Design and implementation of simplified readout circuits for multi-anode Position-Sensitive Photomultiplier Tubes
The multi-anode position sensitive photomultiplier tube(PSPMT) has been used for the development of high-resolution γ camera module. This study is aimed to investigate the simplified readout design for the multi-anode flat panel PSPMT. Based on the Hamamatsu H8500 PSPMT with 64 multi-anodes, we designed and developed two simplified readout circuits, discretized positioning circuit(DPC) and symmetric charge division circuit(SCDC). The truncated center-of-gravity(TCOG) positioning method was used to optimize the readout signal processing and then further reduce the readout channels by a resistor chain. The preliminary results show that the SCDC readout with the TCOG could significantly reduce the non-linearity of positioning and improve the effective field-of-view of the detector by about 20% as compared to the DPC readout.