Photon emission and atomic collision processes in two-phase argon doped with xenon and nitrogen
Budker Institute of Nuclear Physics SB RAS - Novosibirsk, 630090, Russia and Novosibirsk State University - Novosibirsk, 630090, Russia
Received: 7 February 2017
Accepted: 9 March 2017
We present a comprehensive analysis of photon emission and atomic collision processes in two-phase argon doped with xenon and nitrogen. The dopants are aimed to convert the VUV emission of pure Ar to the UV emission of the Xe dopant in the liquid phase and to the near UV emission of the N2 dopant in the gas phase. Such a mixture is relevant to two-phase dark-matter and low-energy neutrino detectors, with enhanced photon collection efficiency for primary- and secondary-scintillation signals. Based on this analysis, we show that the recently proposed hypothesis of the enhancement of the excitation transfer from Ar to N2 species in the two-phase mode is either incorrect or needs assumptions about a new extreme mechanism coming into force at lower temperatures, in particular that of the resonant excitation transfer via the ArN2 compound (van der Waals molecule).
PACS: 95.55.Vj – Neutrino, muon, pion, and other elementary particle detectors; cosmic ray detectors / 61.25.Bi – Liquid noble gases / 95.35.+d – Dark matter (stellar, interstellar, galactic, and cosmological)
© EPLA, 2017