Design optimization of an emittance measurement system at Pitz

The photo injector test facility at DESY Zeuthen (PITZ) has been built to test and to optimize electron sources for Free Electron Lasers (FELs). In order to study the emittance conservation principle, further acceleration is required. To increase the electron beam energy up to 30 MeV, a booster accelerating cavity is under commissioning. With this upgrade, the projected normalized transverse emittance less than 1 mm mrad is expected from beam dynamics simulations. To measure such small emittance, an upgrade of the existing Emittance Measurement SYstem (EMSY) is required. EMSY uses the slit mask technique to determine the beam emittance. In this paper, considerations on the physics of the system as well as results from GEANT4 simulations are given. The expected signal to noise ratio, the resolution of the system, and the energy deposition in the slit-mask are presented. EMSY is under construction at INRNE Sofia. Installation and first results are expected by the end of this year. (author)