Study on Timing Performance of a Readout Circuit for SiPM

TL;DR

This study investigates the timing performance of a SiPM readout circuit for PET detectors, identifying key factors affecting coincidence time resolution and achieving a 266 ps FWHM CTR after optimization.

Contribution

It introduces a SiPM readout pre-amplifier design with PZ compensation and analyzes factors influencing timing performance in PET detectors.

Findings

CTR is heavily influenced by amplifier bandwidth, SiPM bias voltage, and PZ network parameters.

Optimized readout circuit achieves a 266 ps FWHM CTR.

Guidelines provided for future readout ASIC chip design.

Abstract

In recent years, SiPM photoelectric devices have drawn much attention in the domain of time-of-flight-based positron emission tomography (TOF-PET). Using them to construct PET detectors with excellent coincidence time resolution (CTR) is always one of research focus. In this paper, a SiPM readout pre-amplifier based on common-base current amplifier structure followed by a Pole-Zero (PZ) compensation network is constructed, and the main factors that affect the timing performance of the PET detector are investigated. By experimental measurement, we found that the CTR is heavily related to the bandwidth of the amplifier, bias voltage of SiPM, comparator threshold, and PZ network parameter. The test setup has two detectors, one with LYSO crystal (3 mm 3 mm 10 mm) coupled with a Hamamatsu SiPM (S12642-0404), and the other with LaBr3 coupled to a PMT-R9800. After the optimization of the readout circuit with related factors, the CTR between the two detectors is measured as 266ps FWHM. The test result is a helpful guideline for the readout ASIC chip design in our next step.