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MOPC123 Lattice Study for the Carbon Ion Synchrotron forTherapy with Electron Cooling ion, extraction, electron, synchrotron 355
 
  • S. V. Sinyatkin, V. A. Kiselev, E. B. Levichev, V. V. Parkhomchuk, V. B. Reva, V. A. Vostrikov
    BINP SB RAS, Novosibirsk
  In this paper the preliminary design of magnet lattice of the Carbon Ion Therapy Facility with electron cooling is described. The influence of misalignments of magnetic elements on ring parameters and the layout of orbit correction are estimated. The different methods of ion extractions from the synchrotron are considered, i.e., the pellet extraction, recombination extraction and the extraction on the sextupole resonance.  
 
MOPP025 Design of the Beam Extraction by Using Strip-line Kicker at KEK-ATF kicker, extraction, injection, damping 601
 
  • T. Naito, H. Hayano, K. Kubo, S. Kuroda, T. Okugi, N. Terunuma, J. Urakawa
    KEK, Ibaraki
  The developing work of the strip-line kicker system for International linear collider(ILC) is carrying out at KEK*. To confirm the performance of the kicker system, the beam extraction test by using strip-line kicker is in progress at KEK-ATF. The multi-bunch beam, which has 2.8ns bunch spacing in the damping ring, is extracted from the damping ring to the extraction line with 308ns duration. The scheme is the same as the kicker of the ILC. The bump orbit and the auxiliary septum magnet will be used with the kicker to clear the geometrical restriction. The detail of the hardware design and the basic performance of each component are presented in this paper.

*T. Naito et al. Development of the Strip-line Kicker System for ILC Damping Ring, Proceedings of PAC07, Albuquerque, New Mexico, USA, pp2772-2274.

 
 
TUPD002 Development of an Eddy Current Septum for LINAC4 simulation, linac, injection, extraction 1434
 
  • M. J. Barnes, B. Balhan, J. Borburgh, T. Fowler, B. Goddard, W. J.M. Weterings
    CERN, Geneva
  • A. Ueda
    KEK, Ibaraki
  The bump for the new PS Booster injection from the future Linac4 will be made up of a set of four pulsed dipole magnets; the first of these (BS1) must act as a septum with a thin element dividing the high-field region of the circulating beam from the field-free region through which the injected H- beam must pass. BS1 will provide a deflection of 66 mrad at 160 MeV; this will be achieved with a peak field of 630 mT and a length of 200 mm. The field must rise and fall in 40 microseconds and have a flattop of up to 120 microseconds. The ripple of the flattop should be below ±1%. This paper discusses the design of an eddy current septum for BS1.  
 
TUPP115 Variable Energy Protontherapy FFAG Accelerator extraction, injection, kicker, proton 1791
 
  • J. Fourrier, J. Pasternak
    LPSC, Grenoble
  • M. Conjat, J. Mandrillon, P. Mandrillon
    AIMA, Nice
  • F. Meot
    CEA, Gif-sur-Yvette
  A hadrontherapy accelerator assembly based on an FFAG ring and a variable energy H- cyclotron injector has been designed in the frame of the RACCAM project. The FFAG ring allows 2.1 Tm top rigidity, corresponding to 180 MeV proton top energy and 21.6 cm penetration depth and to 50 MeV per nucleon for carbon ions suitable for biological R&D). Variable energy extraction, bunch to pixel 3D scanning and multiport beam delivery are proposed in this installation. A prototype of a spiral sector scaling type of FFAG dipole is being built for proving the feasibility of the FFAG ring, subject to a second contribution in the conference. This paper will describe the accelerator assembly parameters and the beam properties.  
 
WEPC005 Design Considerations of the TPS Linac-to-booster Transfer Line booster, linac, injection, kicker 1989
 
  • H.-P. Chang, H. C. Chao, K. T. Hsu, S. Y. Hsu, D.-G. Huang, C.-C. Kuo, K.-K. Lin, W. T. Liu, Y.-C. Liu
    NSRRC, Hsinchu
  Design considerations of the linac to booster (LTB) transfer line for Taiwan Photon Source (TPS) project is described in this report. Electron beam from the linac with 150 MeV, 50 π-mm-mrad normalized emittance and 0.5% energy spread will be transferred to a booster synchrotron of 489.6 m. This LTB transfer line is designed with the flexible tuning capability and the diagnostics are included. Matching of transverse beam parameters from linac to booster is deliberated. The on-axis injection scheme with repetition rate around 2 or 3 Hz and efficiency with beta-mismatch for top-up operation is also studied.  
 
WEPC037 Preparations of BESSY for Top Up Operation injection, synchrotron, kicker, storage-ring 2067
 
  • P. Kuske, M. Abo-Bakr, W. Anders, T. Birke, K. B. Buerkmann-Gehrlein, M. Dirsat, O. Dressler, V. Duerr, F. Falkenstern, W. Gericke, R. Goergen, F. Hoffmann, T. Kamps, J. Kuszynski, I. Mueller, R. Mueller, K. Ott, J. Rahn, T. Schneegans, D. Schueler, T. Westphal, G. Wuestefeld
    BESSY GmbH, Berlin
  • D. Lipka
    DESY, Hamburg
  The synchrotron light source BESSY went into operation for users in 1998. BESSY was not designed initially to allow for Top Up operation, a mode where lost electrons are replaced after minutes while the beam shutters are open and users take data. Since 3 years the facility is improved in order to guarantee safe operation in this risky mode. The work culminated in a one week long Top Up test run at the beginning of this year. The efforts and achievements are described in detail: Improvements of the injector, the pulsed injection elements, the timing system, insertion devices, the additional safety interlocks, and the shielding of the ring.  
 
WEPC041 The Injection System of the SSRF Storage Ring injection, kicker, storage-ring, multipole 2076
 
  • H. H. Li, B. C. Jiang, L. G. Liu, X. Y. Sun, Y. Xu, W. Zhang, X. M. Zhou
    SINAP, Shanghai
  A multi-turn injection scheme with four kickers and two septa is used for injection into SSRF storage ring. The 3.5GeV electron beam from the SSRF booster is injected with 6.3 degrees horizontally. All injection elements are set in one 12m long straight section for the requirement of the top-up operation. Simulation and commissioning results will be presented in this paper, such as the injection efficiency and the disturbance on stored beam.  
 
WEPC068 Injection into the ALBA Storage Ring injection, kicker, storage-ring, booster 2151
 
  • G. Benedetti, D. Einfeld, M. Munoz, M. Pont
    ALBA, Bellaterra
  • E. Huttel
    FZK, Karlsruhe
  Injection into the ALBA Storage Ring is performed at an energy of 3 GeV in a 7 m long straight section. The injection bump is performed with four kickers. Pulsed magnets are described, in particular the active septum magnet. Tracking of particles has been simulated over a large number of turns, taking into account the magnet errors, the sextupole fields and the physical apertures all along the machine. Specific requirements for top-up injection have been examined, such as a perfect closure of the injection bump, the residual vertical field and the leakage fields from the septum.  
 
WEPC073 Layout of the Beam Switchyard at the European XFEL kicker, undulator, linac, collimation 2163
 
  • W. Decking, F. Obier
    DESY, Hamburg
  A unique feature of the European XFEL will be the possibility to distribute electron bunches of one beam pulse to different FEL beam lines. This is achieved by using a combination of fast kickers and a DC septum. Integration of a beam abortion dump allows a flexible selection of the bunch pattern at the FEL experiment, while the superconducting linear accelerator operates with constant beam-loading. We describe the principal scheme, the geometrical and optical layout and deal with stability and technical issues like the fast kicker development.  
 
WEPC077 Pulsed Magnet Systems for the SSRF Injection and Extraction kicker, injection, extraction, storage-ring 2175
 
  • M. G. Gu, Z. H. Chen, B. Liu, L. Ouyang, R. Wang, Y. Wu, Q. Yuan
    SINAP, Shanghai
  The injector and the storage ring of the Shanghai Synchrotron Radiation Facility (SSRF) have been built and the commissioning procedure and results are satisfactory. Total of fourteen pulsed magnets are used for the SSRF injection and extraction. In-vacuum ferrite kicker magnets, eddy current septa and 200ms bump magnets are offered for booster injection and extraction. A symmetric bump of stored beam is performed in one of the long straight section of the SSRF storage ring. Four identical kickers with ceramic vacuum chamber and two septa with a sheet of magnetic screening material around the stored beam are equipped for the storage ring injection. The septa can reach maximum 900 Tm field at 8600A with less than 0.01% leakage field for stored beam. And the identical 3.8 us half-sine pulse waveform is excited on the kicker magnets with 3.6kA current and exacted timing. The stability of ±0.05% (rms), low leakage field and identical bump are emphasized so that the residual closed orbit disturbance can be minimized for top-up injection.  
 
WEPC078 Eddy Current Septum Magnets for Booster Injection and Extraction and Storage Ring Injection at SSRF injection, storage-ring, booster, vacuum 2177
 
  • M. G. Gu, R. Chen, Z. H. Chen, B. Liu, L. Ouyang
    SINAP, Shanghai
  There are 6 in-vacuum eddy current septum magnets used for injection and extraction in the SSRF booster and storage ring. The booster extraction thick septum magnets generate magnetic field over 1 Tesla, special attentions were paid to coils and their support design because of the shock force and the high heat which is hard to be dissipated in vacuum environment. The good transverse homogeneity in the gap has been achieved by careful design, precise machining and accurate assembly. An extremely low leakage field on the stored beam is another key feature of these magnets thanks to the high permeability Mu metal. Magnetic field measurement was conducted with both point coil and long integral coil, and the results agreed well with the OPERA-2d/3d simulations. An inner tube with RF finger flanges at each end is added to keep the continuity of impedance for the circulating beam. There is no vacuum separation between the inner tube and magnet chamber.  
 
WEPC093 Finalized Design of the Pulsed Magnets and their PS for SESAME Ring Injection kicker, injection, vacuum, power-supply 2210
 
  • S. Varnasseri, A. Nadji
    SESAME, Amman
  • J.-P. Lavieville, P. Lebasque
    SOLEIL, Gif-sur-Yvette
  The design of the SESAME storage ring injection pulsed magnet systems have been improved in order to take benefit of the most recent realizations in Synchrotrons. These pulsed systems are optimised for the injection into the 2.5GeV storage ring of the 800 MeV electrons beam prepared by the Booster. The septum magnet is based on a direct driven septum technology, out of vacuum, with a thin vacuum chamber of rectangular cross section permitting to get a good field transverse homogeneity. The four kicker magnets will be of the window frame geometry, around a racetrack alumina vacuum chamber, integrating a forced air cooling in order to avoid significant thermal heating due to the stored beam. These magnets can be opened for backup and will be completely CEM shielded. Their pulsed power supplies will be built based on solid-state HV switches, even for short half-sine pulses generation.  
 
WEPC141 Septa and Distributor Developments for H- Injection into the Booster from Linac4 vacuum, linac, injection, booster 2338
 
  • J. Borburgh, B. Balhan, T. Fowler, M. Hourican, W. J.M. Weterings
    CERN, Geneva
  The construction of Linac4 requires the modification of the existing injection system of the CERN PS Booster. A new transfer line will transport 160 MeV H- ions to this machine. A system of 5 pulsed magnets (BIDIS) and 3 vertical septa (BISMV) will distribute and inject the Linac pulses into the four-vertically separated Booster rings. Subsequently the beam will be injected horizontally, using a local bump created with bumpers (BS magnets) to bring the injected H- beam together with the orbiting proton beam onto the stripper foil. To accommodate the injected H- beam, the first of the BS magnets will have to be a septum like device, deflecting only the orbiting beam. This paper highlights the requirements and technical issues and describes the solutions to be adopted for both the BIDIS and BISMV. The results of initial prototype testing of the BIDIS magnet will also be presented.  
 
WEPC142 Design of Pulsed Magnets for the Taiwan Photon Source kicker, vacuum, storage-ring, injection 2341
 
  • C.-H. Chang, C. K. Chan, J.-R. Chen, C.-S. Fann, M.-H. Huang, C.-S. Hwang, F.-Y. Lin, Y.-H. Liu, C.-S. Yang
    NSRRC, Hsinchu
  A new Taiwan Photon source requires a high stability pulsed magnets for the top-up mode injection operation. We present a preliminary design of the pulsed magnets used for injection into the 3 GeV storage ring. A 0.6 m long kicker magnet prototype is fabricated for testing the field performance. The field testing results are described in this work. The septum magnet with a 0.4 mm thickness stainless steel vacuum chamber is real tested at 3 Hz operation. The field performance, the stray fields and the eddy current effect are presented in this paper.  
 
WEPC163 Modification of a Spare Septum Magnet for SNS Ring Injection Dump Beam Line simulation, vacuum, proton, injection 2389
 
  • J. G. Wang
    ORNL, Oak Ridge, Tennessee
  The SNS ring injection dump septum magnet has been suffering the heaviest beam losses since the ring commissioning. These beam losses are caused by a number of design and operation problems such as incorrect location of one chicane dipole, incorrect chicane dipole setting, and inadequate aperture of the injection dump septum. We have modified a spare septum by increasing its vertical and horizontal aperture and by adding specially designed z-bumps for one of the waste beams. This paper reports the detailed modification results, including 3D particle trajectory calculations and experimental measurements.  
 
WEPP061 A Position Monitor for the Aborted Beam in KEKB kicker, diagnostics, electron, beam-losses 2659
 
  • N. Iida, M. Kikuchi, T. Mimashi, K. Mori, M. Tejima
    KEK, Ibaraki
  The beams in the KEKB rings are aborted by abort kickers, Lambertson septums and dumps. First the beams are kicked by the abort kickers rapidly in the horizontal direction to outside the beam pipe and are bent slowly in the vertical direction. At the same time horizontal magnetic fields shake the beam to protect the abort window where the kicked beam passes and protect the window from heat by the high current beam. A beam position monitor is installed in front of the dump. We can get some informations of aborted beam by the monitor. In this paper a method for monitoring the beam in the high energy ring at KEKB is described.  
 
THXG03 Upgrades to ISIS for the New Second Target Station target, proton, synchrotron, extraction 2902
 
  • J. W.G. Thomason
    STFC/RAL/ISIS, Chilton, Didcot, Oxon
  The new ISIS Second Target Station (TS-2) represents a major enhancement of the capabilities of the successful ISIS spallation neutron source, and correspondingly major enhancements have had to be made to the accelerator systems. As well as providing an outline of the new target station itself, the talk will describe the new dual harmonic RF system for the ISIS synchrotron which significantly increases the accelerated beam current to meet the needs of TS-2, and also the new proton beam transport line which diverts one out of every five pulses from the synchrotron to TS-2. In addition, the talk will summarise the substantial upgrades that have had to be made elsewhere on the ISIS accelerator system to underpin operation for at least another fifteen years, and will address possible future upgrades.  
slides icon Slides  
 
THPC015 Computational Beam Dynamics Studies for Improving the Ring Injection and Extraction Systems in SNS scattering, injection, quadrupole, coupling 3008
 
  • J. A. Holmes, S. M. Cousineau, M. A. Plum, J. G. Wang
    ORNL, Oak Ridge, Tennessee
  The ring injection and extraction systems must function as designed in order for the Spallation Neutron Source (SNS) to achieve its specified performance. In commissioning and early operations we have encountered problems that have been traced to these systems. We experienced high beam losses in and around the injection dump, the rectification of which has necessitated significant study and development by a multidisciplinary team. The results include a number of enhancements of existing features and the addition of new elements and diagnostics. The problem in the extraction region stems from tilted beam distributions observed in the ring-to-target beam transport line (RTBT) and on the target, thus complicating the control of the beam-on-target distribution. This indicates the inadvertant introdution of x-y beam coupling somewhere upstream of the RTBT. The present paper describes computational studies, using the ORBIT Code, addressed at the detailed understanding and solution of these problems.  
 
THPC047 Studies of Losses During Continuous Transfer Extraction at the CERN proton Synchrotron extraction, simulation, proton, quadrupole 3083
 
  • S. S. Gilardoni, J. Barranco
    CERN, Geneva
  Proton beams can be extracted from the CERN-PS at 14 GeV/c on five turns, using a technique called Continuous Transfer (CT). In this case, large losses due to particles scattered by an electrostatic septum used to slice the beam on five turns are observed in straight sections where the machine aperture is large enough to accommodate the circulating beam without any loss. These losses limit the maximum intensity deliverable to the SPS, like for the CERN to Gran Sasso (CNGS) neutrino program, because of the large irradiation of the site outside the PS tunnel and at the CERN fence. New simulation tools for a parametric study have been developed to improve the understanding of the observed loss pattern. A proposed solution to displace the losses in less critical section of the machine has been simulated and implemented in the CERN-PS. Simulations and experimental results of the loss study and reduction are presented.  
 
THPP001 Development of FFAG Electron Accelerator electron, extraction, acceleration, induction 3372
 
  • T. Baba, M. Takahashi, Y. Yuasa
    NHVC, Kyoto
  • Y. Mori
    KURRI, Osaka
  Electron Beam (EB) Accelerators have been used in the many industrial fields to improve physical properties of the material. Examples are wire and cable industries, rubber tire industries, foam industries, etc. EB is also widely used for medical device sterilization as a popular tool. High power, high reliability, compactness and low cost are key requirements to get popularity of the technology and to open up its application fields. The paper will present FFAG electron accelerator to meet these requirements that NHV Corporation recently developed and some of the interesting performance such as beam extraction efficiency will be discussed in the paper.  
 
THPP016 Preliminary Design of a Highly-flexible Extraction Scheme for the USR extraction, lattice, antiproton, storage-ring 3407
 
  • Ph. Schmid, K.-U. Kuehnel, C. P. Welsch
    MPI-K, Heidelberg
  • A. I. Papash
    JINR, Dubna, Moscow Region
  In the future Facility for Low-energy Antiproton and Ion Research (FLAIR) at GSI, the Ultra-low energy electrostatic Storage Ring (USR) will provide cooled beams of antiprotons and possibly also highly charged ions down to energies of only 20 keV/q. Beams with small momentum spread and low emittance will enable a wide range of hitherto impossible experiments. The large variety of planned experiments requires a highly flexible longitudinal time structure of the extracted bunches, ranging from ultra-short pulses in the nanosecond regime to quasi DC beams. In this contribution, a preliminary design of the extraction scheme is presented. Furthermore, possible solutions for the compensation of effects from the extraction region on the very-low energy beam are shown, including results from beam transport calculations.  
 
THPP070 Status of Center for Accelerator and Beam Applied Science of Kyushu University kicker, extraction, proton, cyclotron 3521
 
  • Y. Yonemura, H. Arima, N. Ikeda, K. Ishibashi, H. Ishikawa, K. Maehata, T. Okai, N. Shigyo, Y. Uozumi, G. Wakabayashi
    Kyushu University, Department of Applied Quantum Physics and Nuclear Engineering, Fukuoka
  • S. Fukumoto, Y. Kimura, H. Nakayama, A. Takagi
    KEK, Ibaraki
  • Y. Mori
    KURRI, Osaka
  • T. Noro, K. Sagara
    Kyushu University, Fukuoka
  • T. Tomimasu
    SAGA, Tosu
  A new accelerator facility of Center for Accelerator and Beam Applied Science is under construction on Ito Campus to promote research and education activities at Kyushu University. The facility consists mainly of a 10 MeV proton cyclotron as an injector and a 150 MeV Fixed Field Alternating Gradient (FFAG) accelerator, which was developed at KEK as a prototype of proton FFAG for various applications. In this paper, the status of the development of devices and the facility is described.  
 
THPP087 4 GeV H- Charge Exchange Injection into the PS2 injection, emittance, kicker, proton 3566
 
  • B. Goddard, W. Bartmann, M. Benedikt, A. Koschik, T. Kramer
    CERN, Geneva
  The proposed PS2 will accelerate protons from 4 to 50 GeV. The required beam intensity and brightness can only be achieved with a multi-turn H- charge exchange injection system, where the small emittance injected beam is used to paint the transverse phase space of the PS2 machine. This paper describes the constraints and conceptual design of the H- injection system and its incorporation into the present PS2 lattice. The requirements for the special injection system elements are described, in particular the injection chicane and painting magnet systems and the charge exchange foil. Some key performance aspects are investigated, including the stripping efficiency, expected emittance growth and beam loss arising from the simulated number of multiple foil traversals, together with estimates of foil heating.  
 
THPP102 Radiation Damage Studies for the Slow Extraction from SIS100 quadrupole, extraction, ion, beam-losses 3602
 
  • A. Smolyakov
    ITEP, Moscow
  • E. Mustafin, N. Pyka, P. J. Spiller
    GSI, Darmstadt
  During the slow extraction from SIS100 synchrotron 5% of the beam will hit the wires of the electrostatic septum and will be lost. These losses produce very high radiation damage to the superconducting quadrupole doublet situated downstream of the extraction point. These beam losses were simulated with the help of Fluka code for U28+ and Ne5+ beams. Non-zero cross-section and non-zero angular divergence were assumed for the lost beam, allowing distributed modeling of the slow extraction losses. The radiation damage to different layers of the superconducting quadrupole cables was calculated. The lifetime of the s.c. cables of the quadrupoles was found to be too short. Thus, alternative quadrupole designs with higher radiation tolerances were investigated: with stainless steel shielding of the s.c. cables and with a gap in the mid-plane between the s.c. cables.  
 
THPP103 Design of the Beam Extraction System of the New Heavy Ion Synchrotrons SIS100 and SIS300 at FAIR extraction, kicker, quadrupole, sextupole 3605
 
  • N. Pyka, U. B. Blell, P. J. Spiller, J. Stadlmann
    GSI, Darmstadt
  The proton and heavy ion synchrotrons SIS100 and SIS300 are the heart of the new FAIR facility which is under construction on the site of the present GSI. All ions from protons to uranium will be accelerated up to a magnetic rigidity of 100 Tm and 300 Tm, respectively. The design of the beam extraction system of both synchrotrons is completed and will be presented in this paper. The extraction devices of both synchrotrons are situated in one common straight section and deflect the beam vertically. SIS100 has been optimized for fast extraction by means of a distributed fast bipolar kicker system. However, slow extraction over a few seconds is also foreseen. SIS300 has been optimized for slow extraction and may generate spills of up to 100s. The slow extraction channel combines horizontal deflection by an electrostatic septum in the first stage with vertical deflection by a Lambertson septum magnet and subsequent magnetic extraction septa in the second stage. An emergency beam dumping system could be integrated in the extraction system of both machines.  
 
THPP105 Beam Commissioning Results of the RCS Injection and Extraction at J-PARC injection, extraction, emittance, kicker 3611
 
  • P. K. Saha, N. Hayashi, H. Hotchi, F. Noda, Y. Shobuda
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • H. Harada
    Hiroshima University, Graduate School of Science, Higashi-Hiroshima
  • Y. Irie
    KEK, Ibaraki
  The beam commissioning of J-PARC (Japan Proton Accelerator Research Complex) 3 GeV RCS (Rapid Cycling Synchrotron) has been started from the end of year 2007. As injection is in the very first stage, an accurate and well controlled beam at the injection strongly related to the other part of the RCS commissioning, including extraction where, an well extracted beam directly reflects the overall commissioning result. In this paper, the beam commissioning results of the RCS injection and extraction will be reported.  
 
THPP111 A 250 kHz Chopper for Low Energy High Intensity Proton Beams kicker, proton, simulation, rfq 3623
 
  • C. Wiesner, L. P. Chau, M. Droba, O. Meusel, U. Ratzinger
    IAP, Frankfurt am Main
  A neutron pulse with 1 ns pulse length and a repetition rate of 250 kHz is needed for the experiments on nuclear astrophysics using the Frankfurter Neutron source at the Stern-Gerlach-Zentrum. The time structure of the neutron flux is given by the primary proton beam witch hits a 7Li target. The creation of the required time structure on an intense proton beam of 200 mA dc with respect to emittance growth and beam losses is demanding. The pulsing of the ion source depends on the rise time of the plasma whereas the pulsing of the extraction voltage leads into high power deposition into the multi aperture extraction system. On the other hand a chopper system downstream of the RFQ results in rf power consumption due to beam loading and the problem of beam dumping at a beam power of several kW. Therefore it is planed to install a chopper as part of a resonant circuit in the LEBT – section consisting of four solenoids. Two different methods, magnetic and electric deflection, will be discussed with respect to emittance growth, beam losses and the influence on space charge compensation processes. Numerical simulations and preliminary results of experiments will be presented and compared.  
 
THPP112 Leakage Field of Septum Magnets of 3 GeV RCS at J-PARC extraction, vacuum, proton, injection 3626
 
  • M. Yoshimoto, H. Hotchi, J. Kamiya, M. Kinsho, M. Kuramochi, P. K. Saha, T. Takayanagi, T. Togashi, T. Ueno, M. Watanabe
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • H. Harada
    Hiroshima University, Graduate School of Science, Higashi-Hiroshima
  Septum magnets are installed in RCS (Rapid cycling Synchrotron) at J-PARC for the beam injection and extraction. In order to realize MW beam in the RCS ring and reduce the beam loss during the beam injection and extraction, the septum magnets have large physical aperture and are operated in DC. Thus there are high magnetic fields in the gaps during the acceleration, but the leakage fields are nevertheless suppressed down to a few Gauss to suppress the closed orbit distortion. In order to reduce the magnetic leakage field from the septa at beam orbit in the RCS ring, the silicon steel sheets are set for magnetic shield. In addition a few ring vacuum chambers are made by the magnetic stainless steel. Up to now, the development and field measurement of the septum magnets has been finished, and the beam commissioning of the RCS are carried out. In this presentation, the field measurements of the septum magnets are summarized and the influences of the leakage field upon the beam orbit are reported.  
 
THPP134 Injection and Extraction DC Magnets Power Supplies for 3GeV Rapid Cycling Synchrotron of J-PARC power-supply, extraction, injection, feedback 3676
 
  • M. Watanabe, J. Kamiya, M. Kinsho, T. Takayanagi, Y. Yamazaki, M. Yoshimoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  • K. Hirano
    JAEA/LINAC, Ibaraki-ken
  • Y. Irie
    KEK, Ibaraki
  Proton beams have been successfully accelerated to the design energy of 3 GeV in the RCS at the J-PARC*. In the injection, dump and extraction sections of the RCS, septum magnets, a quadrupole magnet, dc kicker magnets and steering magnets have been installed and operated at DC. For the septum magnets, there is little space area available for the septum coil and a magnetic shield**. Therefore the power supplies are required high excitation current. Maximum currents of the injection and dump septum magnets are less than 7 kA. The extraction septum magnets need the maximum current of 12 kA***. For saving the cost and the installation space of the extraction septum magnets power supplies, a main power supply, which excites three extraction septum magnets in series, and three auxiliary power supplies for adjusting the current to the each magnet are employed. Long-term stability and the current ripples are required to be less than the order of 100 ppm for those power supplies in order to provide the required acceptance for the beams. This presentation shows design and measurements of the the injection and extraction DC power supplies.

*JAERI Technical Report 2003-044 and KEK Report 2002-13.
**M. Yoshimoto et al. Proc. of EPAC'06.
***M. Watanabe et al. IEEE Transactions on applied superconductivity, Vol.16, No.2, 2006.