High pressure operation of the Photon-Assisted Cascaded Electron Multiplier

TL;DR

This paper demonstrates high-pressure operation of the Photon Assisted Cascaded Electron Multiplier (PACEM) in xenon, achieving significant optical and total gains, and compares its performance to other electron multipliers.

Contribution

It introduces the operation of PACEM at high pressure and compares its gain performance with existing electron multipliers.

Findings

Optical gain of 10^3 at atmospheric pressure

Optical gain drops to 25 at 3.3 bar pressure

Total gains surpass those of triple GEM and double THGEM

Abstract

We present the operation of the recently introduced Photon Assisted Cascaded Electron Multiplier (PACEM) in xenon at high pressure. The PACEM is a multi step electron multiplier where the VUV scintillation produced in the electron avalanches is used for signal propagation: the VUV scintillation produced in the first element of the cascade induces the emission of photoelectrons from a CsI photocathode placed on the top-surface of the second element. These photoelectrons are further multiplied, via charge avalanche. A metallic mesh electrode placed between the first and the second elements of the cascade completely blocks the charge transfer between them. Optical gains of 103 were achieved in xenon at atmospheric pressure, dropping to 25 at 3.3 bar, for applied voltages of 700 and 1100 V, respectively. Taking into account the subsequent charge multiplication, total gains are higher than those obtained with a triple GEM and double THGEM.