Characterization of the Analyzing Target of the PEPPo Experiment

The purpose of the PEPPO experiment is to demonstrate, for the first time, the production of polarized positrons from a polarized electron beam. The experiment was performed in Spring 2012 at the CEBAF injector of Jefferson Laboratory (JLab) using a highly spin polarized electron beam. The positron polarization was measured by means of a Compton transmission polarimeter. This work discuss the experimental set up with a special emphasis on the analyzing magnet constituting the polarization filter of the experiment. The knowledge of the analyzing target polarization is discussed on the basis of simulations and calibrated to experimental data.