A Moller polarimeter for CW and pulsed intermediate-energy electron beams

The Moller polarimeter was mainly designed for the cw electron beam of the Mainz microtron (MAMI). The described polarimeter covers an energy range between 25 and 185 MeV and can relatively simply be upgraded to the maximum MAMI energy of 840 MeV. The Moller-scattered electrons are momentum-analyzed in the defocusing plane of a quadrupole magnet and both Moller electrons can be detected in coincidence for symmetrical scattering with ⊖cm=90°. All polarization components of the electron beam can be measured by suitable choices of the orientation of the target polarization. For pulsed electron beams with a small duty factor and a high peak current the polarimeter can also be operated with single arm analog detection of the Moller-scattered electrons.