Eur. Phys. J. Plus (2020) 135: 14
https://doi.org/10.1140/epjp/s13360-019-00034-x

Regular Article

Time resolution of a scintillator–photodetector assembly

¹ INFN Bari, Via E. Orabona 4, 70125, Bari, Italy
² INFN Lecce, Via Arnesano, 73100, Lecce, Italy

^* e-mail: roberto.perrino@le.infn.it

Received: 22 May 2019
Accepted: 23 September 2019
Published online: 7 January 2020

Abstract

The accurate understanding and control of the time resolution of a scintillator–photodetector assembly are becoming more and more important in medical physics. The time-of-flight information in the positron emission tomography (TOF-PET) enhances in fact the signal-to-noise ratio of the reconstructed images. We present a custom-made Monte Carlo code investigating the role of all the parameters contributing to the time resolution. In particular, the single photoelectron response barely affects the best achievable time resolution. However, it plays a dominant role in reproducing the shape and features (rise time, amplitude) of the signal produced by the detection of a gamma ray. In such a way, it mostly determines the threshold for the best time resolution. We validated the Monte Carlo code by comparing its results with available measurements of time resolutions at various threshold levels in assemblies formed by small-size L(Y)SO and LuAG crystals coupled to Silicon photomultipliers (SiPM) and photomultiplier tubes (PMT).