Synchronisation and calibration of the 24-modules J-PET prototype with 300~mm axial field of view

TL;DR

This paper presents the development and calibration of a 24-module J-PET prototype with a 300mm axial field-of-view, demonstrating promising results for cost-effective total-body PET imaging.

Contribution

It introduces new calibration methods for a digital, triggerless data acquisition system in a plastic scintillator-based PET prototype.

Findings

Achieved coincidence resolving time of 490 ps

Position reconstruction accuracy of 18 mm

Successful calibration of time, thresholds, and gain

Abstract

Research conducted in the framework of the J-PET project aims to develop a cost-effective total-body positron emission tomography scanner. As a first step on the way to construct a full-scale J-PET tomograph from long strips of plastic scintillators, a 24-strip prototype was built and tested. The prototype consists of detection modules arranged axially forming a cylindrical diagnostic chamber with the inner diameter of 360 mm and the axial field-of-view of 300 mm. Promising perspectives for a low-cost construction of a total-body PET scanner are opened due to an axial arrangement of strips of plastic scintillators, wchich have a small light attenuation, superior timing properties, and the possibility of cost-effective increase of the axial field-of-view. The presented prototype comprises dedicated solely digital front-end electronic circuits and a triggerless data acquisition system which required development of new calibration methods including time, thresholds and gain synchronization. The system and elaborated calibration methods including first results of the 24-module J-PET prototype are presented and discussed. The achieved coincidence resolving time equals to CRT = 490 $\pm$ 9 ps. This value can be translated to the position reconstruction accuracy $\sigma(\Delta l) =$ 18 mm which is fairly position-independent.