TRANSVERSE EMITTANCE MEASUREMENTS AT THE PHOTO INJECTOR TEST FACILITY AT DESY ZEUTHEN (PITZ)

-The distance between the slits is a compromise between obtaining a good representation of the phase space and avoiding overlapping of the beamlets The components and functionality of the emittance measurement system at PITZ are introduced. In brief some design considerations are reviewed as well. The influence of the noise due to dark current and electronic noise in beam size measurements is discussed and estimated. Results from recent transverse emittance measurements are presented and compared with simulations. Examples of a strongly distorted trace space are also considered where the application of a single slit scanning technique is a successful alternative of the multi-slit method. -The contribution of the initial beamlet size to the beamlet size at the observation screen should be as small as possible -The thickness of the mask is a compromise between the need to scatter electrons to form a uniform background and the desire to minimize the slit-edge scattering. The masks are installed on the two actuators in the following arrangement: on the vertical actuator a multislit mask, a pepper-pot mask and a single slit mask are mounted. On the horizontal one: multi-slit mask, singleslit mask and YAG screen for direct observation of the electron beam.