Radon Removal in XENONnT down to the Solar Neutrino Level

Résumé fourni par la source

The XENONnT experiment has achieved an exceptionally low Rn 222 activity concentration within its inner 5.9 tonne liquid xenon detector of ( 0.90 ± 0.02 stat ± 0.07 syst ) μ Bq kg − 1 , equivalent to about 430 Rn 222 atoms per tonne of xenon. This was achieved by active online radon removal via cryogenic distillation after stringent material selection. The achieved Rn 222 activity concentration is 5 times lower than that in other currently operational multitonne liquid xenon detectors engaged in dark matter searches. This breakthrough enables the pursuit of various rare event searches that lie beyond the confines of the standard model of particle physics, with world-leading sensitivity. The ultralow Rn 222 levels have diminished the radon-induced background rate in the detector to a point where it is for the first time comparable to the solar neutrino-induced background, which is poised to become the primary irreducible background in liquid xenon-based detectors.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.