The BGO Electromagnetic Calorimeter Sub-trigger Electronics for DAMPE

The Dark Matter Particle Explorer (DAMPE) is being constructed as a scientific satellite to observe high energy cosmic rays in space. As a main sub-detector of DAMPE, the BGO electromagnetic calorimeter provides a wide measurement range of energy deposition of the particles traversing the detector and generates trigger information for the trigger selection module. There are 704 photomultiplier tube (PMT) dynode signals in total to generate the sub-trigger signals, which bring difficulties in design of the front end electronics (FEE) on the space-limited and power-limited satellite platform. To overcome the challenge, a front end ASIC chip, VATA160, which integrates 32 charge measurement channels with trigger, is adopted. There are 32 VATA160 chips mounted on 8 FEE-A boards for calorimeter. A performance test setup and a PMT calibration setup are built to evaluate the FEE-A board. The test results of RMS noise, linearity, trigger threshold and time walk effect are shown.