Progress with Xenon Liquid Hole Multipliers

TL;DR

This paper discusses recent progress in the development of Liquid Hole Multipliers, a novel detection concept for noble-liquid time projection chambers that use bubbles and micro-pattern electrodes to detect ionization and scintillation signals.

Contribution

It presents new experimental results comparing different electrode responses in the Liquid Hole Multiplier system, advancing the understanding of its detection capabilities.

Findings

Different electrode types show varied electroluminescence responses.

The bubble-assisted LHM effectively detects ionization electrons and scintillation photons.

Progress towards practical implementation of LHMs is demonstrated.

Abstract

The bubble-assisted Liquid Hole Multiplier (LHM) is a recently-proposed concept for the combined detection of ionization electrons and primary scintillation photons in noble-liquid time projection chambers. The LHM comprises a perforated micro-pattern electrode (e.g. Thick Gas Electron Multiplier - THGEM, or Gas Electron Multiplier - GEM) immersed in the liquid, with a bubble of the noble gas supported underneath. Ionization electrons and scintillation-induced photoelectrons extracted from a cesium iodide photocathode drift through the electrode's holes and induce electroluminescence (EL) signals in the bubble; these are recorded by photon detectors located closely below the electrode. We present recent results in the development of LHMs, comparing the response of different electrodes to ionization and photon-induced electrons.