Bubble-assisted Liquid Hole Multipliers in LXe and LAr: towards "local dual-phase TPCs"

TL;DR

This paper introduces a novel bubble-assisted Liquid Hole Multiplier (LHM) concept for combined ionization and scintillation detection in noble-liquid TPCs, demonstrating its principles and initial results in LXe and LAr.

Contribution

It presents the design and basic principles of the LHM, a new approach for dual-phase noble-liquid detectors, with initial experimental results in LXe and LAr.

Findings

Successful demonstration of electroluminescence in LXe and LAr

Potential for improved event localization in noble-liquid TPCs

Feasibility of using bubble-assisted LHMs for dual-phase detection

Abstract

The bubble-assisted Liquid Hole Multiplier (LHM) is a novel concept for the combined detection of ionization electrons and scintillation photons in noble-liquid time projection chambers. It consists of a perforated electrode immersed in the noble liquid, with heating wires generating a stable bubble underneath. Radiation-inducted ionization electrons in the liquid drift into the electrode's holes and cross the liquid-vapor interface into the bubble where they induce electroluminescence (EL). The top surface of the electrode is optionally coated with a CsI photocathode; radiation-induced UV-scintillation photons extract photoelectrons that induce EL in a similar way. EL-photons recorded with an array of photosensors, e.g. SiPMs, provide event localization. We present the basic principles of the LHM and summarize the results obtained in LXe and LAr.