Performance characteristics of a new generation of processing circuits for PET applications

An electronics architecture for a PET tomograph is presented which utilizes a newly developed ASIC CFD and TDC to fully utilize the timing advantages of an LSO scintillation crystal. Intrinsic timing resolution for LSO against plastic has been measured at 900 ps FWHM using the ASIC CFDs and TDCs for both channels. The energy and pixel location are derived using continuous sampling ADCs with FPGA digital processing algorithms. Digitally converted PMT signals are modified using dynamic TDC values to recalibrate the energy and position since the sampling frequency is unrelated to the event data. The linearity of the energy channels is 1.8% for a 6:1 input dynamic range.