Author: Kowina, P.
Paper Title Page
MOPC21 Layout of the BPM System for p-LINAC at FAIR and the Digital Methods for Beam Position and Phase Monitoring 101
  • M.H. Almalki, G. Clemente, P. Forck, L. Groening, W. Kaufmann, P. Kowina, C. Krüger, R. Singh
    GSI, Darmstadt, Germany
  • W. Ackermann
    TEMF, TU Darmstadt, Darmstadt, Germany
  • M.H. Almalki
    IAP, Frankfurt am Main, Germany
  • M.H. Almalki
    KACST, Riyadh, Kingdom of Saudi Arabia
  • B.B. Baricevic, R. Hrovatin, P.L. Lemut, M. Znidarcic
    I-Tech, Solkan, Slovenia
  • C.S. Simon
    CEA/DSM/IRFU, France
  The planned Proton LINAC at the FAIR facility will provide a beam current from 35 to 70 mA accelerated to 70 MeV by novel CH-type DTLs. Four-fold button Beam Position Monitor (BPM) will be installed at 14 locations along the LINAC and some of these BPMs are mounted only about 40 mm upstream of the CH cavities. The coupling of the RF accelerating field to the BPMs installed close to the CH cavities was numerically investigated. For the digital signal processing using I/Q demodulation a 'Libera Single Pass H' is foreseen. The properties of this digitization and processing scheme were characterized by detailed lab-based tests. Moreover, the performance was investigated by a 80 μA Ne4+ beam at 1.4 MeV / u and compared to a time-domain approach and successive FFT calculation. In particular, concerning the phase determination significant deviations between the methods were observed and further investigations to understand the reason are ongoing.  
poster icon Poster MOPC21 [1.622 MB]  
MOPC36 Test of a Non-Invasive Bunch Shape Monitor at GSI High Current LINAC 151
  • P. Forck, C. Dorn, O.K. Kester, P. Kowina, B. Zwicker
    GSI, Darmstadt, Germany
  • O.K. Kester
    IAP, Frankfurt am Main, Germany
  Funding: The work is funded by European Union FP7 within CRISP.
At the heavy ion LINAC at GSI, a novel scheme of non-invasive Bunch Shape Monitor has been tested with several ion beams at 11.4 MeV/u. The monitor’s principle is based on the analysis of secondary electrons as liberated from the residual gas by the beam impact. These electrons are accelerated by an electrostatic field, transported through a sophisticated electrostatic energy analyzer and an RF-deflector, acting as a time-to-space converter. Finally a MCP amplifies electrons and with a CCD camera the electron distribution is detected. For the applied beam settings this Bunch Shape Monitor is able to obtain longitudinal profiles down to a width of 400 ps with a resolution of 50 ps, corresponding to 2 degree of the 108 MHz accelerating frequency. Systematic parameter studies for the device were performed to demonstrate the applicability and to determine its resolution. The achievements and ongoing improvements for the monitor are discussed.
poster icon Poster MOPC36 [2.665 MB]  
TUPF30 Measurements with the Upgraded Cryogenic Current Comparator 583
  • F. Kurian, P. Hülsmann, P. Kowina, H. Reeg, M. Schwickert
    GSI, Darmstadt, Germany
  • R. Geithner, R. Neubert, W. Vodel
    FSU Jena, Jena, Germany
  • R. Geithner, W. Vodel
    HIJ, Jena, Germany
  Funding: HGS-HiRe for FAIR
For the measurement of the very low ion beam current -down to nA range- foreseen in the High Energy Transport sections of the upcoming FAIR facility, an improved Cryogenic Current Comparator (CCC) is under development at GSI. The existing CCC unit, initially operated at the high energy beam transport section after the GSI synchrotron SIS18, has been upgraded as a prototype for FAIR. The upgraded CCC is presently being re-commissioned. In this contribution we report on beam current measurements with the improved detector unit down to 5 nA simulated by a wire loop wound around the magnetic sensor. As mechanical vibrations strongly influence the sensitive SQUID detector, vibration analyses have been carried out using an accelerometer. Noise contributions from various mechanical as well as electrical sources were studied and the achieved detector performance is presented
poster icon Poster TUPF30 [1.702 MB]  
THAL1 Understanding the Tune Spectrum of High Intensity Beams 914
  • R. Singh, O. Chorniy, P. Forck, R. Haseitl, W. Kaufmann, P. Kowina, K. Lang
    GSI, Darmstadt, Germany
  • R. Singh
    TEMF, TU Darmstadt, Darmstadt, Germany
  Tune spectra measurements are routinely performed in most synchrotrons. At high intensity and low energies (i.e. γ≈1), space charge effects can significantly modify the tune spectra in comparison to the classical low intensity spectra. Systematic studies were performed at GSI SIS-18 to observe these characteristic modifications, mainly resulting from the shift of the head-tail modes in direct dependence of beam intensity and synchrotron tune frequency. In this contribution, an interpretation of the tune spectra modification based on quasi-analytical models and numerical simulations will be presented. Extraction of elusive beam parameters such as incoherent tune shift, machine impedances, chromaticity, etc. from the spectra will be demonstrated. Further, the applications and relevance of these results for other synchrotrons will be discussed.  
slides icon Slides THAL1 [3.807 MB]