Study of a sealed high gas pressure THGEM detector and response of Alpha particle spectra

TL;DR

This study investigates a sealed high-pressure argon detector with a THGEM, analyzing its response to alpha particles and how gas pressure affects spectral shape and gain, validated by experiments and simulations.

Contribution

It presents a novel sealed high-pressure THGEM detector and explores its performance and spectral response under varying pressures, including experimental and simulation validation.

Findings

Gas gain normalized by $E/P$ matches theoretical predictions.

Good airtightness confirmed by barometer and gas gain measurements.

Spectral shape depends on gas pressure, affecting detector response.

Abstract

A sealed high gas pressure detector working in pure argon is assembled. It consists of a 5 cm $\times$ 5 cm PCB THGEM (THick Gaseous Electron Multipliers). The detector structure and experimental setup are described. The performances under high pressure of 2 atm mainly consist in selecting optimal voltages for ionization region and induction region. The dependence of the shape of Alpha particle spectra measured with relative gas gain on gas pressure (1.3 $\sim$ 2.0 atm) has been studied. The 8 groups of relative gas gain versus working voltage of THGEM expressed by weighting filed $E/P$ are normalized, being consistent with theory. The results show that the air tightness of the chamber is good measured by a sensitive barometer and checked with gas gain. The experimental results are compared with Monte Carlo simulation on energy deposition without gas gain involved.