Author: Forck, P.
Paper Title Page
MOPP003 Beam Current Measurements with Sub-Microampere Resolution using CWCT and BCM-CW-E 62
  • F. Stulle, L. Dupuy, E.T. Touzain
    BERGOZ Instrumentation, Saint Genis Pouilly, France
  • W.A. Barth, P. Forck, M. Miski-Oglu, T. Sieber
    GSI, Darmstadt, Germany
  The CWCT current transformer and its accompanying BCM-CW-E electronics allow accurate, high-resolution beam current measurements. This is achieved by combining a high-droop current transformer with low-noise sample-and-hold electronics. Thanks to a fast response time on the microseconds level the system can be applied not only to CW beams but also macropulses. Pulse repetition rates may range from 10MHz to 500MHz, rendering CWCT and BCM-CW-E suitable for a wide variety of accelerators. We report on test bench measurements achieving sub-microampere resolution. And we discuss results of beam measurements performed at the cwLINAC (GSI), which confirm the expected performance.  
poster icon Poster MOPP003 [6.507 MB]  
DOI • reference for this paper ※  
About • paper received ※ 04 September 2019       paper accepted ※ 08 September 2019       issue date ※ 10 November 2019  
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MOPP027 First Beam-based Test of Fast Closed Orbit Feedback System at GSI SIS18 153
  • R. Singh, A. Doring, P. Forck, K. Lang, S.H. Mirza, D. Rodomonti, D. Schupp, M. Schwickert, H. Welker
    GSI, Darmstadt, Germany
  • A. Bardorfer
    I-Tech, Solkan, Slovenia
  Funding: European Unions Horizon 2020 Research and Innovation programme under Grant Agreement No. 730871 (ARIES). German Academic Exchange Service under Personal Reference No. 91605207.
The SIS18 synchrotron of GSI will be used as a booster ring for the SIS100 synchrotron built in the scope of the FAIR project. In order to preserve the beam quality during the whole acceleration ramp, a new closed orbit feedback (COFB) system is implemented at the SIS18 which operates with the existing BPMs and steerer magnets. The system aims for a bandwidth of several 100 Hz and robustness against the variation of the response matrix and the beam rigidity during the ramp. The architecture of the system and the results of the first beam-based test of the COFB hardware are presented. As a first step, the orbit correction is performed over the entire ramp using the response matrix corresponding to injection energy only taking the beam rigidity into account. Experimental observations of the bandwidth limitations arising from the temporal delay of the steerer power supplies and the spatial model variation during the ramp are compared with simulations. It is found that the temporal and the spatial model mismatch have similar effect on the achievable bandwidth of the COFB.
DOI • reference for this paper ※  
About • paper received ※ 07 September 2019       paper accepted ※ 08 September 2019       issue date ※ 10 November 2019  
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MOPP038 The Beam Diagnostics Test Bench for the Commissioning of the Proton Linac at FAIR 197
  • S. Udrea, P. Forck, C.M. Kleffner, K. Knie, T. Sieber
    GSI, Darmstadt, Germany
  A dedicated proton injector for FAIR (the pLinac) is presently under construction at GSI Darmstadt. This accelerator is designed to deliver a beam current of up to 70 mA with a final energy of 68 MeV for the FAIR anti-proton program. For the commissioning of the pLinac a movable beam diagnostics test bench will be used to characterize the proton beam at different locations during the stepwise installation. The test bench will consist of all relevant types of diagnostic devices as BPM’s, ACCT’s, SEM grids, a slit-grid emittance device and a bunch shape monitor. Moreover, a magnetic spectrometer is supposed to measure the energy spread of the proton beam. Point-to-point imaging is foreseen to enable high energy resolution independently on the transverse emittance. Due to the limited space in the accelerator tunnel a special design must be chosen with the inclusion of quadrupole magnets. The present contribution gives an overall presentation of the test bench and its devices with a special emphasis on the magnetic spectrometer design.  
DOI • reference for this paper ※  
About • paper received ※ 04 September 2019       paper accepted ※ 09 September 2019       issue date ※ 10 November 2019  
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Screen materials for high precision measurements  
  • B. Walasek-Höhne, P. Forck
    GSI, Darmstadt, Germany
  • R. Ischebeck
    PSI, Villigen PSI, Switzerland
  • G. Kube
    DESY, Hamburg, Germany
  Funding: This project has received funding from the European Union’s Horizon 2020 programme under Grant Agreement No 730871.
Scintillation screens made of various inorganic materials are widely used for transverse beam profile diagnostics at all kinds of accelerators. The monitor principle is based on the particles’ energy loss and its conversion to visible light. The resulting light spot is a direct image of the two-dimensional beam distribution. For large beam sizes standard optical techniques can be applied, while for small beam sizes dedicated optical arrangements have to be used to prevent for image deformations. In the modern linac based light sources scintillator usage serves as an alternative way to overcome limitations related to coherent OTR emission. Radiation damages and intensity based saturation effects, in dependence of the screen material, have to be modelled. In this talk, an introduction to the scintillation mechanism in inorganic materials will be given including practical demands and limitations. An overview on actual applications at hadron and electron accelerators will be discussed as summary of the Joint ARIES-ADA Workshop on ’Scintillation Screens and Optical Technology for transverse Profile Measurements’ held in Kraków, Poland.
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TUCO04 Longitudinal Phase Space Reconstruction for the Heavy Ion Accelerator HELIAC 261
  • S. Lauber, K. Aulenbacher, W.A. Barth, C. Burandt, F.D. Dziuba, V. Gettmann, T. Kürzeder, J. List, M. Miski-Oglu
    HIM, Mainz, Germany
  • K. Aulenbacher, W.A. Barth, C. Burandt, F.D. Dziuba, P. Forck, V. Gettmann, M. Heilmann, T. Kürzeder, S. Lauber, J. List, M. Miski-Oglu, A. Rubin, T. Sieber, S. Yaramyshev
    GSI, Darmstadt, Germany
  • K. Aulenbacher
    KPH, Mainz, Germany
  • F.D. Dziuba, S. Lauber, J. List
    IKP, Mainz, Germany
  • H. Podlech, M. Schwarz
    IAP, Frankfurt am Main, Germany
  At the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt, Germany, a prototype cryomodule (Advanced Demonstrator) for the superconducting (SC) continuous wave (CW) Helmholtz Linear Accelerator (HELIAC) is under construction. A transport line, comprising quadrupole lenses, rebuncher cavities, beam correctors and sufficient beam instrumentation has been built to deliver the beam from the GSI 1.4 MeV/u High Charge Injector (HLI) to the Advanced Demonstrator, which offers a test environment for SC CW multigap cavities. In order to achieve proper phase space matching, the beam from the HLI must be characterized in detail. In a dedicated machine experiment the bunch shape has been measured with a non destructive bunch shape monitor (BSM). The BSM offers a sufficient spatial resolution to use it for reconstruction of the energy spread. Therefore, different bunch projections were obtained by altering the voltage of two rebunchers. These measurements were combined with dedicated beam dynamics simulations using the particle tracking code Dynamion. The longitudinal bunch shape and density distribution at the beginning of the matching line could be fully characterized.  
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DOI • reference for this paper ※  
About • paper received ※ 30 August 2019       paper accepted ※ 08 September 2019       issue date ※ 10 November 2019  
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