Hybrid Multi Micropattern Gaseous Photomultiplier for detection of liquid-xenon scintillation

TL;DR

This paper demonstrates a hybrid gaseous photomultiplier with high gain for detecting liquid-xenon scintillation, showing promising results for large noble-liquid detectors in medical imaging and dark matter research.

Contribution

It introduces a novel hybrid GPM combining three micropattern structures and characterizes its performance in noble gas mixtures at cryogenic temperatures.

Findings

Achieved gain close to 10^7 in Ne/CF4 mixture.

Operated effectively at room and cryogenic temperatures.

Presented initial results with and without photocathodes.

Abstract

Gaseous PhotoMultipliers (GPM) are a very promising alternative of vacuum PMTs especially for large-size noble-liquid detectors in the field of Functional Nuclear Medical Imaging and Direct Dark Matter Detection. We present recent characterization results of a Hybrid-GPM made of three Micropattern Gaseous Structures; a Thick Gaseous Electron Multiplier (THGEM), a Parallel Ionization Multiplier (PIM) and a MICROMesh GAseous Structure (MICROMEGAS),operating in Ne/CF4 (90:10). Gain values close to 10^7 were recorded in this mixture, with 5.9keV x-rays at 1100 mbar, both at room temperature and at that of liquid xenon (T = 171K). The results are discussed in term of scintillation detection. While the present multiplier was investigated without photocathode, complementary results of photoextraction from CsI UV photocathodes are presented in Ne/CH4 (95:5) and CH4 in cryogenic conditions.