraki-ken N. Nakamura ISSP/SRL, Chiba
	After extensive discussions on the future light source of the Photon Factory at High Energy Accelerator Research Organization (KEK), it has been concluded that a 5 GeV energy recovery linac (ERL) should be the most suitable candidate to foster cutting edge experiments and support a large variety of user needs from VUV to X-rays. On the other hand, Japan Atomic Energy Agency (JAEA), which has already built a low energy (17 MeV) ERL, also proposed its own 5-6 GeV ERL as a light source. These two institutes with a participation of the members of the Institute for Solid State Physics (ISSP) of the University of Tokyo agreed to promote an ERL-based next-generation synchrotron light source in Japan. In order to realize a 5 GeV ERL, it is necessary to construct a prototype ERL with an energy of ~200 MeV and develop several critical components such as electron guns and superconducting accelerating structures. We are planning to construct together the prototype ERL at the KEK site. An R&D team for the prototype ERL is going to be organized in collaboration with accelerator scientists from the other facilities, UVSOR and SPring-8.

TUPMA047	Development of a Photocathode DC Gun at JAEA-ERL	gun, electron, cathode, laser	175
	R. Hajima, H. Iijima, R. Nagai, N. Nishimori, T. Nishitani JAEA/ERL, Ibaraki
	An electron gun producing an e-beam with high-brightness and high average-current is a key component to realize a next-generation X-ray light source based on energy-recovery linac (ERL). In JAEA, we are developing a photocathode DC gun for a future ERL light source. The DC gun is operated at 250 kV and 50 mA at maximum, and equipped with a load-lock chamber for cathode preparation. In order to keep small emittance at high current operation, we adopt superlattice semiconductor as a photocathode. In this paper, we present the status of the gun development and future plans towards the ERL test facility to construct in collaboration with KEK.

TUPMA049	Development of an Injector to Generate a Very Short Bunch for a Super Coherent Terahertz Light Source Project	gun, cathode, simulation, sextupole	178
	T. Tanaka, K. Akiyama, H. Hama, F. Hinode, K. Kasamsook, M. Kawai, T. Muto, K. Nanbu, M. Yasuda Tohoku University, School of Scinece, Sendai N. Kumagai, H. Tanaka JASRI/SPring-8, Hyogo-ken
	A project to develop a coherent Terahertz (THz) light source is in progress at Laboratory of Nuclear Science, Tohoku University. The coherent synchrotron light in the THz region is emitted from electron bunches with a very short bunch less than 100 fs (rms) generated by a thermionic RF gun and a sophisticated bunch compressor. As an injector of this ring, we have developed an independently tunable cells (ITC) RF gun and a magnetic bunch compressor. The longitudinal phase space extracted from the ITC-RF gun can be manipulated by feeding RF microwave to cells independently. To generate a short bunch with a significant bunch charge, a magnetic compressor is used downstream from the gun. Two kinds of bunch compressors have been studied. From simulation of an injector, we have got a very short bunch length about 42 fs (rms). A prototype of the gun has been manufactured. Results of low power tests of the gun will be presented.

TUPMA052	Study on Compact DC Electron Gun using Single Crystal Cathode of LaB6	cathode, gun, electron, simulation	181
	K. Kasamsook, K. Akiyama, H. Hama, F. Hinode, M. Kawai, T. Muto, K. Nanbu, T. Tanaka, M. Yasuda Tohoku University, School of Scinece, Sendai
	A novel, compact DC gun has been designed and is currently on a test bed at LNS. Applying 50 kV high voltage for the gun, it is expected to supply a high brightness beam of which the beam current of 300 mA and the variable pulse duration from 1 to 5 ?sec. In addition, a floating bias voltage can be applied between the cathode and the wehnelt to manipulate electric field near cathode surface. In order to produce lower emittance beam, the thermionic cathode should have very much higher current density and the size of that should be very small. Consequently we have chosen single crystal LaB6 as the thermionic cathode, which can provide higher current density with good homogeneity electron emission. The design parameters and initial operating experience of the DC gun are discussed. This DC gun will be used for free electron lasers such as backward-wave oscillator, advanced accelerator researches and other experiments. Results of numerical calculations show good distribution of macroparticles in the phase space, which results from optimization of the bias voltage. A normalized rms emittance at the exit of the gun is expected to be less than 1 ? mm mrad.

TUPMA056	Injection of Beam Shaped Locally with Nonlinear Optics	injection, sextupole, octupole, septum	187
	C.-X. Wang ANL, Argonne, Illinois
	We discuss nonlinear beam shaping by octupole and sextupole to fold the tail of a Gaussian beam into its core, for the purpose of improving betatron injection in storage rings by significantly reducing the beam width at the injection septum and thus reducing beam centroid offset from the stored beam. Necessary conditions as well as challenges for such nonlinear injections are explored.

TUPMA059	Beam Dynamics Effects with Insertion Devices for the Proposed 3 GeV Ring in Taiwan	lattice, synchrotron, dipole, synchrotron-radiation	196
	H. C. Chao, C.-C. Kuo NSRRC, Hsinchu S.-Y. Lee IUCF, Bloomington, Indiana
	The effects of insertion devices on beam dynamics of storage rings were studied. We will focus on the changes of the emittance and energy spread in the presence of insertion devices. Formulas for the beam emittance and the energy spread with insertion devices are also derived, in which an intrinsic parameter depending on the design of the lattice is introduced in the calculations. Simulation results and comparisons of achromatic and non-achromatic cases in the proposed 3 GeV synchrotron radiation light source in Taiwan are shown.

TUPMA084	Ions for LHC: Status of the Injector Chain	ion, optics, injection, quadrupole	226
	D. Manglunki, A. Beuret, J. Borburgh, C. Carli, M. Chanel, L. D. Dumas, T. Fowler, M. Gourber-Pace, S. Hancock, M. Hourican, J. M. Jowett, D. Kuchler, E. Mahner, M. Martini, S. Maury, S. Pasinelli, U. Raich, A. Rey, J.-P. Royer, R. Scrivens, L. Sermeus, G. Tranquille, J. L. Vallet, B. Vandorpe CERN, Geneva
	The LHC will, in addition to proton runs, be operated with Pb ions and provide collisions at energies of 5.5 TeV per nucleon pair, i.e. more than 1.1 PeV per event, to experiments. The transformation of CERN's ion injector complex (Linac3-LEIR-PS-SPS) to allow collision of ions in LHC in 2008 is well under way. The status of these modifications and the latest results of commissioning will be presented. The remaining challenges are reviewed.

TUPMA094	Electron Cooling Rates in FNAL's Recycler Ring	electron, antiproton, pick-up, instrumentation	238
	A. V. Shemyakin, L. R. Prost Fermilab, Batavia, Illinois
	A 0.1-0.5 A, 4.3 MeV DC electron beam provides cooling of 8 GeV antiprotons in Fermilab's Recycler storage ring. The paper presents cooling rate formulas derived in the framework of a simple non-magnetized model and compares them with measurements.

TUPMA105	Transverse Matching of the SNS Linac Based on Profile Measurements	linac, beam-losses, quadrupole, proton	250
	D.-O. Jeon, P. Chu ORNL, Oak Ridge, Tennessee
	For a high intensity linac such as the SNS linac, it matters to match to minimize the beam mismatch and potential beam loss. It was observed that matching was improved through the matching technique based on the beam profile measurements from wirescanners. *SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U. S. Department of Energy.

WEZH102	Beam Instrumentation Experience at ATF	laser, extraction, radiation, electron	305
	Y. Honda KEK, Ibaraki
	Accelerator Test Facility (ATF) at KEK is a test accelerator for linear collider development. It produces a stable low emittance beam that satisfies the requirements in the ILC. Various beam instrumentations (cavity BPM, laser wire, fast feedback, XSR, ODR etc.) have been tested. This presentation will review our recent experiences.
	Slides

WEC3MA01	Experimental Verification of Halo Formation Mechanism of the SNS Front End	optics, linac, simulation, beam-losses	333
	D.-O. Jeon ORNL, Oak Ridge, Tennessee
	A new halo formation mechanism predicted by the simulation study was confirmed through a series of emittance measurement during the SNS Linac commissioning. The rms emittance and beam tail were greatly suppressed by the cure of transverse optics change. Detailed analisys and comparison of emittance measurement and simulation are presented here. *SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U. S. Department of Energy.
	Slides

WEPMA011	Design and Operating Experience of Triode Electron Guns for Industrial Electron Accelerators	gun, electron, cathode, linac	348
	A. Jain, A. R. Chindarkar, K. C. Mittal BARC, Mumbai
	The Accelerator and Pulse Power Division of BARC is presently constructing three industrial electron accelerators for radiation applications. a) a 500 keV, 10 KW Cockcroft-Walton accelerator b) a 10 MeV ,10 KW RF electron linac and c) a 3 MeV, 30 KW DC machine. While the DC accelerators require an almost parallel beam with less than 0.5 degree divergence, the RF linac gun requires a 50 keV , 2 ampere pulsed beam of low emittance Using relativistic electron optics, including space charge effects, very simple triode gun designs with flat cathode, grid and anode apertures which fulfill these requirements and are easy to fabricate experimentally are described. Our operating experience with these guns will also be described.

WEPMA015	Characteristics of Beam Extraction System of K500 Superconducting Cyclotron	extraction, cyclotron, ion, beam-transport	357
	S. Paul, R. K. Bhandari, J. Debnath, M. K. Dey, A. Dutta, C. Mallik, J. Pradhan DAE/VECC, Calcutta
	Extensive Magnetic Field measurement of the K500 Superconducting Cyclotron has been completed. In this paper we report the beam dynamical calculations along the extraction system based on the measured magnetic field data. The beam matching to the external beam transport system, for different ion species spanning the operating region is also explored.

WEPMA022	Electron Guns and Beamlines in the View of Emittance Compensation	gun, electron, space-charge, cathode	360
	S. V. Miginsky BINP SB RAS, Novosibirsk
	Space charge effect is ever of fundamental importance for low-energy parts of accelerators. Criteria of the significance of space charge effect are derived in the presentation. Simple and robust estimations of the emittance degradation in various space charge affected beamlines and electron guns were obtained analytically and numerically. Nonuniform longitudinal and transverse distribution of current, accelerating and bunching were taken into account. The parameters of optimal beamlines for space charge affected beams were estimated.

WEPMA044	Program for the Generation of High-Current RFQ	rfq, linac, space-charge, focusing	381
	V. L.SR. sista, T. Basak, R. Pande, S. Roy, P. Singh, S. C.L. Srivastava BARC, Mumbai
	In general design of the linear accelerators, the beam dynamics parameters are calculated from data describing the accelerator structure. In this approach, the desired phase advances (beam dynamics parameters) are obtained after several iterations of structure parameters. A program has been written for the generation of RFQ Linac, which is based on choosing the zero current transverse and longitudinal phase advances. Given the zero current transverse and longitudinal phase advances, the structure parameters are calculated using the analytical formulae. In this paper, we discuss the design of the high current RFQ using this procedure and compare it with that obtained from the standard codes. email: svlsr@barc.gov.in

WEPMA060	Measurements using the X-Ray and Optical Diagnostic Beamlines at the Australian Synchrotron	diagnostics, storage-ring, synchrotron, single-bunch	407
	G. LeBlanc, J. C. Bergstrom, M. J. Boland, R. T. Dowd, M. J. Spencer, Y. E. Tan ASP, Clayton, Victoria D. J. Peake, R. P. Rassool Melbourne, Melbourne
	First Light has been achieved on the diagnostic beamlines at the Australian Synchrotron 3 GeV storage ring. The X-ray Diagnostic Beamline (XDB) has been used to measured the beam size, divergence and emittance, while the Optical Diagnostic Beamline (ODB) has been used the measure the bunch length and turn-by-turn stability. Both beamlines receive dipole radiation from a bend magnet and provide continuous diagnostic data to the control room. The beamlines compliment each other with the ODB providing mainly longitudinal (temporal) information, while the XDB measures predominantly transverse (spatial) information. A brief description is given of the equipment on each beamline and the commissioning results are presented.

THYMA02	Progress in Understanding the High-gradient Limitations of Accelerating Structures	linear-collider, collider, damping, linac	544
	W. Wuensch CERN, Geneva
	CLIC main linac accelerating structures have extremely demanding high-gradient, high-power and wakefield performance requirements. The research program which has been put into place to develop such structures, as well as recent experimental and technological results are described. The current understanding of the effects which both limit the ultimate accelerating gradient and fix the practical operating gradient is presented.
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THZMA04	Status and Future of Taiwan Light Source	injection, storage-ring, feedback, synchrotron	602
	K. S. Liang, J.-R. Chen, C.-C. Kuo, G.-H. Luo, D.-J. Wang NSRRC, Hsinchu
	The Taiwan Light Source of National Synchrotron Radiation Research Center (NSRRC) has reached a very stable operation condition and productive scientific outputs. The copper Doris RF cavities were replaced with a niobium Superconducting (SC) RF cavity in order to eliminate higher-order-modes and deliver higher beam current. Superconducting wigglers were installed to provide higher flux at higher photon energy. The storage ring is now operated at 300 mA top-up mode with better than 97 % of beam availability during users shifts. The original layout of the magnets has been greatly modified to accommodate one SC wavelength shifter at the injection section, one SC wiggler at the RF cavity section, and three SC wigglers in achromatic sections in addition to the original design of one wiggler and three undulators. In view of the future scientific demands, the NSRRC is proposing to construct a new synchrotron storage ring of 3.0~3.3 GeV and ultra low emittance, the Taiwan Photon Source (TPS). The TPS will provide brilliant X-rays at 10²¹ photons/s/0.1%BW /mm2/mr2 by SC undulator upon its completion, making it the brightest synchrotron light with the finest performance in the world.
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THC3MA03	NSLS-II Design: A Novel Approach to Light Source Design	lattice, damping, dipole, wiggler	613
	S. L. Kramer, J. Bengtsson, S. Krinsky, V. Litvinenko, S. Ozaki BNL, Upton, Long Island, New York
	The NSLS-II storage ring will be a replacement for the existing NSLS light source rings, which although innovative when proposed was rapidly overtaken by storage ring design capabilities. NSLS-II design[1] takes a new approach toward providing users with the brightest beams after commissioning and a strategy of evolving to higher brightness beams as more ID devices are installed during its operating period. This is achieved not by pushing the basic lattice to lower emittance, an approach that hits severe limits in the control of the dynamic aperture of an ever increasing non-linear lattice. Our approach is rather to provide the additional emittance reduction naturally with the installation of additional user undulator's or adding high power damping wigglers. Some of the damping wigglers will have variable gap and can be used to maintain a given emittance as the additional user undulators are installed. The details on the lattice design for the high brightness beams and the control of stability of these high power beams is presented. *ozaki@bnl.gov
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FRXMA03	Achievement of ATF and its Future Plans	damping, kicker, coupling, extraction	837
	J. Urakawa KEK, Ibaraki
	The ATF (Accelerator Test Facility at KEK) International collaboration has been launched formally under the MoU (Memorandum of Understanding) from August 1, 2005, so as to maximally contribute to the world design and development efforts in the areas of particle sources, damping rings, beam focusing and beam instrumentation towards the International Linear Collider (ILC) project. I will give a talk on the recent achievement at ATF and its future plans, especially ATF2 project.

FRYMA02	Towards a Multi TeV Linear Collider; Drive Beam Generation with CTF3	linac, collider, linear-collider, acceleration	847
	H.-H. Braun CERN, Geneva
	The 3 TeV compact linear collider, CLIC, foresees an RF source based on a high current drive beam running parallel with the main linac. To generate this drive beam of very high instantaneous power a sophisticated complex consisting of a fully beam-loaded linac and several stages of beam compression is used. Although this scheme is very promising in terms of cost and power efficiency, it needs demonstration in a scaled version before construction of CLIC can be envisaged. This is the aim of the CLIC Test Facility CTF3, build by an international collaboration. CTF3 is constructed and exploited in several phases. Here we report present status, experimental achievements and future plans for CTF3.
	Slides