A teststand for photo detectors and beamtests for ILC polarimetry

In the future International Linear Collider (ILC) up to 80% polarized electrons shall be brought to collision with up to 60% polarized positrons. Because the cross sections of the resulting reactions depend sensitively on the beam polarization this must be measured with a hitherto never reached accuracy of ΔP/P∼0.25%. This shall be reached via Compton scattering of laser photons from the beam particles and subsequent detection of the scattered electrons in a Cherenkov hodoscope. Content of this thesis was to build a teststand, in which different photodetectors for the detection of the Cherenkov light can be characterized and checked on their suitability for the special application in the ILC polarimeter. The until now best polarization measurement was reached in the framework of the SLD experiment at SLAC in California (ΔP/P∼0.5%). At present the Cherenkov counter of the SLD polarimeter is at DESY and is their used in order to measure different photodetectors coming into question for the ILC polarimetry in the test beam. In order to be able to continue the experiences from the SLD experiment in the framework of this thesis test-beam measurements at the Cherenkov detector are evaluated and the first developments towards a polarimeter for the ILC described