Fast and compact lead tungstate based electromagnetic calorimeter for the PANDA detector at GSI

Experiments with a cooled antiproton beam at the future accelerator facility at GSI, Darmstadt, will be performed with the 4π detector PANDA comprising a high resolution, compact and fast homogeneous electromagnetic calorimeter to detect photons between 10MeV and 10GeV energy inside a superconducting solenoid (2T). PbWO₄ crystals, read-out with large size avalanche photodiodes, represent the most probable detector concept First results of a new generation of significantly improved PbWO₄ crystals, operated at different temperatures, are presented and discussed in detail. The requirements for the photo sensor are outlined based on first test measurements. A new fast hybrid photomultiplier (PLANACON 85001-501, BURLS) with channel plate amplification was investigated for comparison.