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Riemann, S.

Paper Title Page
WEPLS045 Study on Low-energy Positron Polarimetry 2475
 
  • A. Schaelicke, K. Laihem, S. Riemann, A. Ushakov
    DESY Zeuthen, Zeuthen
  • R. Dollan, Th. Lohse
    Humboldt University Berlin, Institut für Physik, Berlin
  
  For the design of the International Linear Collider (ILC) a polarised positron source based on a helical undulator system has been proposed. In order to optimise the positron beam, i.e., to ensure high intensity as well as high degree of polarisation, a measurement of the polarisation close to the positron creation point is envisaged. In this contribution methods to determine the positron polarisation at low energies are investigated. These studies are based on simulations with an extended version of Geant4, which allows the tracking of polarised particles taking into account the spin effects.  
WEPLS046 Radiation Levels and Activation at the ILC Positron Source 2478
 
  • A. Ushakov, S. Riemann
    DESY Zeuthen, Zeuthen
  • Eckhard. Elsen, K. Floettmann
    DESY, Hamburg
  • K.N. Sanosyan
    CANDLE, Yerevan
  
  An undulator-based positron source is recommended as baseline design for the International Linear Collider (ILC). Photons generated by electrons passing an undulator hit a rotating target and create electron-positron pairs. The positrons are captured and accelerated. An advantage of this source is the significantly lower radiation level in comparison to a conventional positron source which uses the electron beam directly to produce electron-positron pairs. The fluxes of neutrons and photons have been calculated with the particle transport code FLUKA. The activation of the positron source components has been estimated depending on the parameters of the source. The results for undulator-based and conventional positron sources are compared and presented.  
THPLS103 Investigations of the Longitudinal Phase Space at PITZ 3517
 
  • J.R. Roensch, J. Rossbach
    Uni HH, Hamburg
  • K. Abrahamyan, G. Asova, J.W. Baehr, G. Dimitrov, H.-J. Grabosch, J.H. Han, O. Kalekin, S. Khodyachykh, S.A. Korepanov, M. Krasilnikov, V. Miltchev, A. Oppelt, B. Petrosyan, S. Riemann, L. Staykov, F. Stephan
    DESY Zeuthen, Zeuthen
  • D. Lipka, R. Richter
    BESSY GmbH, Berlin
  
  The correlation between the positions of the particles in the bunch and their longitudinal momenta has to be analysed in order to optimize photo injectors for Free-Electron Lasers (FELs). Longitudinal phase space measurements at the upgraded PITZ facility* will be presented in this paper. Measurements of the complete longitudinal phase space and its projections behind the gun are compared with simulations. Momentum measurements after a booster cavity will be discussed.

*A.Oppelt et al. "Status and first results from the upgraded PITZ facility", FEL Conf. 2005.