Micromegas-TPC operation at high pressure in Xenon-trimethylamine mixtures

Abstract

We present in this work measurements performed with a small Micromegas-TPC using a xenon-trimethylamine (Xe-TMA) Penning-mixture as filling gas. Measurements of gas gain and energy resolutions for 22.1 keV X-rays are presented, spanning several TMA concentrations and pressures between 1 and 10 bar. Across this pressure range, the best energy resolution and largest increase in gain at constant field (a standard figure for characterizing Penning-like energy transfers) is observed to be in the 1.5%-2.5% TMA region. A gain increase (at constant field) up to a factor 100 and a best energy resolution improved by up to a factor 3 with respect to the one previously reported in pure Xe -operated Micromegas, can be obtained. In virtue of the VUV-quenching properties of the mixture, the overall maximum gain achievable is also notably increased (up to 400 at 10bar), a factor x 3 higher than in pure Xe. In addition, preliminary measurements of the electron drift velocity in a modified setup have been performed and show good agreement with the one obtained from Magboltz. These results are of great interest for calorimetric applications in gas Xe TPCs, in particular for the search of the neutrino-less double beta decay of Xe-136.

8 pages, 7 figures, proceeding

References in corpus (7)

• NEXT-100 Technical Design Report (TDR). Executive Summary
• Radiopurity of Micromegas readout planes
• Micromegas-TPC operation at high pressure in xenon-trimethylamine mixtures
• Characterization of microbulk detectors in argon- and neon-based mixtures
• Micromegas operation in high pressure xenon: charge and scintillation readout
• Micromegas readouts for double beta decay searches
• Status of R&D on Micromegas for Rare Event Searches: The T-REX project

Cited by in corpus (4)

• Gaseous and dual-phase time projection chambers for imaging rare processes
• Gaseous time projection chambers for rare event detection: Results from the T-REX project. I. Double beta decay
• Characterization of a medium size Xe/TMA TPC instrumented with microbulk Micromegas, using low-energy $\gamma$-rays
• Lessons from the operation of the "Penning-Fluorescent" TPC and prospects