A real-time sorting algorithm for in-beam PET of heavy-ion cancer therapy device

A real-time digital time-stamp sorting algorithm used in the In-Beam positron emission tomography (In-Beam PET) is presented. The algorithm is operated in the field programmable gate array (FPGA) and a small amount of registers, MUX and memory cells are used. It is developed for sorting the data of annihilation event from front-end circuits, so as to identify the coincidence events efficiently in a large amount of data. In the In-Beam PET, each annihilation event is detected by the detector array and digitized by the analog to digital converter (ADC) in Data Acquisition Unit (DAQU), with a resolution of 14 bits and sampling rate of 50 MS/s. Test and preliminary operation have been implemented, it can perform a sorting operation under the event count rate up to 1 MHz per channel, and support four channels in total, count rate up to 4 MHz. The performance of this algorithm has been verified by pulse generator and Na-22 radiation source, which can sort the events with chaotic order into chronological order completely. The application of this algorithm provides not only an efficient solution for selection of coincidence events, but also a design of electronic circuit with a small-scale structure. (C) 2021 Korean Nuclear Society, Published by Elsevier Korea LLC.

Automated summary

An algorithm for real-time digital time-stamp sorting used in In-Beam PET is presented. It efficiently identifies coincidence events in a large amount of data by sorting annihilation event data from front-end circuits. The algorithm has been verified to work under high event count rates and provides a design of electronic circuit with a small-scale structure.