Author: Kaufmann, W.
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]  
WEPF35 Current Status of the Schottky Cavity Sensor for the CR at FAIR 907
  • M. Hansli, R. Jakoby, A. Penirschke
    TU Darmstadt, Darmstadt, Germany
  • P. Hülsmann, W. Kaufmann
    GSI, Darmstadt, Germany
  Funding: This work was supported by the GSI. The author would like to thank the CST AG for providing CST Studio Suite.
In this paper the current status of the Schottky Cavity Sensor development for the Collector Ring at FAIR, a dedicated storage ring for secondary particles, rare isotopes, and antiprotons, is presented. Designed for longitudinal and transversal Schottky signals, the Sensor features a pillbox cavity with attached waveguide filters utilizing the Monopole mode at 200 MHz for longitudinal and the Dipole mode at around 330 MHz for transversal Schottky measurements. Separated coupling structures allow for mode-selective coupling to measure the different Schottky planes independently. A ceramic vacuum shielding inside the pillbox is implemented to enable non-hermetic adjustable coupling, tuning devices and waveguide structures. Simulations of the structure with focus on the impact of the coupling structures and the ceramic vacuum shielding on the R-over-Q values and the coupling are presented as well as measurements of a scaled demonstrator including comparisons with the simulations.
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]