Status of the polarized source at MAMI

This talks addresses the operation of the polarized source at the Mainz Microtron MAMI. The source is operating with selected photocathodes of modulation doped, uniaxially strained layer photocathodes, which results in an average spin polarization of 80% and a quantum efficiency of typically 2muA/mW. The operative lifetime has been improved by employing a novel activation technique which reduces transmission losses in the vicinity of the cathode. In addition a considerable simplification of the laser system has become possible by improving the power output of laser diode seed lasers so that it is not necessary to employ power amplifier units. It was shown that the potential for increasing the laser power is limited in our setup because of the thermal resistance between cathode and the surrounding electrode.