Intense Infrared Scintillation of Liquid Ar-Xe Mixtures

TL;DR

This study reports the discovery of intense infrared emission at 1.18 μm from liquid Ar-Xe mixtures under electron-beam excitation, with potential applications in particle detection and discrimination.

Contribution

It is the first observation of intense IR scintillation in liquid Ar-Xe mixtures, highlighting a new emission wavelength and efficiency for particle detection.

Findings

Maximum IR emission at 10 ppm Xe in liquid Ar

Conversion efficiency of about 1% for electron beam power

No IR emission detected in pure liquid argon at current sensitivity

Abstract

Intense infrared (IR) light emission from liquid Ar-Xe mixtures has been observed using 12 keV electron-beam excitation. The emission peaks at a wavelength of 1.18 $\mu$m and the half-width of the emission band is 0.1 $\mu$m. Maximum intensity has been found for a 10 ppm xenon admixture in liquid argon. The conversion efficiency of electron beam-power to IR-light is about 1% (10000 photons per MeV electron energy deposited). A possible application of this intense IR emission for a new particle discrimination concept in liquid noble gas detectors is discussed. No light emission was found for perfectly purified liquid argon in the wavelength range from 0.5 to 3.5 $\mu$m on the current level of sensitivity.