| Paper |
Title |
Other Keywords |
Page |
| MOYBGM01 |
Global R&D Effort for the ILC Linac Technology
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linac, cryogenics, linear-collider, collider |
12 |
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- A. Yamamoto
KEK, Ibaraki
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The presentation will cover the ongoing ILC R&D program in the field of superconducting accelerating structures, accelerator modules and rf systems. In addition to technical/scientific aspects, a view of the organisational challenges of this global R&D programme and how they are addressed will be described.
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Slides
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| MOPC043 |
Design of LINAC Based Compact X-ray Source via Inverse Compton Scattering at Waseda University
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laser, electron |
166 |
| |
- A. Masuda, T. Gowa, C. Igarashi, T. Kashino, N. Mitsuda, K. Sakaue, M. Washio
RISE, Tokyo
- H. Hayano, J. Urakawa
KEK, Ibaraki
- S. Kashiwagi
ISIR, Osaka
- R. Kuroda
AIST, Tsukuba, Ibaraki
- K. U. Ushida
RIKEN, Saitama
| |
A table-top size soft X-ray source based on inverse Compton scattering has been developed at Waseda University. We have already succeeded in generating X-rays via inverse Compton scattering between 4.6 MeV electron beam generated from a photocathode RF-gun and 1047nm Nd:YLF laser. The energy of the X-ray is within the 'water window' region which can be applied for the soft X-ray microscope for biological observation. In 2007, new RF-gun cavity with Cs-Te photocathode in place of copper has been installed. The energy of electron beam became up to 5.5MeV due to the increase of Q-value of the gun cavity. According to this achievement, generated X-ray energies will cover overall the 'water window' region. We are planning a multi-pulse inverse Compton scattering X-ray generation system in order to enhance a luminous intensity of the X-rays. For this purpose, we are considering a multi-pulse UV laser system for generating a multi-bunch electron beam, the method for beam loading compensation, and the multi-pulse IR laser system for the Compton collisions. Experimental results of X-ray generation and multi-pulse X-ray plans will be presented at the conference.
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| MOPC066 |
Optimisation of a SRF High Average Current SRF Gun
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cathode, gun, emittance, laser |
220 |
| |
- C. D. Beard, J. W. McKenzie, B. L. Militsyn, B. D. Muratori
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
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An approximately 100 mA and 10 MeV continuous wave electron injector is required to deliver high brightness electron bunches for the spontaneous and VUV radiation sources. One of possible solutions might be a Superconductive RF (SRF) gun. Optimisation of the first half cell of the gun has been carried out to maximise the acceleration whilst providing additional focussing through shaping of the cathode region to meet the design specification. In this paper, the cavity design and specification are presented together with some initial optimisations.
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| MOPC084 |
A Laser-driven Acceleration Method
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ion, plasma, laser, target |
253 |
| |
- L. Torrisi, S. Gammino, D. Margarone
INFN/LNS, Catania
- A. Borrielli, F. Caridi
INFN & Messina University, S. Agata, Messina
| |
A laser ion source (LIS) has been obtained with a repetitive pulsed laser at power density of the order of 1010 W/cm2 or higher, with pulse duration of the order of ns and repetition rate of the order of tens Hz. Any solid target can be ablated producing plasma with equivalent temperatures higher than 100 eV, densities higher than 1017/cm3 and charge states higher than 10+. Extracted current densities can be higher than 10 mA/cm2. The study of the electric fields generated inside the non equilibrium plasmas is a by-product of the research in ion generation. Ions are emitted from the plasma in the direction of the electric field with energies of the order of 50 eV/nucleon or higher, depending on the laser intensity. Emitted ions have a Boltzmann ion energy distribution depending on the ion charge state. Previous papers show that the electric field is as high as 10 MV/cm in our case. Magnetic trapping of electrons has been used to increase the ion acceleration, focusing and current. This new ion acceleration method based on LIS seems to be very interesting because it may permit to build accelerators with small dimensions and relatively low cost.
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| MOPC100 |
Design Status of the FAIR Synchrotrons SIS100 and SIS300 and the High Energy Beam Transport System
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extraction, synchrotron, beam-losses, dipole |
298 |
| |
- P. J. Spiller, U. B. Blell, O. Boine-Frankenheim, E. S. Fischer, G. Franchetti, F. Hagenbuck, I. Hofmann, J. E. Kaugerts, M. Kauschke, M. Kirk, H. Klingbeil, A. Kraemer, D. Krämer, G. Moritz, C. Omet, N. Pyka, H. Ramakers, S. Ratschow, A. Saa-Hernandez, M. Schwickert, J. Stadlmann, H. Welker
GSI, Darmstadt
- A. D. Kovalenko
JINR, Dubna, Moscow Region
| |
The present status of system- and technical design and R&D for the new heavy ion synchrotrons SIS100 and SIS300 and the HEBT system is summarized. The overall machine planning and the general layout has been completed and the detailed technical machine design has been started. Device and component specifications, technical parameter lists and technical design reports are in preparation with the goal to enable international partners or industry to finalize the component design to achieve production readiness. In the frame of international working groups the distribution and sharing of the work packages, especially of the cryomagnetic system is under discussion.
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| MOPC106 |
Injection and Acceleration of Au31+ in the BNL AGS
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ion, electron, injection, vacuum |
313 |
| |
- W. Fischer, L. Ahrens, K. A. Brown, C. J. Gardner, J. W. Glenn, H. Huang, M. Mapes, J. Morris, V. Schoefer, L. Smart, P. Thieberger, N. Tsoupas, K. L. Unger, K. Zeno, S. Y. Zhang
BNL, Upton, Long Island, New York
- C. Omet, P. J. Spiller
GSI, Darmstadt
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Injection and acceleration of ions in a lower charge state reduces space charge effects, and, if further electron stripping is needed, may allow elimination of a stripping stage and the associated beam losses. The former is of interest to the accelerators of the GSI FAIR complex, the latter for BNL RHIC collider operation at energies lower than the current injection energy. Lower charge state ions, however, have a higher likelihood of electron stripping which can lead to dynamic pressures rises and subsequent beam losses. We report on experiments in the AGS where Au31+ ions were injected and accelerated instead of the normally used Au77+ ions. Beam intensities and the average pressure in the AGS ring are recorded, and compared with calculations for dynamic pressures and beam losses. The experimental results will be used to benchmark the STRAHLSIM dynamic vacuum code and will be incorporated in the GSI FAIR SIS100 design.
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| MOPC119 |
Low-Output-Impedance RF System for the ISIS Second Harmonic Cavity
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impedance, synchrotron, beam-loading, controls |
343 |
| |
- Y. Irie, S. Fukumoto, K. Muto, A. Takagi
KEK, Ibaraki
- D. Bayley, I. S.K. Gardner, A. Seville, J. W.G. Thomason
STFC/RAL/ISIS, Chilton, Didcot, Oxon
- J. C. Dooling, D. Horan, R. Kustom, M. E. Middendorf
ANL, Argonne, Illinois
- T. Oki
Tsukuba University, Ibaraki
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Low-output-impedance RF system for the second harmonic cavity in the ISIS synchrotron has been developed by the collaboration between Argonne National Laboratory, US, KEK, Japan and Rutherford Appleton Laboratory, UK. Low output impedance is realized by the feedback from plate output to grid input of the final triode amplifier, resulting in less than 30 Ω over the frequency range of interest. Precise control of the second harmonic voltage can then be realized without considering beam loading effects. Beam test scenario in the ISIS synchrotron is discussed.
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| MOPC120 |
J-PARC RCS Non-linear Frequency Sweep Analysis
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resonance, controls, impedance, damping |
346 |
| |
- A. Schnase, K. Haga, K. Hasegawa, M. Nomura, F. Tamura, M. Yamamoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
- S. Anami, E. Ezura, K. Hara, C. Ohmori, A. Takagi, M. Toda, M. Yoshii
KEK, Ibaraki
| |
A standard method to measure the S21-transfer function of a system of amplifier and cavity involves a network analyzer and a linear or logarithmic frequency sweep. However, to characterize the transfer function of the broadband (Q=2) RCS RF system, we measure and analyze several harmonics at the same time under high power ramping conditions. A pattern driven DDS system generates frequency and amplitude as in accelerator operation. During the 20ms acceleration part of the cycle, a large memory oscilloscope captures the RF-signals. The data are analyzed off-line with a down-conversion process like in a multi-harmonic LLRF-system, resulting in multi-harmonic amplitude and phase information. Using this setup in the cavity test phase we were able to find and cure resonances before installation into the tunnel. We show examples. RCS is in the commissioning phase and has reached the milestone of acceleration to final energy and beam extraction. 10 RF systems are in operation, and the low-level RF system controls the fundamental h(2) and the second harmonic h(4). Using a multi-harmonic analysis during beam operation allows checking the RF system behavior with and without beam-loading.
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| MOPC121 |
Progress on Dual Harmonic Acceleration on the ISIS Synchrotron
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power-supply, synchrotron, proton, beam-losses |
349 |
| |
- A. Seville, D. Bayley, I. S.K. Gardner, J. W.G. Thomason, C. M. Warsop
STFC/RAL/ISIS, Chilton, Didcot, Oxon
- D. J. Adams
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
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The ISIS synchrotron at the Rutherford Appleton Laboratory in the UK is currently undergoing an RF upgrade. Four, h=4 cavities have been installed in addition to the existing 6, h=2, cavities and should be capable of increasing the operating current from 200 to 300 μA. Two of the four cavities have been in operation for the last 2 user cycles improving trapping lossess and increasing operating currents beyond 200 μA. The remaining two cavities were commissioned in the spring of 2008. This paper reports on hardware commissioning, beam tests and beam simulation results.
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| MOPC125 |
The HESR RF-system and Tests in COSY
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target, synchrotron, antiproton, injection |
361 |
| |
- R. Stassen, K. Bongardt, F. J. Etzkorn, H. Stockhorst
FZJ, Jülich
- A. Schnase
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
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Two RF cavities will be installed in the High-Energy Storage Ring (HESR) of the future International Facility for Antiproton and Ion Research (FAIR) at the GSI in Darmstadt, one “small” cavity for barrier-bucket operation and one “large” cavity to accelerate and decelerate the beam and for bunch rotation. Additionally a barrier bucket with h=1..5 will be formed by this cavity to separate the decelerated beam from the refilled beam in the high luminosity mode (HL). Both prototype cavities have been built and first RF measurements were carried out. The recent results will be presented.
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| MOPC126 |
Beam Acceleration with Full-digital LLRF Control System in the J-PARC RCS
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injection, controls, feedback, synchrotron |
364 |
| |
- F. Tamura, K. Haga, K. Hasegawa, M. Nomura, A. Schnase, M. Yamamoto
JAEA/J-PARC, Tokai-mura
- S. Anami, E. Ezura, K. Hara, C. Ohmori, A. Takagi, M. Toda, M. Yoshii
KEK, Ibaraki
| |
In the J-PARC RCS (Rapid Cycling Synchrotron) we employ a full-digital LLRF control system to accelerate an ultra-high intensity proton beam. The key feature is the multi-harmonic RF signal generation by using direct digital synthesis (DDS) technology. By employing a full-digital system, highly accurate, stable and reproductive RF voltages are generated in the wide-band RF cavities loaded by magnetic alloy (MA) cores. The beam commissioning of the J-PARC RCS has been started in October 2007. The accelerators, the linac and the RCS, show good stability. The beam orbit and the longitudinal beam shape and phase are reproductive from cycle to cycle especially thanks to the stability of the linac energy, the RCS bending field and the frequency and voltage of the RCS RF. This reproductivity makes the beam commissioning efficient. We present the examples of the orbit signals and the longitudinal current signals. Also, we discuss the longitudinal beam control performance and future plans.
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| MOPC131 |
Ions for LHC: Towards Completion of the Injector Chain
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ion, injection, proton, controls |
376 |
| |
- D. Manglunki, M. Albert, M.-E. Angoletta, G. Arduini, P. Baudrenghien, G. Bellodi, P. Belochitskii, E. Benedetto, T. Bohl, C. Carli, E. Carlier, M. Chanel, H. Damerau, S. S. Gilardoni, S. Hancock, D. Jacquet, J. M. Jowett, V. Kain, D. Kuchler, M. Martini, S. Maury, E. Métral, L. Normann, G. Papotti, S. Pasinelli, M. Schokker, R. Scrivens, G. Tranquille, J. L. Vallet, B. Vandorpe, U. Wehrle, J. Wenninger
CERN, Geneva
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The CERN LHC experimental programme includes heavy ion physics with collisions between two counter-rotating Pb82+ ion beams at a momentum of 2.76 TeV/c/nucleon per beam and luminosities as high as 1·1027 cm-2 s-1. To achieve the beam parameters required for this operation the ion accelerator chain has undergone substantial modifications. Commissioning with beam of the various elements of this chain started in 2005 and in 2007 it was the turn of the final stage, the Super-Proton-Synchrotron (SPS) following extensive changes to the low-level RF hardware. The major limitations of this mode of operation of the SPS (space charge, intra-beam scattering) are presented, together with the performance reached so far. The status of the pre-injector performance will also be reviewed together with a description of the steps required to reach nominal performance.
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| MOPC132 |
Acceleration Voltage Pattern for J-PARC RCS
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synchrotron, proton, emittance |
379 |
| |
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| MOPC133 |
Radiation Level in the J-PARC Rapid Cycling Synchrotron after First Study
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beam-losses, injection, proton, synchrotron |
382 |
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- K. Yamamoto, N. Hayashi, S. Hiroki, R. Saeki
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
- K. Satoh, M. Tejima
KEK, Ibaraki
- T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken
| |
The 3GeV RCS (Rapid-Cycling Synchrotron) in J-PARC has been commissioned in October of 2007. The most important issue in the beam study is to reduce unnecessary beam loss and to keep the beam line clean for the sake of maintenance and upgrade of the machines. In order to achieve this purpose, we observed the beam loss monitors located around the RCS beam line and observed them for beam commissioning. We also investigated the residual dose of accelerator components during an interval of beam study. From these results, we found that beam loss points were the injection junction point, the branch of H0 dump and extraction line, transverse collimators, and dispersion maximum points in the arcs. Especially, the entrance of the primary collimator chamber and the current transformer of the H0 dump line were the most radio-activated points in the RCS. To make the best use of these results for beam commissioning, we managed to minimize the beam losses and succeeded in suppressing the residual dose to a level low enough to allows us to work close to those components.
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| MOPC134 |
The Status of the J-PARC RF Systems
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synchrotron, injection, linac, controls |
385 |
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- M. Yoshii, S. Anami, E. Ezura, K. Hara, C. Ohmori, A. Takagi, M. Toda
KEK, Ibaraki
- K. Haga, K. Hasegawa, M. Nomura, A. Schnase, F. Tamura, M. Yamamoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
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The first acceleration of a proton beam at the J-PARC Rapid Cycling Synchrotron started in October 2007. The R&D for magnetic alloy (MA) loaded rf-systems to realize a high field gradient accelerating system for a rapid cycling machine has been initiated in 1996 with the aim of surpassing standard ferrite loaded cavities. The RCS RF system is broad-band and designed to cover both the RCS accelerating frequency range and the second harmonic for bunch shape manipulation. The optimum Q value of the RCS cavities is approximately 2. This is realized by combining a high-Q parallel inductor with an un-cut core configuration. The beam commissioning of the 50GeV Main Ring synchrotron will start in May 2008. Acceleration and slow-beam extraction are planned for December 2008. In case of the MR RF system, the accelerating frequency swing is small. The Q-value in the order of 20 has been selected to reduce transient beam loading due to the multiple-batch injection scheme. The MR RF cavities realize the Q-value by a cut-core configuration. The details of the RF systems and the results of beam accelerations are summarized.
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| MOPC142 |
Study of the Post Extraction Acceleration Gap in the ISIS H- Penning Ion Source
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extraction, ion, emittance, ion-source |
406 |
| |
- D. C. Faircloth, M. Whitehead, T. Wood
STFC/RAL/ISIS, Chilton, Didcot, Oxon
- C. Gabor
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
- J. K. Pozimski
STFC/RAL, Chilton, Didcot, Oxon
| |
The RAL Front End Test Stand (FETS) is being constructed to demonstrate a chopped H- beam of up to 60 mA at 3 MeV with 50 pps and sufficiently high beam quality for future high-power proton accelerators (HPPA). The injection energy into the RFQ will be in the range of 50 to 70 keV whereas the standard ISIS H- Penning ion source operates at 35 keV, therefore the post extraction acceleration voltage must be increased. In order to finalise the design of the FETS post extraction system, a study is conducted on the Ion Source Development Rig (ISDR) at ISIS. This study shows how beam transport is affected by different post extraction acceleration voltages and gap lengths. Beam, current, profile and emittance measurements are presented along with theoretical calculations.
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| MOPC143 |
Multi-beamlet Study of Beam Transport in the ISIS H- Ion Source Analysing Magnet
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extraction, ion-source, ion, plasma |
409 |
| |
- D. C. Faircloth, S. R. Lawrie, A. P. Letchford, M. E. Westall, M. Whitehead, T. Wood
STFC/RAL/ISIS, Chilton, Didcot, Oxon
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The RAL Front End Test Stand (FETS) is being constructed to demonstrate a chopped H- beam of up to 60 mA at 3 MeV with 50 pps and sufficiently high beam quality for future high-power proton accelerators (HPPA). The existing 90° analysing magnet on the ISIS H- Penning ion source does not perfectly transport the beam after extraction. The present ion source has a 10 mm x 0.6 mm slit extraction aperture. To understand how the beam is transported in the analysing magnet, new ion source aperture plates are manufactured with 5 individual holes instead of a slit. These holes produce separate beamlets that are used to study transport in the sector magnet. This paper details the experiments with the modified aperture plates on the Ion Source Development Rig (ISDR) at ISIS.
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| MOPC144 |
Installation of the Front End Test Stand High Performance H- Ion Source at RAL
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ion, ion-source, extraction, power-supply |
412 |
| |
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| MOPP022 |
Transatlantic Transport of Fermilab 3.9 GHZ Cryomodule for TTF/FLASH to DESY
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alignment, laser, survey, vacuum |
592 |
| |
- M. McGee, V. T. Bocean, J. Grimm, W. Schappert
Fermilab, Batavia, Illinois
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In an exchange of technology agreement, Fermilab built and will deliver a 3.9 GHz (3rd harmonic) cryomodule to DESY to be installed in the TTF/FLASH beamline. This cryomodule delivery will involve a combination of flatbed air ride truck and commercial aircraft transport to Hamburg Germany. A description of the isolation and damping systems that maintain alignment during transport and protect fragile components is provided. Initially, transport and corresponding alignment stability studies were performed in order to assess the risk associated with transatlantic travel of a fully assembled cryomodule. Shock loads were applied to the cryomodule by using a coldmass mockup to prevent subjecting actual critical components (such as the cavities and input couplers) to excessive forces. Accumulative and peak shock loads were applied through over-the-road testing and using a pendulum hammer apparatus, respectively. Finite Element Analysis (FEA) studies were implemented to define location of instrumentation for transport studies and provide modal frequencies and shapes. Shock and vibration measurement results of transport studies and stabilization techniques are discussed.
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| MOPP042 |
RF Kick in the ILC Acceleration Structure
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emittance, linac, focusing, alignment |
637 |
| |
- V. P. Yakovlev, I. G. Gonin, A. Latina, A. Lunin, K. Ranjan, N. Solyak
Fermilab, Batavia, Illinois
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Detailed results of estimations and simulations for the RF kick caused by input and HOM couplers of the ILC acceleration structure are presented. Results of possible beam emittance dilution caused by RF kick are discussed for the main LINAC acceleration structure, and the RF structures of the ILC bunch compressors BC1 and BC2. Methods of the RF kick reduction are discussed.
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| MOPP043 |
Transverse Wake Field Simulations for the ILC Acceleration Structure
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emittance, simulation, linac, linear-collider |
640 |
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- V. P. Yakovlev, A. Lunin, N. Solyak
Fermilab, Batavia, Illinois
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Details of wake potential simulation in the acceleration structure of ILC, including the RF cavities and input/HOM couplers are presented. Transverse wake potential dependence is described versus the bunch length. Beam emittance dilution caused by main and HOM couplers is estimated, followed by a discussion of possible structural modifications allowing a reduction of transverse wake potential.
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| MOPP093 |
Fast L-band Waveguide Phase Shifter
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insertion, scattering |
769 |
| |
- S. Kazakov, S. V. Shchelkunov
Omega-P, Inc., New Haven, Connecticut
- J. L. Hirshfield
Yale University, Physics Department, New Haven, CT
- A. Kanareykin
Euclid TechLabs, LLC, Solon, Ohio
- E. Nenasheva
Ceramics Ltd., St. Petersburg
- V. P. Yakovlev
Fermilab, Batavia, Illinois
| |
During the operation of accelerators it is often important to rapidly change the parameters of the RF system, such as cavity resonant frequency, coupling, or electrical length. For this purpose a fast L-band planar phase shifter has been designed, that has advantages compared to the coaxial scheme considered before by the authors (EPAC 06). The phase shifter is based on a new ferroelectric ceramic, whose permittivity changes with application of an external voltage. The switching time depends on only the external HV circuit and can by less than a few microseconds. The conceptual design and electrical parameters of the new phase shifter are presented, as are first results of low power measurements on a 1/3 model.
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| MOPP102 |
High Field Gradient RF System for a Spiral FFAG, RACCAM
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impedance, extraction, vacuum, injection |
793 |
| |
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| MOPP104 |
Possible Upgrade Scenario for J-PARC Ring RF
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impedance, synchrotron, power-supply, linac |
799 |
| |
- C. Ohmori, K. Hara, A. Takagi, M. Toda, M. Yoshii
KEK, Ibaraki
- K. Hasegawa, M. Nomura, A. Schnase, F. Tamura, M. Yamamoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
| |
The whole J-PARC RCS RF system is operational and during beam commissioning in 2007 the beam in RCS was successfully accelerated to final energy and then extracted. The Main Ring RF system has been installed in the tunnel. Both Ring RF systems are based on the new technology using magnetic alloy loaded cavities and have achieved higher field gradient than existing ferrite base RF systems in this frequency region. For the future upgrade of the J-PARC Main Ring, a short accelerating cycle is required to increase the average beam current. In this paper, a possible upgrade scenario for RF cavities based on improvements of the magnetic alloy ring cores will be described.
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| MOPP106 |
Study of Radiation From RF Cavities
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photon, electron, radiation, background |
805 |
| |
- R. Sandstrom
DPNC, Genève
- D. Huang
IIT, Chicago, Illinois
- J. Norem
ANL, Argonne, Illinois
| |
Essential for muon accelerators such as neutrino factories or muon colliders, ionization cooling channels use RF cavities to restore the energy lost in liquid hydrogen absorbers. One major limitation in cooling comes from electrons emitted from the cavities which can cause breakdowns or unacceptable thermal load to the liquid hydrogen vessels. In the Muon Ionization Cooling Experiment MICE, these electrons also cause background in the detectors. This paper presents simulations related to these dark currents, and analysis of data from a direct measurement of this radiation in the MuCool Test Area (MTA).
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| MOPP126 |
Experimental Characterization of a 700 MHz β=0.47 5 Cell Superconducting Cavity Prototype for Pulsed Proton Linac
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proton, linac, simulation, electron |
853 |
| |
- G. Devanz, J.-P. Charrier, S. Chel, Y. Gasser, P. Hardy, J. Plouin, J. P. Poupeau, D. Roudier
CEA, Gif-sur-Yvette
| |
A 700 MHz 5 cell elliptical cavity has been developed to accelerate a high intensity proton beam in the lower energy part of a superconducting linac, starting at 80 MeV. The cavity is stiffened in order to minimize the Lorentz detuning which limits high field pulsed operation of the flatter, low beta elliptical cavities. It is equipped with a stainless steel helium vessel. The RF tests of the cavity have been carried out at 1.8 K. Cavity performance is reported in this paper. Measurements of the RF response to mechanical excitations are also presented.
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| MOPP127 |
Commissioning of Superconducting Linac at IUAC - Initial Challenges and Solutions
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linac, vacuum, damping, scattering |
856 |
| |
- S. Ghosh, S. Babu, J. Chacko, A. Choudhury, G. K. Chowdhury, T. S. Datta, D. Kanjilal, S. Kar, M. Kumar, A. Mandal, D. S. Mathuria, R. S. Meena, R. Mehta, K. K. Mistri, A. Pandey, P. Patra, P. N. Prakash, A. Rai, A. Roy, B. K. Sahu, S. S. Sonti, J. Zacharias
IUAC, New Delhi
| |
During initial acceleration of ion beam through the first module of linac having eight superconducting (SC) niobium quarter wave resonators (QWR), energy gains were found to be much lower. Major problem encountered was limitation of accelerating fields in the QWR achieved at much higher RF power (up to 300 W) leading to cable melting, metal coating on SC surface and increased cryogenic losses. Cold leaks in the niobium-stainless steel transition assemblies and niobium tuner bellows also posed a major challenge. A novel way of damping mechanical vibration was implemented to reduce RF power. Cooling was improved by installing a hemispherical structure on the resonator. The drive coupler was redesigned to eliminate metal coating. Design of the tuner/transition flange assemblies was modified to avoid cold leak. After incorporation of these modifications, on-line beam acceleration through Linac was accomplished. Pulsed (1.3 ns) Silicon beam of 130 MeV from Pelletron accelerator was further bunched to 250 ps by SC Superbuncher. After acceleration through the linac module and subsequent re-bunching using SC Rebuncher, 158 MeV Silicon beam having pulse width of 400 ps was delivered.
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| MOPP132 |
Progress Towards Development of an L-Band SC Traveling Wave Accelerating Structure with Feedback
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feedback, coupling, resonance, linac |
871 |
| |
- A. Kanareykin
Euclid TechLabs, LLC, Solon, Ohio
- P. V. Avrakhov
LPI, Moscow
- S. Kazakov
KEK, Ibaraki
- N. Solyak, V. P. Yakovlev
Fermilab, Batavia, Illinois
| |
We describe an ongoing experimental program and progress towards development of a conceptual design for a superconducting traveling wave accelerating structure for the ILC. The accelerating gradient can be significantly improved by the use of an RF feedback system redirecting the accelerating wave that passed through the superconducting traveling wave accelerator (STWA) section back to the input of the accelerating structure. The conceptual design of the SC traveling wave accelerator has been considered by P. Avrakhov et al. [PAC07, pp.2538], where shape optimization, coupler cell design and tuning issues in the feedback loop were presented. The proposed TW structure design gives an overall 24% increase in gradient over the 1 m long standing wave structure and potentially can reach 46% if a longer structure is employed. Experimental investigation of the TW SC structure considers tests of a single cavity having the same shape as the regular cell of the full-sized STWA structure, and the same ratio of the RF fields. The details of the individual parts, joint configurations along with some developments on forming and welding of the proposed cavity shapes are discussed.
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| MOPP138 |
First Test Results from the Cornell ERL Injector Cryomodule
|
emittance, alignment, linac, booster |
883 |
| |
- M. Liepe, S. A. Belomestnykh, E. P. Chojnacki, Z. A. Conway, R. Ehrlich, R. P.K. Kaplan, V. Medjidzade, H. Padamsee, P. Quigley, J. J. Reilly, D. M. Sabol, J. Sears, V. D. Shemelin, E. N. Smith, V. Veshcherevich, D. Widger
CLASSE, Ithaca
| |
Cornell University has developed and fabricated a 5 cavity SRF injector cryomodule for the acceleration of a high current (100 mA), ultra low emittance beam. This cryomodule has been installed in the Cornell ERL prototype, and is presently under extensive test. The combination of a high beam current with emittance preservation of an ultra low emittance beam results in a multitude of challenges for the SRF system, pushing parameters well beyond present state of the art. Strong HOM damping and effective HOM power extraction is required to support the 100 mA beam current. This is achieved by placing HOM beam line absorbers between all cavities. Emittance preservation is addressed by a symmetric beam line with twin input couplers, tight cavity alignment and the option of fine alignment of cold cavities. In this paper we report on first results from the injector module test, including cavity performance tests, static heat load measurements and microphonic studies.
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| MOPP159 |
Results of Vertical Tests for the KEK-ERL Single Cell Superconducting Cavities
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linac, pick-up, insertion, superconductivity |
925 |
| |
- K. Umemori, T. Furuya, T. Takahashi
KEK, Ibaraki
- H. Sakai, K. Shinoe
ISSP/SRL, Chiba
- M. Sawamura
JAEA/ERL, Ibaraki
| |
The development of the superconducting cavities is indispensable for realizing the 5 GeV-class energy recovery linacs. The KEK-ERL cavity had been recently designed. Its features are the optimized cell shapes and adoption of the enlarged beampipes with eccentric-fluted structures. In order to confirm our cavity design, two types of single cell cavities had been fabricated. One is a center-cell type cavity, whose aim is a validation of the cell shape, and another is an end-cell type cavity, which has complex structure such as the eccentric-fluted beampipes. After applying a series of surface treatments, we had assembled the cavities and performed vertical tests at KEK D10 area. Promising results have been obtained. In this presentation, we will present the results of vertical tests for these cavities.
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| TUOBM02 |
The Development of the Separated Function RFQ Accelerator in Peking University
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rfq, simulation, focusing, impedance |
1007 |
| |
- X. Q. Yan, J.-E. Chen, J. X. Fang, S. L. Gao, Z. Y. Guo, Y. R. Lu, Z. Wang, K. Zhu
PKU/IHIP, Beijing
| |
The progress of the Separated Function RFQ (SFRFQ) accelerator, which can raise the field gradient of acceleration while maintaining the transverse focusing power sufficient for high current beam, is presented. In order to demonstrate the feasibilities of the novel accelerator, a prototype cavity was designed and constructed. Correspondingly, a code SFRFQCODEV1.0 was developed specially for cavity design and beam dynamics simulation. The prototype cavity will be verified as a post-accelerator for ISR RFQ-1000 (Integral Split Ring RFQ) and accelerate O+ from 1 MeV to 1.6 MeV. To inject a higher current oxygen beam for the prototype cavity, the beam current of ISR RFQ-1000 was upgraded to 2 mA. The status of high power and beam test of the prototype cavity are presented in this paper.
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Slides
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| TUPC052 |
Beam Phase and RF Fields Monitoring System Using Lock-In Amplifier for RIBF
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monitoring, cyclotron, ion, linac |
1173 |
| |
- R. Koyama, M. K. Fujimaki, N. Fukunishi, M. Hemmi, O. Kamigaito, M. Kase, Y. Kotaka, N. S. Sakamoto, K. Suda, T. Watanabe, K. Yamada, Y. Yano
RIKEN, Saitama
| |
The accelerator complex of the RIKEN RI Beam Factory (RIBF) consists of two injectors - heavy ion linac (RILAC and CSM) and K78 MeV AVF cyclotron - and four cyclotrons from the upstream, RRC (K540 MeV), fRC (K570 MeV), IRC (K980 MeV), and SRC (K2600 MeV). In such a multi-stage acceleration system, one of the most important factors for stable operation is to maintain the matching of beam-phases between accelerators. However, drifts of beam-phases have been frequently observed, reasons of which might be the fluctuation of RF-fields, variation of magnetic field, and so on. Hence, it is important to monitor beam-phases constantly, and we have developed a monitoring system using the commercial RF lock-in amplifier model SR844 manufactured by Stanford Research Systems. In addition, the system for monitoring the RF-fields has also been developed to investigate its stability and the correlation with beam-phases. The beam-phases at eleven phase probes installed in the beam transport lines and RF-fields of 25 cavities are monitored in a uranium acceleration. In addition, lock-in amplifiers are also used to obtain good isochronous magnetic fields of three cyclotrons in the RIBF.
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| TUPC139 |
LLRF Electronics for the CNAO Synchrotron
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controls, pick-up, synchrotron, proton |
1392 |
| |
- O. Bourrion, D. Tourres, C. Vescovi
LPSC, Grenoble
| |
The Italian National Centre for Oncological hAdrontherapy (CNAO) is undergoing its final construction phase in Pavia and will use proton and carbon ion beams to treat patients affected by solid tumours. At the hearth of CNAO is a 78 meters circumference synchrotron, capable of accelerating particle up to 400 MeV/u with a repetition rate of 0.4 Hz. Particle acceleration is done by a unique VITROVAC load RF cavity operating at a frequency between 0.3 and 3MHz and up to 3kV peak amplitude. In order to control this cavity a digital LLRF system has been designed at LPSC. It is based mainly upon Digital Signal Processors (DSPs), Field Programmable Gate Arrays (FPGA) and Direct Digital Synthesizers (DDS). The LLRF system implement both cavity control and beam control capabilities in a compact, remotely programmable and configurable, Ethernet controlled electronic module. It also allows an easy regulation loop tuning, thanks to an embedded acquisition system that stores all input and output signals during a given acceleration cycle. This paper describes the electronics architecture, lab measurements and test results obtained with the system coupled with the CNAO cavity.
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| TUPC143 |
Precise RF Control System of the SCSS Test Accelerator
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controls, feedback, radiation, electron |
1404 |
| |
- H. Maesaka, T. Fukui, N. Hosoda, T. Inagaki, T. Ohshima, Y. Otake, H. Tanaka
RIKEN/SPring-8, Hyogo
- T. Hasegawa, S. Takahashi, S. Tanaka
JASRI/SPring-8, Hyogo-ken
- M. K. Kitamura
NDS, OSAKA
| |
We present the development and performance of the low level rf control system of SCSS test accelerator (VUV-FEL facility). The FEL radiation in the wavelength region of 50-60 nm reached saturation in fall 2007. Since then, the FEL intensity fluctuation has been suppressed within 10%. This performance was achieved by stabilizing the rf phase and amplitude of the accelerator. For example, the rf phase stability of the 238 MHz cavity is achieved to be 0.03 degree rms corresponding to 350 fs. Those of other cavities such as C-band (5712MHz) accelerator are also obtained to be several 100 fs. To control the rf phase and amplitude precisely, we have developed an IQ modulator / demodulator system. To treat the baseband signal of the system, we have also developed VME high speed DAC / ADC boards. The phase skew of the IQ system is ± 1.0 degree without correction and ± 0.1 degree after correction. To suppress the slow drift of rf components, we applied a PID feedback control loop to the rf source and cavity system. We also improved temperature stabilization for the acceleration structures.
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| TUPC154 |
CERN PSB Beam Tests of CNAO Synchrotron's Digital LLRF
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synchrotron, extraction, controls, proton |
1431 |
| |
- M.-E. Angoletta, A. Findlay
CERN, Geneva
- O. Bourrion, R. Foglio, D. Tourres, C. Vescovi
LPSC, Grenoble
- C. De Martinis
INFN-Milano, Milano
- L. Falbo, S. Hunt
CNAO Foundation, Milan
| |
The Italian National Centre for Oncological hAdrontherapy (CNAO), in its final construction phase, uses proton and carbon ion beams to treat patients affected by solid tumours. At the heart of CNAO is a 78-meter circumference synchrotron that accelerates particles to up to 400 MeV/u. The synchrotron relies on a digital LLRF system based upon Digital Signal Processors (DSPs) and Field Programmable Gate Array (FPGA). This system implements cavity servoing and beam control capabilities, such as phase and radial loops. Beam tests of the CNAO synchrotron LLRF system were carried out at CERN’s Proton Synchrotron Booster (PSB) in autumn 2007, to verify the combined DSP/FPGA architecture and the beam control capabilities. For this, a prototype version of CNAO’s LLRF system was adapted to the PSB requirements. This paper outlines the prototype system layout and describes the tests carried out and their results. In particular, system architecture and beam control capabilities were successfully proven by comparison with the PSB operational beam control system and with the help of several existing beam diagnostic systems.
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| TUPP002 |
Uniform Motion Control Solution for Variety of Motion Applications
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controls, feedback, power-supply, insertion |
1526 |
| |
- J. Dedic, G. Jansa, M. Plesko, R. Sabjan
Cosylab, Ljubljana
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Control solutions for motion applications require high degree of flexibility regarding the use and connectivity. Being fairly simple or highly complex, micro- or millimeter precision, one or multiple axis… the system designer has to tackle specific interfacing issues. One platform should fit different applications and provide cost effective solutions. Flexible software platform is required on one side to satisfy control system (CS) application requirements. On the other side variety of hardware (HW)–controlled by motion controller, i.e., power stages, position feedback–also requires some degree of connection flexibility. Paper presents a design of a motion control platform that offers flexible interfacing both to CS and HW, elegant extendibility options for selection of feedback protocols, low-level direct access for engineering control and enables large distances between controller and motors.
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| TUPP006 |
Beam Test with a New Control System of Acceleration in HIMAC
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controls, lattice, synchrotron, bunching |
1538 |
| |
- M. Kanazawa
NIRS, Chiba-shi
- K. Maeda
Toshiba Corporation, Tokyo
- K. Watanabe
Chiba University, Graduate School of Science and Technology, Chiba
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In the present acceleration system in HIMAC, acceleration frequency of a direct digital synthesizer is controlled with B-clock pulses of B+ and B- signals that correspond to 0.2 Gauss increment and decrement of dipole magnetic field. In the tested new control system, we will use only clock pulse whose clock rate is locked to the power line frequency. With this simple system, it is easy to build up the acceleration control system for multiple flat-top pattern. This pattern operation is expexted to use in the next irradiation system of spot-scanning in HIMAC. In this presentation, the used system and its beam tests will be presented.
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| TUPP013 |
Synchronized Data Distribution and Acquisition System Using Reflective Memory for J-PARC 3GeV RCS
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monitoring, controls, linac, beam-losses |
1553 |
| |
- H. Takahashi, N. Hayashi
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
- M. Sugimoto
Mitsubishi Electric Control Software Corp, Kobe
| |
J-PARC 3GeV RCS inject the different parameter beam to each facilities, which are MLF and MR. Therefore, 3GeV RCS Control System must realize the monitoring and the operation that are distinguished "MLF beam" from "MR beam". And, we have developed the data distribution and acquisition system for "synchronized data" which required the distinguished monitoring and operation. We have designed and developed distribution and acquisition system using Reflective Memory (RM) for BPM data, which is one of synchronized data. There are 54 BPM, and BPM signal is processed by each BPM signal circuit (total 54 circuits). Then, we have designed that RM have 54 virtual ring memories and for a few seconds BPM data pre one virtual ring memory is buffered. And we decide BPM data is written virtual ring memory position based on "beam tag", which distributed from RM of J-PARC Timing System. This "beam tag" is synchronized across J-PARC. Thereby, 54 BPM data that written same virtual ring memory position become BPM data for identical beam. The paper presents the current status of the synchronized data distribution and acquisition system using RM.
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| TUPP039 |
Wake-field Compensation in Energy Recovery Linacs
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linac, radiation, synchrotron, synchrotron-radiation |
1628 |
| |
- G. Hoffstaetter, M. G. Billing, Y. H. Lau
CLASSE, Ithaca
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Problems created by the correlated energy spread that wake fields can produce are strongly enhanced in Energy Recovery Linacs (ERLs), as compared to conventional linacs. This is due to the fact that in ERLs the spent beam is decelerated by a potentially large factor, which increases the relative energy spread proportionally. We show how severe this problem is for the impedance budget of the x-ray ERL that Cornell plans to build, and we analyze several different possibilities to compensate the correlated energy spread involving de-phasing linac components, linear and nonlinear time-of-flight terms in different accelerator sections, or high frequency accelerating cavities. Because of the particular design, which has a turn-around loop between two sections of the linac, there are many options for these techniques which we compare and evaluate.
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| TUPP042 |
Status of the ORBIT Code: Recent Developments and Plans
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scattering, injection, collimation, synchrotron |
1637 |
| |
- J. A. Holmes, S. M. Cousineau, A. P. Shishlo
ORNL, Oak Ridge, Tennessee
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We report on recent enhancements to the physics modules of the ORBIT Code and on progress toward a new implementation of ORBIT using python. We have developed the capability to track particles through general three dimensional electromagnetic field configurations. This facility has proved essential in modeling beam transport through the complicated magnetic field regions of the SNS injection chicane and injection dump line, where beam losses are high. We have also enhanced the acceleration module to provide more flexibility for synchrotron calculations. Finally, progress continues on the migration of the ORBIT physics models to a python user environment, and we present the status of this work.
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| TUPP048 |
Collective Effects in the EMMA Non-scaling FFAG
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space-charge, emittance, simulation, beam-loading |
1652 |
| |
- S. Machida, D. J. Kelliher
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
- J. S. Berg
BNL, Upton, Long Island, New York
- S. R. Koscielniak
TRIUMF, Vancouver
| |
EMMA is an electron machine to study beam dynamics in a linear nonscaling FFAG. We wish to verify that the behavior predicted by the theory and simulation is correct. In particular, we will study, with large emittance beams, a novel accelerating mode outside an rf bucket, and the effects of crossing "resonances." In EMMA, some collective effects become a concern even though the beam stays in the ring for only 10 to 20 turns. We report studies of direct and image space charge, beam loading, and other collective effects with a tracking simulation. Space charge effects, already potentially significant in EMMA, are enhanced by the fact that the beam passes through the beam pipe off-center. There is some possibility of a negative mass instability for some operation modes. We will show several 3D simulation results for space charge and beam loading effects and pure longitudinal simulation for the negative mass instability.
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| TUPP099 |
Improvement of RFQSIM
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rfq, simulation, focusing, multipole |
1762 |
| |
- J. M. Maus, A. Schempp
IAP, Frankfurt am Main
| |
RFQSIM has constantly been developed at IAP to simulate multiple particles dynamic of RFQs which include simulations of high current applications, decelerators, debuncher and rebuncher e.g. for the medical application. The latest work to improve RFQSIM include the option to change the modulation and or the aperatur of the simulated RFQ to produce the same acceleration and or focusing efficiency than the two term potential gives for different electrode geometries. Additional work was done to improve the graphical analysis during runtime as well as the change of all routines to be compatible with the Fortran F95 standard. The maximum number of particles to be simulated was increased to 200k. The paper shows examples of results for the high current application like the of the p-linac and the new HLI injector for GSI and for transition sections.
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| TUPP129 |
Accelerator Development for Advanced Particle Beam Therapy
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synchrotron, extraction, proton, linac |
1827 |
| |
- K. Saito, K. Moriyama, H. Nihongi, H. Nishiuchi, H. Sakurabata, S. Totake, M. Umezawa
Hitachi, Ltd., Power & Industrial Systems R&D Laboratory, Ibaraki-ken
| |
Particle beam therapy has become one of the most effective modalities of cancer treatment. High reliability, high throughput and high precision irradiation are strongly demanded for the therapy system. In order to meet the requirements, we have developed several key technologies of synchrotron-based accelerator system, such as multi-harmonic RF acceleration, extracted beam intensity feedback, respiration-synchronized operation and beam tuning for spot scanning irradiation. Almost all these technologies have already been applied to the proton beam therapy system at M. D. Anderson Cancer Center. Beam specifications required for the spot scanning irradiation have successfully been achieved. In this paper, present status of the accelerator development will be described.
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| TUPP147 |
Accelerator Driven Systems for Energy Production and Waste Transmutation
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target, proton, simulation, lattice |
1854 |
| |
- C. Bungau, S. C. Tygier
Manchester University, Manchester
- R. J. Barlow
UMAN, Manchester
- R. Cywinski
University of Leeds, Leeds
| |
Due to their inherent safety features and waste transmutation potential, accelerator driven subcritical reactors (ADSRs) are the subject of research and development in almost all countries around the world. The neutrons needed to sustain fission are generated by the spallation process resulting from high energy protons impacting a target element installed at the centre of the core. In the present paper the possible benefits of FFAGs as accelerator drivers for ADSR systems are analysed. FFAGs afford fast acceleration as there is no need of synchronization between RF and magnets, high average current with large repetition rate and large acceptance. The present study also focuses on the Monte Carlo studies of the reactor core design. The impact of the subcriticallity, target material and proton beam energy on the ADSR performance was also examined. Entirely novel ADSR configurations involving multiple accelerator drivers and associated spallation targets within the reactor core have also been considered. Calculations were carried out using the GEANT4 simulation code.
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| TUPP150 |
The Radiatron: A High Average Current Betatron for Industrial and Security Applications
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betatron, focusing, electron, injection |
1860 |
| |
- S. Boucher, R. B. Agustsson, P. Frigola, A. Y. Murokh, M. Ruelas
RadiaBeam, Los Angeles
- F. H. O'Shea, J. B. Rosenzweig, G. Travish
UCLA, Los Angeles, California
| |
The fixed-field alternating-gradient (FFAG) betatron has emerged as a viable alternative to RF linacs as a source of high-energy radiation for industrial and security applications. For industrial applications, high average currents at modest relativistic electron beam energies, typically in the 5 to 10 MeV range, are desired for medical product sterilization, food irradiation and materials processing. For security applications, high power x-rays in the 3 to 20 MeV range are needed for rapid screening of cargo containers and vehicles. In a FFAG betatron, high-power output is possible due to high duty factor and fast acceleration cycle: electrons are injected and accelerated in a quasi-CW mode while being confined and focused in the fixed-field alternating-gradient lattice. The beam is accelerated via magnetic induction from a betatron core made with modern low-loss magnetic materials. Here we present the design and status of a prototype FFAG betatron, called the RadiaTron, as well as future prospects for these machines.
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| WEPC052 |
Achieving Stability Requirements for Nanoprobe and Long Beam Lines at NSLS II. A Comprehensive Study
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site, ground-motion, extraction, brightness |
2109 |
| |
- N. Simos, L. Berman, A. J. Broadbent, K. Evans-Lutterodt, M. Fallier, J. Hill
BNL, Upton, Long Island, New York
| |
Driven by beam stability requirements at the NSLS II synchrotron a comprehensive study has been launched seeking to provide assurances that nanometer level stability at critical x-ray beam-lines is achievable, given the vibration environment at the selected site. Through this effort which represents the integration of an array of field measurements and a state-of-the-art model of wave propagation, the stability of special NSLS II beam-lines that push the envelope of beam size is quantified. In particular, the effects of ground vibration at the NSLS II site are studied both deterministically and stochastically to account for the stochastic nature of the disturbances arriving at the site and interact with the ring and the experimental lines. Validated numerical models are utilized in an effort to guide the design of sensitive lines. The objective is to both minimize vibration amplification as well establish a relative stability envelope between the beam extraction and imaging locations of the sensitive NSLS II beam-lines.
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| WEPC151 |
Magnetic Field Design and Calculation for the FLNR U400R Cyclotron
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cyclotron, ion, simulation, heavy-ion |
2359 |
| |
- I. A. Ivanenko, J. Franko, B. Gikal, G. Gulbekyan, N. Yu. Kazarinov
JINR, Dubna, Moscow Region
- V. P. Kukhtin, E. A. Lamzin, S. E. Sytchevsky
NIIEFA, St. Petersburg
| |
Presently FLNR reconstructs the U400 cyclotron. The new, U400R cyclotron is intended to accelerate the ion beams with A/Z from 4 to 12 up to the energy 0.78 – 27 MeV/nucleon. The wide range of the magnetic field levels from 0.8T till 1.8T allows to make a smooth variation of the beam energy over the range ±60% from nominal. For optimization of the magnetic field the 14 pairs of radial correcting coils are used. The numerical formation of the magnetic field is carried out. At the present work the main problems and solutions of the magnetic field design are described.
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| WEPD028 |
Performance of the Superconducting Corrector Magnet Circuits during the Commissioning of the LHC
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target, extraction, cryogenics, sextupole |
2470 |
| |
- W. Venturini Delsolaro, V. Baggiolini, A. Ballarino, B. Bellesia, F. Bordry, A. Cantone, M. P. Casas Lino, C. CastilloTrello, N. Catalan-Lasheras, Z. Charifoulline, C. Charrondiere, G. D'Angelo, K. Dahlerup-Petersen, G. De Rijk, R. Denz, M. Gruwe, V. Kain, M. Karppinen, B. Khomenko, G. Kirby, S. L.N. Le Naour, A. Macpherson, A. Marqueta Barbero, K. H. Mess, M. Modena, R. Mompo, V. Montabonnet, D. Nisbet, V. Parma, M. Pojer, L. Ponce, A. Raimondo, S. Redaelli, V. Remondino, H. Reymond, A. Rijllart, R. I. Saban, S. Sanfilippo, K. M. Schirm, R. Schmidt, A. P. Siemko, M. Solfaroli Camillocci, H. Thiesen, Y. Thurel, A. Vergara-Fernández, A. P. Verweij, R. Wolf, M. Zerlauth
CERN, Geneva
- A. Castaneda, I. Romera Ramirez
CIEMAT, Madrid
- SF. Feher, R. H. Flora
Fermilab, Batavia, Illinois
| |
The LHC is a complex machine requiring more than 7400 superconducting corrector magnets distributed along a circumference of 26.7 km. These magnets are powered in 1380 different electrical circuits with currents ranging from 60 A up to 600 A. Among the corrector circuits the 600 A corrector magnets form the most diverse and differentiated magnet circuits. About 60000 high current connections had to be made. A minor fault in a circuit or one of the superconducting connections would have severe consequences for the accelerator operation. All magnets are wound from various types of Nb-Ti superconducting strands, and many contain resistors to by-pass the current in case of the transition to the normal conducting state in case of a quench, and hence reduce the hot spot temperature. In this paper the performance of these magnet circuits is presented, focussing on the quench current and quench behaviour of the magnets. Quench detection and the performance of the electrical interconnects will be dealt with. The results as measured on the entire circuits will be compared to the test results obtained during the reception tests of the individual magnets.
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| WEPD031 |
Dependence of the Static and Dynamic Field Quality of the LHC Superconducting Dipole Magnets on the Pre-cycle Ramp Rate
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injection, dipole, sextupole, multipole |
2479 |
| |
- N. J. Sammut, L. Bottura, G. Deferne, W. Venturini Delsolaro, R. Wolf
CERN, Geneva
- N. J. Sammut
University of Malta, Faculty of Engineering, Msida
| |
The allowed multipoles in the Large Hadron Collider (LHC) superconducting dipole magnets decay whilst on a constant current plateau. It is known that the decay amplitude is largely affected by the powering history of the magnet, and particularly by the pre-cycle flat top current and duration and the pre-injection preparation duration. Recently, it was observed that the decay amplitude is also highly dependent on the pre-cycle ramp rate, which has an indirect effect also on the sample of data taken at constant field along the magnet loadlines. This is an important consideration to be included in the Field Description for the LHC (FiDeL), to cope with the difference between the test procedure followed for series tests and the expected cycles during the machine operation. This paper presents the results of the measurements performed to investigate this phenomenon and describes the method included in FiDeL to represent this dependence.
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| WEPP028 |
Flexible Momentum Compaction Return Arcs for RLAs
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linac, focusing, lattice, quadrupole |
2578 |
| |
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| WEPP048 |
Recirculating Linear Muon Accelerator with Ramped Quadrupoles
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linac, optics, focusing, quadrupole |
2629 |
| |
- S. A. Bogacz
Jefferson Lab, Newport News, Virginia
- R. P. Johnson
Muons, Inc, Batavia
| |
Neutrino Factories and Muon Colliders require rapid acceleration of short-lived muons to multi-GeV and TeV energies. A Recirculating Linear Accelerator (RLA) that uses a single Linac and teardrop return arcs can provide exceptionally fast and economical acceleration to the extent that the focusing range of the RLA quadrupoles allows each muon to pass several times through each high-gradient cavity. A new concept of rapidly changing the strength of the RLA focusing quadrupoles as the muons gain energy is being developed to increase the number of passes that each muon will make in the RF cavities, leading to greater cost effectiveness. We are developing the optics and technical requirements for RLA designs, using RF cavities capable of simultaneous acceleration of both μ+ and μ- species, with pulsed Linac quadrupoles to allow the maximum number of passes.
Supported in part by DOE STTR grant DE-FG02-05ER86253
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| WEPP084 |
Fabrication of a Quadrant-type Accelerator Structure for CLIC
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linear-collider, collider, feedback, background |
2716 |
| |
- T. Higo, Y. Higashi, H. Kawamata, T. T. Takatomi, K. Ueno, Y. Watanabe, K. Yokoyama
KEK, Ibaraki
- A. Grudiev, G. Riddone, M. Taborelli, W. Wuensch, R. Zennaro
CERN, Geneva
| |
In order to heavily damp the higher order modes of an accelerator structure for CLIC, two kind of damping mechanisms are implemented in one of the designs. Here each cell is equipped with electrically coupled damping channels in addition to the magnetically coupled waveguides. This design requires an assembly of longitudinally cut four quadrants to form a structure and the parts are necessarily made with milling. Since KEK has developed a high-precision machining of X-band accelerator cells with milling and turning at the same time, the experience was extended to the milling of this quadrant. Firstly, the fabrication test of a short quadrant was performed with multiple vendors to taste the present-day engineering level of milling. Following this, a full-size quadrant is also made. In this course, some of the key features are addressed, such as flatness of the reference mating surfaces, alignment grooves, 3D profile shape of the cells, surface roughness and edge treatment. In this paper, these issues are discussed from both fabrication and evaluation point of views.
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| WEPP091 |
Injector Upgrade for the S-DALINAC
|
vacuum, linac, coupling, electron |
2731 |
| |
- T. Kuerzeder, A. Araz, M. Brunken, J. Conrad, R. Eichhorn, H.-D. Gräf, M. Hertling, F. Hug, M. Konrad, M. Platz, A. Richter, S. Sievers, T. Weilbach
TU Darmstadt, Darmstadt
- W. Ackermann, W. F.O. Müller, B. Steiner, T. Weiland
TEMF, Darmstadt
- J. D. Fuerst
ANL, Argonne, Illinois
| |
Since 1991 the superconducting Darmstadt linear accelerator S-DALINAC provides an electron beam of up to 130 MeV for nuclear and astrophysical experiments. Currently its injector delivers beams of up to 10 MeV with a current of up to 60 μA. The upgrade aims to increase both parameters to 14 MeV and 150 μA in order to allow more demanding astrophysical experiments. Therefore, a modified cryostat module equipped with two new cavities is required. Due to an increase in RF power to 2 kW the old coaxial RF input couplers, being designed for a maximum power of 500 W, have to be replaced by new waveguide couplers. We review the design principles and report on the fabrication of the coupler and the whole module.
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| WEPP098 |
Efficient Traveling-wave Accelerating Structure for Linear Accelerators
|
electron, coupling, bunching, linac |
2746 |
| |
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| WEPP110 |
Design and Operational Experience of the MICE Target
|
target, insertion, beam-losses, injection |
2764 |
| |
- C. N. Booth, P. Hodgson, L. C. Howlett, M. T. Mohammad, R. Nicholson, P. J. Smith
Sheffield University, Sheffield
- N. Schofield
University of Manchester, School of Electrical and Electronic Engineering, Manchester
| |
The MICE experiment requires a beam of low energy muons to test muon cooling. This beam will be derived parasitically from the ISIS synchrotron. A novel target mechanism has been developed which allows the insertion of a small titanium target into the proton beam halo on demand. The target must remain outside of the beam envelope during acceleration, and then overtake the beam during the last 2ms before extraction. The technical specifications are demanding, and require large accelerations and precise and reproducible location of the target in each cycle. The mechanism must also operate in a high radiation environment, and the moving parts and materials must be compatible with the stringent requirements of operating in a working accelerator. The design, and the commissioning and operational experience using this system during the first operating periods in 2008 is described.
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|
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|
| WEPP119 |
The International Design Study for a Neutrino Factory
|
target, proton, factory, linac |
2773 |
| |
- C. R. Prior
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
- J. S. Berg
BNL, Upton, Long Island, New York
- M. Meddahi
CERN, Geneva
- Y. Mori
KURRI, Osaka
| |
The International Design Study (IDS) is the successor to the International Scoping Study (ISS), which identified a baseline scenario for a Neutrino Factory. IDS was launched in August 2007, with the aim of developing the baseline to the point where a full, technical design report can be written. The accelerator complex starts with a 4 MW proton driver operating at 50 Hz producing three to five, 1-2 ns bunches per pulse. The proton beam impacts on a liquid mercury jet target; pions are generated and are captured in a solenoid channel; they decay to muons which are phase rotated and formed into trains of interleaved bunches alternating in sign. The muon bunches then undergo ionisation cooling so as to be accepted by a linac, two dogbone recirculating linacs and finally an FFAG for acceleration to 25GeV. The muons are transferred to purpose-built storage rings, with long production straights, where they decay to neutrinos which are directed to detectors at distances of about 3000 km and 7500 km. IDS will be developing this baseline design, identifying its strengths and weaknesses, and progressing the whole towards a self-consistent scenario for the final technical design report stage.
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|
| WEPP127 |
ALaDyn: a High Accuracy Code for the Laser-plasma Interaction
|
simulation, plasma, laser, electron |
2794 |
| |
|
|
| WEPP129 |
Digital Acceleration Scheme of the KEK All-ion Accelerator
|
induction, ion, synchrotron, controls |
2797 |
| |
- T. S. Dixit
GUAS/AS, Ibaraki
- Y. Arakida, T. Iwashita, K. Takayama
KEK, Ibaraki
| |
R&D works to realize an all-ion accelerator (AIA)*-capable of accelerating all ions of any possible charge state, based on the induction synchrotron concept, which was demonstrated using the KEK 12 GeV-PS in 2006 **, is going on. In the induction synchrotron, unlike an RF synchrotron, operational performance is not limited due to the frequency band-width, since the switching power supply to energize the induction acceleration system is triggered by signals obtained from the bunch monitor. For a POP experiment of AIA, argon ions will be accelerated in the KEK-500 MeV booster ring, a Rapid Cycle Synchrotron (f=20 Hz) and the RCS requires a dynamic change in the acceleration voltage. Since the induction acceleration voltage per pulse is fixed, a novel technique combining the pulse density control and intermittent operation of multi-acceleration cells has been proposed. The acceleration scheme of the AIA fully employing this technique was verified by computer simulation and demonstrated at our test facility, where a new induction acceleration cell generating an acceleration voltage pulse of 2 μsec long was triggered by a beam simulator to mimic a circulating Ar beam in the KEK-AIA
* K. Takayama, Y. Arakida, T. Iwashita, Y. Shimosaki, T. Dixit, K. Torikai, J. of Appl. Phys. 101, 063304 (2007).
**K. Takayama et al., Phys. Rev. Lett. 98, 054801 (2007).
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|
| WEPP133 |
High-gradient Multi-mode Two-beam Accelerating Structure
|
simulation, collider, coupling, linear-collider |
2806 |
| |
- S. V. Kuzikov, M. E. Plotkin
IAP/RAS, Nizhny Novgorod
- J. L. Hirshfield
Yale University, Physics Department, New Haven, CT
- S. Kazakov
Omega-P, Inc., New Haven, Connecticut
| |
A new accelerating structure which is aimed to provide gradient >150 MV/m for next generation of multi-TeV linear colliders is suggested. The structure is based on periodic system of quasi-optical cavities*. Each of these cavities is excited in several equidistantly-spaced eigen modes by the drive beam in such a way that the RF fields reach peak values only during the short time intervals when an accelerating bunch is resident in the cavities, thus exposing the cavity surfaces to strong fields for only a small fraction of time. This feature is expected to raise the breakdown and pulse heating thresholds. The proposed structure embodies most of additional attractive properties: the cavity is an all metallic structure, no transfer or coupling structures are needed between the drive and acceleration channels, the cavity fields are symmetric around the axes of the drive beam and the accelerated beam, the cavity can exhibit high transformer ratio. Calculations of single quasi-optical rectangular cavity with parameters of drive and accelerating beams close to ones adopted for the CLIC project show that high gradient as well as high efficiency are achievable.
*S. V. Kuzikov et al. "Quasi-optical accelerating structure operated with a superposition of synchronized modes," Conf. Digest of Joint 32nd IRMMW Conf., Cardiff, UK, 2007, Vol.2, p.797-798.
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|
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|
| WEPP139 |
The CTF3 Two-beam Test-stand Installation and Experimental Program
|
dipole, vacuum, quadrupole, diagnostics |
2821 |
| |
|
|
| WEPP140 |
X-band PASER Experiment
|
dipole, electron, resonance, laser |
2824 |
| |
|
|
| WEPP155 |
Laser Driven Linear Collider
|
laser, collider, plasma, damping |
2850 |
| |
- A. A. Mikhailichenko
Cornell University, Department of Physics, Ithaca, New York
| |
We continue detailed description of scheme allowing long term acceleration with >10 GeV/m in multi-cell microstructures side-illuminated by laser radiation. The basis of the scheme is a fast sweeping device for the laser bunch. After sweeping the laser bunch has a slope ~45° with respect to the direction of propagation. So the every cell of microstructure becomes excited locally only for the moments, when the particles are there. Self consistent parameters of collider based on this idea allow consideration this type of collider as a candidate for the near-future accelerator era.
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|
|
| THXG02 |
J-PARC Progress and Challenges of Proton Synchrotrons
|
linac, proton, injection, beam-losses |
2897 |
| |
- M. Kinsho
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
| |
After briefly outlining the status of the J-PARC linac, the talk should concentrate on describing the outcome of the 3 GeV J-PARC synchrotron commissioning programme, and also include discussion of the challenges of successfully running high power proton synchrotrons.
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|
|
Slides
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| THYG02 |
Results from the CLIC Test Facility CTF3 and Update on the CLIC Design
|
linac, electron, luminosity, beam-loading |
2912 |
| |
- G. Geschonke
CERN, Geneva
| |
The CLIC Test Facility CTF3 is being built and commissioned in stages. Up to now the facility consists of an electron linac, a magnetic chicane for changing bunch length, the Delay Loop and the Combiner Ring. Recent experience and commissioning results will be presented together with plans for the next steps which should lead to feasibility demonstration of CLIC technology by the year 2010. The CLIC design has been reviewed in detail. The resulting changes in parameters will be presented.
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Slides
|
|
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|
| THXM02 |
Development of the KEK-B Superconducting Crab Cavity
|
electron, superconductivity, positron, cryogenics |
2927 |
| |
- K. Hosoyama, K. Akai, K. Ebihara, T. Furuya, K. Hara, T. Honma, A. Kabe, Y. Kojima, S. Mitsunobu, Y. Morita, H. Nakai, K. Nakanishi, M. Ono, Y. Yamamoto
KEK, Ibaraki
- H. Hara, K. Okubo, K. Sennyu, T. Yanagisawa
MHI, Kobe
| |
The development of the KEK-B superconducting crab cavity, including the design, production, tests and latest parameter performances should be described in this talk.
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|
Slides
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|
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|
| THPC023 |
Optimization of the AGS Superconducting Helical Partial Snake Strength
|
resonance, polarization, betatron, simulation |
3026 |
| |
- F. Lin, H. Huang, A. U. Luccio, T. Roser
BNL, Upton, Long Island, New York
| |
Two helical partial snakes, one is superconducting (called cold snake) and one is normal conducting (called warm snake), have preserved the polarization of proton beam up to 65% at the AGS extraction energy with the inject 82% polarization. In order to overcome the spin resonances, stronger partial snake is required. However, the stronger partial snake, the more titled stable spin direction that results in stronger horizontal intrinsic resonance. The balance between raising the spin tune gap generated by the snakes and reducing the titled stable spin direction has to be considered to maintain the polarization. Because the magnetic field of the warm snake is constant, only the cold snake with a maximum 3T magnetic field can be varied to find out the optimized snake strength. The paper presents the simulation results from the spin tracking with different cold snake magnetic fields. Some experimental data are also analyzed.
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|
| THPC027 |
Pulsed RF Accelerator of Electrons with Beam Recirculation
|
linac, electron, simulation, dipole |
3038 |
| |
|
|
| THPC105 |
Self-consistent Transverse Dynamics and Interbunch Energy Exchange in Dielectric Loaded Wakefield Accelerating Structures
|
focusing, electron, transverse-dynamics, vacuum |
3224 |
| |
|
|
| THPC107 |
Beam Dynamical Issues of the KEK All-ion Accelerator
|
ion, vacuum, injection, electron |
3227 |
| |
- K. Takayama, T. Adachi, E. Nakamura, H. Someya
KEK, Ibaraki
| |
R&D works to realize an all-ion accelerator (AIA)* capable of accelerating all species of ions with any possible charge state, based on the induction synchrotron concept, which was demonstrated using the KEK 12 GeV-PS in 2006**, are going on at KEK. The KEK AIA, which is a modification of the existing KEK 500 MeV Booster Ring of a rapid cycle synchrotron, may be an injector-free accelerator. An ion beam from the high-voltage terminal of 200 kV is directly injected into the accelerator ring. Several key issues associated with the low energy injection must be addressed. Space-charge limited current due to a small relativistic b and a short life-time due to scattering with the residual molecules and eddy-current induced magnetic fields associated with guide-fields ramping from a low field level are among them. Careful considerations on them suggest that there are significant constrains on the operational performance and gives achievable beam parameters assuming the present parameters of the KEK AIA.
*K. Takayama, Y. Arakida, T. Iwashita, Y. S himosaki, T. Dixit, K. Torikai, J. of Appl. Phys. 101, 063304 (2007).
**K. Takayama et al., Phys. Rev. Lett. 98, 054801 (2007).
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|
|
| THPC128 |
Bunch by Bunch Feedback by RF Direct Sampling
|
feedback, storage-ring, controls, damping |
3287 |
| |
- T. Nakamura, K. Kobayashi
JASRI/SPring-8, Hyogo-ken
- Z. R. Zhou
USTC/NSRL, Hefei, Anhui
| |
Recent ADCs have wide analog band-width which is enough for direct sampling of the RF signal from a beam position monitor without down conversion. We employed such ADCs for our bunch-by-bunch signal processor* and performed the feedback with the direct RF sampling of the signal from a beam position monitor to detect the position of bunches. With RF direct sampling, the down conversion stage which is used in usual RF front-end circuits and is composed of mixers, filters, delays and base-band amplifiers is not necessary. This simplifies the systems, and reduces the costs and the number of the tuning parameters. The feedback system with RF direct sampling is now in operation at user mode in SPring-8.
*T. Nakamura, K. Kobayashi. "FPGA BASED BUNCH-BY-BUNCH FEEDBACK SIGNAL PROCESSOR", Proc. of ICALEPCS 05.
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|
|
|
| THPC152 |
Electro-optic Bunch Arrival Time Measurement at FLASH
|
laser, electron, diagnostics, linac |
3348 |
| |
- V. R. Arsov, M. Felber, E.-A. Knabbe, F. Loehl, B. Lorbeer, F. Ludwig, K.-H. Matthiesen, H. Schlarb, B. Schmidt, P. Schmüser, S. Schulz, B. Steffen, A. Winter, J. Zemella
DESY, Hamburg
| |
The operation of the next generation free electron lasers such as FLASH and the planned European XFEL requires drift free synchronization and femto-second stability. For this purpose an optical synchronization system has been developed, based on a mode-locked erbium-doped fiber laser, whose pulses are distributed over length stabilized fiber links. In order to evaluate the performance of the optical distribution system and the bunch arrival time monitors (BAM) an independent reference is needed. The measurement of the electro-optic (EO) response in a GaP crystal offers such a possibility. The method is destruction free and allows simultaneous determination of the peak current and the charge center of mass arrival time with femto-second precision. The measurements are performed with a 0.175 mm thick GaP crystal using 3 ps linearly chirped pulses from a Ti:Sa oscillator. The EO signal is encoded to the chirped pulse and spectrally resolved near crossed polarizers. Comparison of the EO and BAM timings provides a check of the relative accuracy of both methods, including the accuracy of the optical timing distribution system.
|
|
|
|
| THPC158 |
Measurement and Stabilization of the Bunch Arrival Time at FLASH
|
feedback, laser, controls, electron |
3360 |
| |
- F. Loehl, V. R. Arsov, M. Felber, K. E. Hacker, B. Lorbeer, F. Ludwig, K.-H. Matthiesen, H. Schlarb, B. Schmidt
DESY, Hamburg
- W. Jalmuzna
TUL-DMCS, Łódź
- S. Schulz, A. Winter, J. Zemella
Uni HH, Hamburg
- J. Szewinski
The Andrzej Soltan Institute for Nuclear Studies, Centre Swierk, Swierk/Otwock
| |
To fully exploit the experimental opportunities offered by the 10 - 30 fs long light pulses from FLASH, e.g. in pump-probe experiments, precise measurements and control of the electron-bunch arrival-time on the 10 fs scale are needed. A bunch arrival time monitor (BAM) which uses the optical synchronization system of FLASH as a reference has been developed for this purpose. The bunch induced signal from a GHz-bandwidth beam pick-up is guided into an electro-optical modulator in which the periodic laser pulse train of the optical synchronization system experiences an amplitude modulation. Detection of this modulation allows to determine the bunch arrival time with a resolution of better than 20 fs. The superconducting linac of FLASH generates trains of up to 800 bunches. The BAM signals can be used for an intra-bunch train feedback stabilizing the arrival time to better than 50 fs. The feedback is capable of generating well-defined arrival time patterns within a bunch train which are useful for overlap-scans in pump-probe experiments. First results from the feedback installed at FLASH will be presented.
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|
|
|
| THPP001 |
Development of FFAG Electron Accelerator
|
septum, electron, extraction, 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.
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|
|
|
| THPP002 |
EMMA RF Cavity Design and Prototype Testing at Daresbury
|
impedance, vacuum, kicker, electron |
3374 |
| |
- C. D. Beard, P. A. Corlett, D. M. Dykes, P. Goudket, C. Hill, P. A. McIntosh, A. J. Moss, J. F. Orrett, J. H.P. Rogers, A. E. Wheelhouse, E. Wooldridge
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
- N. Bliss
STFC/DL, Daresbury, Warrington, Cheshire
- A. E. Bogle, T. L. Grimm, A. A. Kolka
Niowave, Inc., Lansing, Michigan
| |
At PAC’07 we discussed the design of a prototype cavity to be used on EMMA*. EMMA is a prototype non-scalling FFAG. It will contain 19 RF cavities operating at 1.3 GHz with a baseline accelerating voltage of 120 kV. A prototype cavity has been manufactured by Niowave, Inc. and we will present a discussion of its RF and mechanical design. This cavity was put through low power tests, to determine frequency, tuning range, shunt impedance and Q of the cavity; and high power tests, to confirm power handling ability, when it arrived at Daresbury Laboratory this spring. The results of these tests were compared to the simulations and a bead pull was carried out to obtain the field profile. The cavities for EMMA are likely to be powered by IOTs, these will be used for the high power tests, which will demonstrate cavity operation to the required maximum of 180 kV.
*E. Wooldridge et al. "RF Cavity Development for FFAG Application on ERLP at Daresbury," Proceedings of PAC’07, Albuquerque, NM (2007).
|
|
|
|
| THPP003 |
RF System Design for the EMMA FFAG
|
controls, power-supply, coupling, linac |
3377 |
| |
- C. D. Beard, S. A. Griffiths, C. Hill, P. A. McIntosh, A. E. Wheelhouse
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
- N. Bliss, A. J. Moss, C. J. White
STFC/DL, Daresbury, Warrington, Cheshire
- D. Teytelman
Dimtel, San Jose
| |
In this report the RF system design for EMMA is described. The power source options, power supplies, waveguide distribution scheme and control system is discussed. The architecture necessary to meet the operation specifications requires a large degree of adjustment. To simplify commissioning and enhance the versatility of the machine a complex RF system is desired. This report details the RF "knobs" included to meet this.
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|
|
|
| THPP004 |
EMMA - the World's First Non-scaling FFAG
|
extraction, injection, kicker, diagnostics |
3380 |
| |
|
|
| THPP005 |
Orbit Distortion and its Correction in a Non-scaling FFAG
|
quadrupole, closed-orbit, injection, lattice |
3383 |
| |
- D. J. Kelliher, S. Machida
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
| |
The wide variation in betatron tune over a rapid acceleration time presents particular difficulties in orbit correction in a non-scaling FFAG. Due to the fact that the phase advance between an error source and the corrector magnets varies during acceleration, and assuming that the corrector magnets' strengths must be constant during the short acceleration period, it is clear that conventional harmonic correction is ineffective. We propose a method to determine the magnet and BPM misalignments in a non-scaling FFAG. By running the beam at fixed energy over many turns, and assuming no other error sources exist, the BPM measurements allow the misalignments to be calculated (assuming that there are as many BPMs as error sources). We show that it is also possible to calculate the BPM misalignment error if the beam is run at two fixed energies. This is due to a characteristic property of non-scaling FFAGs - the variation of the phase shift, and hence the response of the BPM measurements to magnet misalignments, with momentum. Having estimated the magnet misalignments, a local correction is made and a tracking study carried out to calculate the reduction in orbit distortion that results.
|
|
|
|
| THPP008 |
Hamiltonian Approach to the Dynamics of Particles in Non-scaling FFAG Accelerators
|
lattice, betatron, focusing, proton |
3392 |
| |
|
|
| THPP011 |
Beam Acceleration Studies of Proton NS-FFAG
|
resonance, lattice, emittance, proton |
3398 |
| |
- T. Yokoi, J. H. Cobb
OXFORDphysics, Oxford, Oxon
- K. J. Peach, S. L. Sheehy
JAI, Oxford
| |
The NS-FFAG is a novel idea of a fixed field accelerator which has advantages in flexible design and machine operation for fixed field accelerator. However, due to the large tune variation with energy, fast acceleration is a key issue to circumvent the resonance problem in a linear NS-FFAG. At the moment, there is no numerical study of how fast it needs be. In this paper, using a lattice of a NS-FFAG for particle therapy, results of tracking study including acceleration rate, positioning tolerance are presented.
|
|
|
|
| THPP019 |
Adjustment of a New Pre-stripping Section the Multicharge Ion Linear Accelerator (MILAC)
|
ion, simulation, focusing, vacuum |
3410 |
| |
- O. F. Dyachenko, V. A. Bomko, Ye. V. Ivakhno, A. P. Kobets, V. I. Misjura, V. V. Mytrochenko, A. V. Zabotin, B. V. Zajtsev
NSC/KIPT, Kharkov
| |
In the Kharkov Institute of Physics and Technology the works on commissioning of a new prestripping section (A/q = 4), intend for accelerating a high current beam of light ions from 30 keV/u to 975 keV/u come to the end. Results of final tuning of irregular interdigital accelerating structure with alternating phase focusing and stepped changing the synchronous phase along the focusing period are presented. Process of preliminary adjustment of structure by means of traditional developed earlier methods: the additional current-carrying stems and the end resonant tuning elements (ERTEs) is described. New effective inductance-capacitor tuning devices as rods located on the drift tube side, opposite to their holders («contrivance») are developed and their use in real structure is shown. «Contrivances» have proved as the effective element of tuning locally influencing value of an electric field in the nearest gaps and lowering resonant frequency without noticeable worsening of electrodynamic characteristics of resonant system.
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|
|
|
| THPP020 |
Progress in the ALPI -PIAVE Low-beta Section Upgrade
|
linac, heavy-ion, ion, controls |
3413 |
| |
- A. Facco, F. Scarpa, D. Zenere
INFN/LNL, Legnaro, Padova
| |
The low-b section of the PIAVE-ALPI superconducting linac is being upgraded in order to increase its energy gain from approximately 10 to about 20 MeV/q. This large increase of the accelerating voltage will be obtained by increasing by 20% the number of low-beta bulk niobium quarter-wave resonators and by upgrading the old rf system, underdimensioned in comparison with the resonator performance. This will lead to a significant enhancement of the linac capabilities, including the possibility of acceleration well above the Coulomb barrier heavy ions with any mass number. Status and technical details of the upgrade program will be described.
|
|
|
|
| THPP022 |
IH Linac with Higher-order Modes
|
linac, ion, resonance, heavy-ion |
3419 |
| |
- N. Hayashizaki, T. Hattori
RLNR, Tokyo
| |
As one of a drift tube type linac, an Interdigital H-type (IH) linac has been applied for ion acceleration in low beta range. It can realize a resonant cavity of convenient size at low frequency band and higher shunt impedance at low velocity range. These characteristics are advantageous especially for heavy ion acceleration; therefore, this structure has been applied for heavy ion cancer therapy. The RF field is resonated in TE111 mode and the electric field does not have the axial field component. The accelerating field is excited by using the electrode of Interdigital shape. In order to apply this structure to intermediate beta range, we propose a IH linac with the TE11n mode of the higher-order mode (HOM). Although the operating frequency becomes higher by using HOM, it is convenient to accelerate ion beam of intermediate energy. The design of the cavity structure and the possibility are presented.
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|
|
|
| THPP031 |
Upgrade of the ISAC DTL Tuning Procedure at TRIUMF
|
linac, simulation, diagnostics, ion |
3440 |
| |
- M. Marchetto, J. Berring, R. E. Laxdal
TRIUMF, Vancouver
| |
The TRIUMF ISAC facility has two variable energy heavy ion linacs as post accelerators for radioactive ion beams. The ISAC I linac is a warm IH-DTL with five accelerating tanks and three bunchers, the ISAC II one uses twenty independently phased superconducting cavities. The first linac operates between 150 keV/u and 1.8 MeV/u; the second boosts the 1.5 MeV/u injected beam by 20 MV. The DTL is tuned based on the energy beam profile given by an analysing magnet. The SC linac is tuned on energy and time profiles with a diagnostic based on a gold foil scattering ions to a silicon detector (SID). The SID requires lower beam intensity. Furthermore the tuning time is reduced and streamlined by means of a MATLAB graphical user interface (GUI). This GUI uses a simple cosine model to characterize the energy gain versus RF phase of each cavity. Based on this we have pursued a new tuning procedure for the DTL using a gold foil/SID diagnostic. The more complex RF structures of the DTL require measurements and beam dynamics simulations (with LANA code) to produce a model for a dedicated GUI. In the paper we describe the two existing tuning methods and present new DTL procedure and interface.
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|
|
|
| THPP047 |
Prototype of the High Voltage Section for the 2 MeV Electron Cooler at COSY
|
electron, feedback, controls, power-supply |
3467 |
| |
- J. Dietrich
FZJ, Jülich
- M. I. Bryzgunov, A. D. Goncharov, V. V. Parkhomchuk, V. B. Reva, D. N. Skorobogatov
BINP SB RAS, Novosibirsk
| |
The design, construction and installation of a 2 MeV electron cooling system for COSY-Juelich is proposed to further boost the luminosity even with strong heating effects of high-density internal targets. In addition the 2 MeV electron cooler for COSY is intended to test some new features of the high energy electron cooler for HESR at FAIR/GSI. The design of the 2 MeV electron cooler will be accomplished in cooperation with the Budker Institute of Nuclear Physics in Novosibirsk, Russia. The design and first experiments of a new developed prototype of the high voltage section, consisting of a gas turbine, magnetic coils and high voltage generator with electronics is reported.
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|
|
|
| THPP068 |
Acceleration in spiral FFAG using field map data
|
extraction, injection, proton, resonance |
3515 |
| |
- J. Pasternak, J. Fourrier
LPSC, Grenoble
- F. Meot
CEA, Gif-sur-Yvette
| |
This paper presents beam dynamics studies regarding the variable energy operation of a spiral scaling FFAG (Fixed Field Alternating Gradient) accelerator designed for producing 70 to 180 MeV protons and acceleration simulations for different operation modes, corresponding to different extraction energies.
|
|
|
|
| THPP069 |
Status of the Superconducting Ring Cyclotron at RIKEN RI Beam Factory
|
cyclotron, ion, extraction, heavy-ion |
3518 |
| |
- K. Yamada, M. K. Fujimaki, N. Fukunishi, A. Goto, H. Hasebe, K. Ikegami, O. Kamigaito, M. Kase, K. Kumagai, T. Maie, M. Nagase, J. Ohnishi, N. S. Sakamoto, Y. Yano, S. Yokouchi
RIKEN, Wako, Saitama
- H. Okuno
RIKEN/RARF/CC, Saitama
| |
A superconducting ring cyclotron (SRC) was successfully commissioned to work as the final energy booster of the RI beam factory (RIBF) in RIKEN. SRC is the world's first ring cyclotron that uses superconducting magnets, and has the strongest beam bending force among the cyclotrons. It can boost the ion beam energy up to 440 MeV/nucleon for light ions and 350 MeV/nucleon for very heavy ions such as uranium nuclei to produce intense radioactive beams. The ring cyclotron consists of 6 major superconducting sector magnets with a maximum field of 3.8T. The total stored energy is 240MJ, and its overall sizes are 19 m diameter, 8 m height and 8,100 tons. The magnet system assembly was completed in August 2005, and successfully reached the maximum field in November 2005. After magnetic field measurements for two months, the other hardware than the superconducting magnets was installed. The first beam was extracted from SRC on 12/28/2006. From May 2007 we started to supply uranium beams to nuclear scientist to produce RI beams. This talk will describe the milestones that were achieved during the commissioning as well as some of the issues that still need to be resolved.
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|
|
|
| THPP080 |
A Superconducting CH-Linac for IFMIF
|
linac, rfq, focusing, beam-losses |
3548 |
| |
|
|