Author: Koop, R.
Paper Title Page
MOPMB010 Compton Polarimetry at ELSA - Beamline and Detector Optimization 95
  • R. Koop, W. Hillert, M.T. Switka
    ELSA, Bonn, Germany
  Funding: Work supported by DFG within CRC TRR16
The Electron Stretcher Facility ELSA provides a polarized electron beam with energies of 0.5 - 3.2 GeV for double polarization hadron physics experiments. Monitoring the vertical electron polarization by Compton polarimetry in the stretcher ring has several advantages over the established polarization measurement by Moeller polarimetry. The Compton polarimeter setup presented consists of a 40 W cw disk laser featuring two polarized photon beams colliding head-on with the stored electron beam in ELSA. A silicon strip detector measures the vertical intensity profile of the backscattered photons. The reversal of handedness of the laser beam's circular polarization results in a polarization dependent vertical shift of this profile. From a calibration using time dependent polarization build-up due to the Sokolov-Ternov effect, the polarization degree of the electron beam can be extracted. After recent laser repairs as well as beamline and detector modifications, first measurement attempts of the electron's polarization degree were conducted. The performance of the beamline and first measurements are presented.
DOI • reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB010  
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