Simulation and Assessment of Readout Electronics for Scintillation Light in Liquid Xenon for Nuclear Medical Imaging Systems

¹ Interdisciplinary Institute for Technological Innovation - 3iT, Université de Sherbrooke, Canada
² Subatech, IMT-Atlantique CNRS / IN2P3, Université de Nantes, France

^* e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Published online: 3 August 2026

Abstract

This paper presents the simulation and evaluation of a proposed cryogenic front-end electronics (FEE) system designed to detect scintillation light generated in the XEMIS (Xenon Medical Imaging Systems) application. This nuclear medical imaging modality aims to reduce the injected activity in patients while enhancing spatial resolution by applying a three-gamma imaging technique and employing liquid xenon in time projection chamber (LXe-TPC) as a detector.

This work aims to replace the current FEE, XSRETOT (XEMIS Scintillation Readout for Extraction of Time Over Threshold), in the XEMIS application. The new FEE is designed to facilitate scalability for future iterations, including a full-body version of XEMIS. This system, intended for clinical applications, spans a 2-meter axial length and aims to achieve high detection sensitivity, low power consumption, and cost-effectiveness.

The proposed methodology entailed simulating the replacement of the 30x30 mm² photomultiplier tube with a 4×4 array of VUV-MPPCs (Vacuum Ultraviolet - Multi-Pixel Photon Counters), each measuring 6×6 mm². We assessed three types of FEE for their detection efficiency. Based on the results, we identified the design with a commercial cryogenic transimpedance amplifier and a sigma-delta modulator based on the SiGe HBT technology as the most suitable. The optimized FEE will then be developed and tested at the operating temperature of the LXe-TPC.