Operation of a LAr-TPC equipped with a multilayer LEM charge readout

B Baibussinov,D Gibin,F Pietropaolo,K Zatrimaylov,A Fava,G Meng,S Centro,S Ventura,F Varanini,A Guglielmi,C Farnese

doi:10.1088/1748-0221/13/03/t03001

Abstract

A novel detector for ionization signals in a single phase LAr-TPC has been experimented in the ICARINO test facility at the INFN Laboratories in Legnaro. It is based on the adoption of a multilayer Large Electron Multiplier (LEM) replacing the traditional anodic wire arrays. Cosmic muon tracks were detected allowing the measurement of energy deposition and a first determination of the signal to noise ratio. The analysis of the recorded events demonstrated the 3D reconstruction capability of this device for ionizing events in liquid Argon. The collected fraction of ionization charge is close to about 90%, with signal to noise ratio similar to that measured with more traditional wire chambers.

Highlights

: A novel detector for ionization signals in a single phase liquid argon (LAr)-TPC has been experimented in the ICARINO test facility at the INFN Laboratories in Legnaro
The whole detector vessel is contained in an open-air stainless steel dewar, which is initially filled with commercial LAr acting as cryogenic bath for the ultra-pure LAr injected in the detector vessel
The successful operations of a LAr-TPC equipped with a multilayer Large Electron Multiplier (LEM) anodic plane proved its feasibility to detect and measure charge signals in the single phase LAr-TPC

Summary

Description of the experimental set up

The ICARINO set-up includes a fully functional small LAr-TPC operated in INFN-LNL for test purposes (figure 1). The liquid argon (LAr) is contained in a stainless steel cylindrical vessel closed by an ultra-high vacuum flange hosting the feed-through for vacuum, LAr filling and re-circulation, high voltage cables and readout electronics. The whole detector vessel is contained in an open-air stainless steel dewar, which is initially filled with commercial LAr acting as cryogenic bath for the ultra-pure LAr injected in the detector vessel. The standard TPC chamber active volume corresponds to 38 kg of active LAr mass, delimited laterally by four 29.4 × 29.4 cm FR4 boards supporting the field-shaping electrodes (30 strips of gold-plated copper) and by two vertical electrode planes, 32.6 × 32.6 cm, acting as cathode and anode (figure 2 left). The experimental setup is complemented by a telescope composed by set of 4 external plastic scintillators for triggering purposes, selecting crossing cosmic muons in 30◦ ÷ 50◦ zenith angle, so that most of the collection view channels and a large fraction of the induction view ones were interested in the event

The multilayer LEM anodic plane

Test with cosmic rays

Conclusions