Operation of gas electron multipliers in pure xenon at low temperatures

Operation of Gas Electron Multiplier (GEM) in ultra-pure xenon was studied for gas at 25 °C, cold but not saturated gas at −90 °C and saturated xenon vapour at −102 °C. The most stable operation was observed at −90 °C for which the maximum visible gain of 150 was obtained from a single GEM. The maximum gain of ≈40 was achieved for saturated xenon vapour at −102 °C and of ≈25 for two-phase configuration at the same temperature. Continuous operation of a GEM in two-phase mode for periods of several hours was routinely achieved.