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Liakin, D.A.

Paper Title Page
CT02 Single Shot Measurements of the 4-Dimensional Transverse Phase Space Distribution of Intense Ion Beams at the UNILAC at GSI 56
 
  • L. Groening, W. Barth
    GSI, Gesellschaft für Schwerionenforschung, Darmstadt, Germany
  • D.A. Liakin
    ITEP, Institute for Theoretical and Experimental Physics, Moscow, Russia
 
  The UNILAC is used as an injector for the synchrotron SIS. It is designed to fill the synchrotron up to its space charge limit. The upper limit for the useful beam emittance of the UNILAC is given by the finite acceptance of the SIS during the injection process. In order to remain within this acceptance the emittance growth during beam acceleration and transportation due to space charge effects must be minimized by applying an appropriate beam focusing. Therefore, the influence of the magnetic focusing strength on the beam emittance growth was investigated experimentally for different beam currents. Measurements of transverse phase space distributions were performed before and after the Alvarez accelerator with a periodic focusing channel, respectively. In order to perform such a wide parameter scan within a reasonable time with respect to machine stability, the pepper pot technique was applied. The pepper pot method allows for single-pulse measurements. For comparison several measurements using the slit-grid technique, which averages over many pulses, were performed. Both transverse planes were measured simultaneously. Using two pepper pot devices more than 60 single shot measurements of the full 4-dimensional transverse phase space distribution were performed within 8 hours. In this paper we report on the results of the measurements and we compare them to beam dynamic simulations and we give an outlook on further developments on pepper pot devices.  
PM17 Development of a Permanent Magnet Residual Gas Profile Monitor With Fast Readout 134
 
  • T. Giacomini, P. Forck
    GSI, Gesellschaft für Schwerionenforschung, Darmstadt, Germany
  • V. Skachkov, A. Gobulev, D.A. Liakin
    ITEP, Institute for Theoretical and Experimental Physics, Moscow, Russia
  • A. Vetrov
    MSU, Moscow State University, MSU, Moscow, Russia
 
  Modern ion accelerators and storage rings require very fast beam profile measurements (turn-by-turn) with highest resolutions. We propose a new residual gas monitor, which will operate on secondary electrons whose trajectories are localized within ∅ 0.1 mm filaments along 0.1 T uniform magnetic field lines excited by a permanent magnet. The best way to adopt the resolution of 0.1 mm into the data acquisition system is the use of a CCD camera with upstream MCP-phosphor screen assembly. To realize a fast turn-by-turn beam profile measurement a photodiode readout by a 100-channel amplifier/digitizer is foreseen.  
PM27 Multifunction Test-Bench For Heavy Ion Sources 158
 
  • S. Barabin, V. Batalin, A. Kozlov, T. Kulevoy, R. Kuybida, D.A. Liakin, A. Orlov, V. Pershin, S. Petrenko, D. Selezniov, Yu. Stasevich
    ITEP, Institute for Theoretical and Experimental Physics, Moscow, Russia
 
  The new test-bench for heavy ion sources has been created in ITEP. It is planned to equip test-bench with a set of measurement devices to cover wide range of beam widths, divergences, durations, currents etc. It will provide measurements of different heavy ion beams parameters, particularly, emittance and charge state distribution. The last parameter may be measured both by the time-of-flight method and with the magnet analyzer. Two emittance measurement devices will be installed. It will be possible to use both slit/grid and CCD based "pepperpot" methods, which will give advantages of combination of classical emittance measurements with performance of the CCD based devices. The detailed description of test-bench and its equipment is presented. The first results at MEVVA ion source and beam investigations are discussed.  
PM29 A Modular VME Data Acquisition System for Counter Applications at the GSI Synchrotron 164
 
  • D.A. Liakin
    ITEP, Institute for Theoretical and Experimental Physics, Moscow, Russia
  • T. Hoffmann, P. Forck
    GSI, Gesellschaft für Schwerionenforschung, Darmstadt, Germany
 
  Particle counters perform the control of beam loss and slowly extracted currents at the heavy ion synchrotron (SIS) at GSI. A new VME/Lynx - PC/Linux based data acquisition system has been developed to combine the operating purposes beam loss measurement, spill analysis, spill structure measurement and matrix switching functionality in one single assembly. In this paper a detailed PC-side software description is presented. To achieve best system stability, the software has been divided into time critical networking and data deploying threads and low or normal priority interface tasks. Some new abilities in the fields of data computation and presentation are reported. A hardware description is presented, in detail a programmable GSI-EVENT controller, which is based on an ordinary 8 bit RISC microprocessor and which has been integrated into the system, to synchronize the data acquisition with the sophisticated “virtual accelerator” timing at GSI. First experiences gained while the commissioning of the system are discussed.