Keyword: acceleration
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PO02 GANIL Operation Status and Upgrade of SPIRAL1 ion, booster, target, ion-source 51
  • F. Chautard, O. Bajeat, P. Delahaye, M. Dubois, P. Jardin, O. Kamalou, L. Maunoury, G. Sénécal
    GANIL, Caen, France
  The GANIL facility (Caen, France) is dedicated to the acceleration of heavy ion beams for nuclear physics, atomic physics, radiobiology and material irradiation. The production of stable and radioactive ion beams for nuclear physics studies represents the main part of the activity. The exotic beams are produced by the Isotope Separation On-Line method (ISOL, the SPIRAL1 facility) with SPIRAL1 facility. It is running since 2001, producing and post-accelerating radioactive ion beams. The review of the operation from 2001 to 2011 is presented. Because of the physicist demands, the facility is about to be improved with the project Upgrade SPIRAL1. The goal of the project is to extend the range of post-accelerated exotic beams avalaible.  
PO13 Longitudinal Beam Motion in the KEK Digital Accelerator: Tracking Simulation and Experimental Results space-charge, simulation, induction, synchrotron 83
  • X. Liu
    Department of Energy Sciences, Tokyo Institute of Technology, Yokohama, Japan
  • T. Adachi
    Sokendai, Ibaraki, Japan
  • S. Harada
    Tokyo City University, Tokyo, Japan
  • T. Iwashita
    KEK, Ibaraki, Japan
  • K. Takayama, T. Yoshimoto
    TIT, Yokohama, Japan
  Beam commissioning in the KEK Digital Accelerator*, which is a small scale induction synchrotron (IS), has been conducted since the middle of 2011. Longitudinal beam motion in the induction synchrotron, which utilizes induction cells (IC) for acceleration and confinement, is characterized as barrier bucket acceleration. . These ICs are driven by the switching power supply (SPS). Pulse voltage is fully managed by the gate control for solid-state switching elements in the SPS, where FPGAs and DSPs take a key role**. A tracking code has been developed to understand the longitudinal motion affected by longitudinal space charge forces, under programmed settings of confinement and acceleration voltage. This code, where the trigger control scenario is fully implemented, calculates temporal evolution of momentum and phase of macro-particles. The simulation result has well reproduced beam commissioning results, such as bunch squeezing experiment and barrier bucket acceleration. In addition, the code is going to be applied to explain the rapid growth of micro-bunch structure in the injected ion bunch.
* T. Iwashita et al., “KEK Digital Accelerator” , Phys. Rev. ST-AB 14, 071301 (2011). And K.Takayama et al., in this conference.
** S.Harada, Ms. Thesis (TCU) (2011).
TUB03 Terminal Voltage Stabilization of Pelletron Tandem Accelerator controls, feedback, ion, electron 124
  • N.R. Lobanov, M.C. Blacksell, P. Linardakis, D. Tsifakis
    Research School of Physics and Engineering, Australian National University, Canberra, Australia
  Funding: Heavy Ion Accelerators Education Investment Fund (EIF)
A conventional corona control terminal voltage stabiliser has been investigated on the ANU 14UD tandem accelerator. The fluctuations in the charge transport of electrostatic pelletron generator and their correlation with mechanical oscillations of the chains and terminal voltage ripple have been analysed. Emphasis is placed on the performance of the two-loop feedback system and on the tuning of this system to production of high energy-resolution beams. The transfer function for the corona regulation loop has been determined and examined. The system produces the beam position at the image slit of the 90 energy-analysing magnet with long-term stability equivalent to a few hundred volts rms fluctuation of the terminal voltage. The concept of novel fast control loop utilizing the high-frequency component from the image slits to control the voltage of the last gap of high-energy acceleration tube is discussed.
slides icon Slides TUB03 [4.693 MB]  
TUC02 KEK Digital Accelerator and Recent Beam Commissioning Result injection, ion, induction, kicker 143
  • K. Takayama, T. Adachi, T. Arai, D.A. Arakara, E. Kadokura, T. Kawakubo, T. Kubo, H. Nakanishi, K. Okamura, H. Someya, A. Takagi, M. Wake
    KEK, Ibaraki, Japan
  • H. Asao, Y. Okada
    NETS, Fuchu-shi, Japan
  • Y. Barata, S. Harada
    Tokyo City University, Tokyo, Japan
  • T. Iwashita, K. Okazaki
    Nippon Advanced Technology Co. Ltd., Ibaraki-prefecture, Japan
  • K.W. Leo
    Sokendai, Ibaraki, Japan
  • X. Liu, T. Yoshimoto
    TIT, Yokohama, Japan
  The digital accelerator (DA), which is a small-scale induction synchrotron "*" requiring no high-energy injector and capable of providing various ions, was constructed at KEK"**". Beam commissioning has been carried out. The KEK-DA consists of a 200 kV high voltage terminal, in which a permanent mag. x-band ECRIS is embedded, 15 m long LEBT, ES injection kicker, and a 10 Hz rapid cycle synchrotron equipped with the induction acceleration system. An ion pulse chopped in 5 micro-sec by the newly developed Marx generator driven Einzel lens chopper"***" was guided through the LEBT and injected by the kicker in one turn. 3 micro-sec ion pulse was successfully captured with a pair of barrier voltage-pulses of 2 kV and accelerated up to 12 MeV with another flat induction-acceleration voltage-pulse through an acceleration period of 50 msec. Beam commissioning started with a He1+ ion beam of 100 microA. Details of fully digital-controlled barrier bucket trapping and induction acceleration are described, although the acceleration/extraction is still at a preliminary stage. Some of unique applications, such as laboratory space science using virtual cosmic rays, will be introduced.
* K.Takayama and R.J.Briggs (Eds), “Induction Accelerators”, (Springer, 2010).
** T. Iwashita et al., Phys. Rev. ST-AB 14, 071301 (2011).
*** T.Adachi et al., Rev. Inst. Meth. 82, 083305 (2011).
slides icon Slides TUC02 [2.126 MB]  
WEB04 Electron and Ion Beam Dynamics in the CARIBU EBIS Charge Breeder ion, electron, simulation, ion-source 172
  • C. Dickerson, S.A. Kondrashev, B. Mustapha, P.N. Ostroumov
    ANL, Argonne, USA
  • A.I. Pikin
    BNL, Upton, Long Island, New York, USA
  Funding: This work is supported by the U.S. Department of Energy, Office of Nuclear Physics, under contract number DE-AC02-06CH11357.
An Electron Beam Ion Source (EBIS) is being built to charge breed ion beams from the Californium Rare Isotope Breeder Upgrade (CARIBU) for acceleration in the Argonne Tandem Linear Accelerator System (ATLAS) at Argonne National Laboratory (ANL). The overall efficiency of the source and charge breeder system is important since CARIBU will produce many low intensity radioactive ion species. Simulations of the electron and ion beam dynamics have been used to determine the system’s expected performance. The details of these simulations and results will be presented.
slides icon Slides WEB04 [1.362 MB]  
WEC01 Production 72 MHz β=0.077 Superconducting Quarter-wave Cavities for ATLAS cavity, niobium, linac, heavy-ion 174
  • M.P. Kelly, Z.A. Conway, S.M. Gerbick, M. Kedzie, R.C. Murphy, B. Mustapha, P.N. Ostroumov, T. Reid
    ANL, Argonne, USA
  A total of eight 72 MHz β=0.077 superconducting quarter-wave cavities have recently been completed at Argonne National Laboratory. Seven of these will installed into the ATLAS superconducting heavy-ion linac as part of a beam intensity upgrade, with one remaining for the purposes of continuing to push the performance limits in these structures. Cavities were fabricated using techniques adapted the worldwide effort push niobium cavities close to the material limits. Key developments include the use of electropolishing on the complete helium-jacketed cavity. Wire EDM has been used instead of traditional niobium machining in order to minimize performance limiting defects near the weld seams. Hydrogen degassing at 600C after electropolishing has also been performed. Initial test results show practical acceleration at 4 Kelvin with cavity voltages, Vacc>3 MV/cavity and at 2 Kelvin with Bpeak>120 mT and Vacc>5 MV/cavity.  
slides icon Slides WEC01 [2.843 MB]  
WEC04 Operation of Superconducting Linac and Commissioning of the Last Linac at IUAC Delhi linac, damping, niobium, bunching 185
  • S. Ghosh, R. Ahuja, J. Antony, S. Babu, J. Chacko, A. Choudhury, G.K. Chowdhury, T.S. Datta, R.N. Dutt, R. Joshi, D. Kanjilal, S. Kar, J. Karmakar, M. Kumar, R. Kumar, D.S. Mathuria, K.K. Mistri, A. Pandey, P. Patra, P.N. Prakash, A. Rai, A. Roy, J. Sacharias, B.K. Sahu, A. Sarkar, S.S. Sonti
    IUAC, New Delhi, India
  The major part of the superconducting linac at IUAC has been operational for the past few years and the last accelerating module is in the final stage of completion. The full linac system consists of five cryostats, housing a total of twenty seven niobium quarter wave resonators. At present, the Superbuncher, the first two linac accelerating modules and the Rebuncher are operational and ion beams in the mass range 12C to 107Ag from Pelletron accelerator have been further accelerated and delivered to conduct experiments. A method of random phase focusing to select the accelerating phase of the resonators between 70° and 110° has been successfully tried to reduce the final time width of the beam bunch. Presently, to improve the accelerating fields of the linac resonators in phase locked condition, efforts are dedicated towards improvement of the cooling efficiency of the drive coupler, enhancement of the microphonics damping efficiency with mixtures of SS-balls and testing of an alternate tuning mechanism based by Piezo Crystal. The beam acceleration through the complete linac is to be performed by end of the summer of 2012.  
slides icon Slides WEC04 [2.810 MB]  
WEC05 Design Studies for a New Heavy Ion Injector Linac for FAIR linac, ion, heavy-ion, injection 191
  • B. Schlitt, W.A. Barth, G. Clemente, W. Vinzenz
    GSI, Darmstadt, Germany
  As the GSI UNILAC started operation in 1975, it will be more than 40 years old when the commissioning of the future Facility for Antiproton and Ion Research (FAIR) at GSI will start. To assure reliable operation for FAIR and to provide beams for a variety of experiments, three separate linacs are proposed: 1.) A new superconducting cw heavy-ion linac behind the upgraded high charge state injector HLI shall provide ion beams with high duty cycle and adjustable energy in the MeV/u region for the super-heavy element program as well as for further UNILAC experiments. 2.) A dedicated 70 MeV proton linac will serve as injector for the FAIR pbar physics program. 3.) To deliver high-intensity heavy-ion beams for FAIR, the existing post-stripper linac should be replaced by a new high energy linac with short beam pulses, low pulse repetition rate, and fixed end energy. Conceptual design studies for the latter machine using 108 MHz IH-type drift tube structures will be presented, including a proposal to increase the ion charge states for synchrotron injection as well as a linac beam energy upgrade using 325 MHz CH structures.  
slides icon Slides WEC05 [6.013 MB]  
THB01 New Developments in Low-Z Gas Stripper Sstem at RIKEN Radioactive Isotope Beam Factory (RIBF) ion, electron, target, cyclotron 199
  • H. Okuno, N. Fukunishi, H. Hasebe, H. Imao, O. Kamigaito, M. Kase, H. Kuboki
    RIKEN Nishina Center, Wako, Japan
  Electron stripping process from heavy ion in material is a useful tool in accelerator complex to give higher charge state of the ion, allowing its effective acceleration. This process is competed with electron capture process and reach to the equilibrium charge state. Carbon foils is convenient for charge stripper but have short lifetime due to thermal stress and sputtering in the case of high power beam of heavy ion such as uranium. Gas is basically free from lifetime but gives lower charge state due to absent of density effect. Therefore, charge stripper especially for uranium beams at 10-20 MeV/u could be a bottle-neck problem in high power heavy ion facility such as RIBF, FRIB and FAIR. A charge stripper using low-Z gas (He or H2) is an important candidate to solve the problem because the high equilibrium mean charge states for the low-Z gas stripper are expected due to the suppression of the electron capture process. This presenation will describe the results for the develeopments and tests of He gas stripper for uranium beams at 11 MeV/u.  
slides icon Slides THB01 [7.108 MB]