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

Understand

In this work we present a systematic study of Micromegas detectors in high pressure gaseous Xenon using trimethylamine (TMA) as quencher gas.

• Gas gains and energy resolutions for 22.1 keV X-rays are measured for pressures between 1 and 10 bar and various relative concentrations of TMA from 0.3 % to 15 %.
• We observe stable operation at all pressures, and a strongly enhanced gas gain, suggestive of Penning-like energy-transfer processes.
• The effect is present at all pressures and it is strongest at TMA concentrations ranging from 1.5 % to 3 %.