Development and Test of a SiPM Array Readout Module for High Performance Calorimeters

SiPM photodetectors present significant advantages over photomultipliers for the design of radiation detectors for high energy physics and nuclear physics detectors. We present a readout design proposed for the PWO detectors of the Electron Ion Collider where high magnetic fields preclude the use of vacuum PMTs. The readout includes a 4 x 4 SiPM array directly coupled to a preamplification and summation stage. The low capacitance input feeds a second amplification stage with adjustable gain and offset. A power supply and communication board with eeprom to store the amplifier settings and with a temperature compensation loop to stabilize the device gain also includes a USB port to complete the electronic design. The compact and low power circuit was optimized for fast signal acquisition to meet the 100 – 200 ns digitization gate requirements. A detector prototype was constructed with a 3 x 3 array of 20 x 20 x 200 mm PWO crystals, each coupled to a separate readout circuit. This detector was tested at the Thomas Jefferson National Accelerator Facility with 4.5GeV and 5.8 GEV positrons. We will present the results of these tests including the spectral resolution performance and the signal timing achievements. We will discuss the analysis of the performance and projected improvements on the stochastic term using different SiPMs. We will discuss the impact on response linearity, dynamic range, and possible compensation of detrimental effects. We will discuss the optimization of the design to minimize the constant term in the spectral resolution behavior as a function of energy and plans for the next prototype build.