Operation of a double-phase pure argon Large Electron Multiplier Time Projection Chamber: comparison of single and double phase operation

TL;DR

This paper reports on the construction and operation of a double phase argon LEM-TPC with a 10x10 cm² area and 30 cm drift, demonstrating its potential for large-scale neutrino and dark matter detection.

Contribution

It introduces a novel double phase argon LEM-TPC design with a segmented anode for 3D imaging, advancing the development of large, cost-effective detectors.

Findings

Successful operation of a 10x10 cm² LAr LEM-TPC

Detection of cosmic muon tracks in double phase mode

Proof of principle for large-scale neutrino and dark matter detectors

Abstract

We constructed and operated a double phase (liquid-vapour) pure argon Large Electron Multiplier Time Projection Chamber (LAr LEM-TPC) with a sensitive area of 10x10 cm$^2$ and up to 30 cm of drift length. The LEM is a macroscopic hole electron multiplier built with standard PCB techniques: drifting electrons are extracted from the liquid to the vapour phase and driven into the holes of the LEM where the multiplication occurs. Moving charges induce a signal on the anode and on the LEM electrodes. The orthogonally segmented upper face of the upper LEM and anode permit the reconstruction of X-Y spatial coordinates of ionizing events. The detector is equipped with a Photo Multiplier Tube immersed in liquid for triggering the ionizing events and an argon purification circuit to ensure long drift paths. Cosmic muon tracks have been recorded and further characterization of the detector is ongoing. We believe that this proof of principle represents an important milestone in the realization of very large, long drift (cost-effective) LAr detectors for next generation neutrino physics and proton decay experiments, as well as for direct search of Dark Matter with imaging devices.