MEASUREMENT OF THE LONGITUDINAL PHASE SPACE AT THE PHOTO INJECTOR TEST FACILITY AT DESY ZEUTHEN

A setup for the measurement of the longitudinal phase space at the photo injector test facility at DESY Zeuthen is described. The energy of the electrons will reach about 4-5 MeV. The setup includes a Cherenkov radiator which is used to convert the electron beam into a photon beam with a wavelength in the visible range. The Cherenkov ra-diation mechanism is used in order to measure the bunch length with good time resolution. As radiators silica aero-gel with low refractive index as well as a fused silica plate will be used. The time dependent behavior and the position of the photon bunch will be measured by a streak camera system. A simultaneous measurement of the bunch length and the momentum spread will provide the full information about the longitudinal phase space. The design consider-ations of the radiators and their properties are discussed. Preliminary results of the momentum spread taken with a YAG screen are shown.