Readout Electronics for the Zero Degree Calorimeter at HIRFL-CEE Experiment

Abstract

The CSR External-target Experiment (CEE) at the Heavy Ion Research Facility at Lanzhou (HIRFL) will be the first GeV large-scale nuclear physics experiment developed independently in China. The primary physics goal of the CEE is to study the nuclear equation of state, hyper nuclei, and radioactive ion beam physics. The Zero Degree Calorimeter (ZDC) of CEE measures the centrality and reaction plane of the nuclear-nuclear collision relative to the hadron background. It consists of 192 roughly trapezoidal Plastic Scintillator (PS) crystal blocks coupled with PMT (Photo Multiplier Tube) to convert charged particles into electrical signals. The readout electronics consists of 12 FEE (Front End Electronics), the sub-trigger module, and the sub-clock module. In addition, one HV (High Voltage) crate provides a high voltage power supply for the PMTs. According to the electrical test on the electronics, the RMS (Root Mean Square) noise is less than 0.4 mV, and the nonlinearity is less than 0.06%. The heavy-ion beam test shows that the ZDC can measure particles up to Z=7, which meets the physics requirements.