Preliminary assessment of a new data acquisition system for the microPET at IFUNAM

In this work the new data acquisition system (DAQ) for the microPET of the SIBI project is presented. To increase the microPET sensitivity, the inclusion of more detection modules is required, which in turn needs a more sophisticated and compact signal processing system. The new DAQ is based on programmable integrated circuits (FPGAs) and is composed of (i) an 8-input triggering board with individual channel adjusting capabilities, which can process signals from 8 detector modules working in coincidence mode and (ii) two 10-channel digitising boards with 12-bit resolution. The digitised signals are transmitted to a PC through two Ethernet ports in each board. With the new boards the maximum singles counting rate is of the order of 350 kHz, with a dead time of 2.8 mu s. Individual crystal maps of two detectors for image corrections have been obtained, with peak-to-valley ratios of 5:1. The new FPGA boards will allow the introduction of more detection modules with relatively simple electronics arrangement.