First Demonstration of the Use of LG-SiPMs for Optical Readout of a TPC

TL;DR

This paper demonstrates a novel optical readout method for TPCs using LG-SiPMs, showing successful 3D track reconstruction and energy measurement, indicating its potential for advanced particle detection.

Contribution

Introduces the first use of LG-SiPMs for optical TPC readout, enabling precise 3D tracking and energy reconstruction with a new detector technology.

Findings

Successful 3D ionisation track reconstruction

Consistent energy deposition measurements

Feasibility of LG-SiPMs for optical TPC readout

Abstract

This paper describes a new method for optical readout of Time Projection Chambers (TPCs), based on the Linearly Graded Silicon Photomultiplier (LG-SiPM). This is a single photon-sensitive detector with excellent timing and 2D position resolution developed at Fondazione Bruno Kessler, Trento (FBK). The LG-SiPM produces time-varying voltage signals that are used to reconstruct the 3D position and energy of ionisation tracks generated inside the TPC. The TPC used in this work contained room-temperature CF$_4$ gas at a pressure of 100 mbar, with two THGEMs to produce secondary scintillation light. A collimated $^{241}$Am source (Q$_\alpha$ = 5.486 MeV) was used to produce the ionisation tracks. The successful reconstruction of these tracks is demonstrated, and the consistency of the methodology characterised through varying the geometry of the tracks within the TPC. Energy reconstruction and deposition studies are also described, demonstrating the feasibility of the LG-SiPM as a potential option for optical TPC readout.