A fast and compact electromagnetic calorimeter for the PANDA detector at GSI

PANDA is a 4π detector planned for the antiproton storage ring at the proposed International Accelerator Facility for Beams of Ions and Antiprotons at the GSI. Experiments foreseen with the antiproton beam of extremely high luminosity and excellent beam quality up to 15 GeV/c beam momentum require an electromagnetic calorimeter of high granularity and resolution to measure photons of several GeV down to 10 MeV energy. The scintillator materials being investigated for this calorimeter are BGO and new improved PbWO4 crystals. For the detection of the scintillation light Avalanche Photo Diodes are being tested. The concept of the calorimeter as well as initial results from the R&D program are presented.