First evidence of luminescence in a He/CF$_4$ gas mixture induced by non-ionizing electrons

Understand

Optical readout of Gas Electron Multipliers (GEM) provides very interesting performances and has been proposed for different applications in particle physics.

• In particular, thanks to its good efficiency in the keV energy range, it is being developed for low-energy and rare event studies, such as Dark Matter search.
• So far, the optical approach exploits the light produced during the avalanche processes in GEM channels.
• Further luminescence in the gas can be induced by electrons accelerated by a suitable electric field.