2020/04/30 by The DarkSide collaboration, C. E. Aalseth, S. Abdelhakim +314 · 1 citation
Physics and Astronomy · #Argon #Atomic and Subatomic Physics Research #Bremsstrahlung #Dark Matter and Cosmic Phenomena #Electroluminescence #Ionization #Light emission #Near-infrared spectroscopy #Neutrino Physics Research #Noble gas #Photomultiplier #Scintillation #astro-ph.IM #hep-ex #physics.ins-det
paper · pdf · doi:10.1140/epjc/s10052-020-08801-2
published as Eur. Phys. J. C (2021) 81: 153 · 26 pages, 22 figures, 3 tables
openalex created_date 2020/04/10 · openalex publication_date 2021/02/01 · arxiv created 2021/02/26 · arxiv updated 2021/03/01 · openalex updated_date 2026/08/06
Abstract Proportional electroluminescence (EL) in noble gases is used in two-phase detectors for dark matter searches to record (in the gas phase) the ionization signal induced by particle scattering in the liquid phase. The “standard” EL mechanism is considered to be due to noble gas excimer emission in the vacuum ultraviolet (VUV). In addition, there are two alternative mechanisms, producing light in the visible and near infrared (NIR) ranges. The first is due to bremsstrahlung of electrons scattered on neutral atoms (“neutral bremsstrahlung”, NBrS). The second, responsible for electron avalanche scintillation in the NIR at higher electric fields, is due to transitions between excited atomic states. In this work, we have for the first time demonstrated two alternative techniques of the optical readout of two-phase argon detectors, in the visible and NIR range, using a silicon photomultiplier matrix and electroluminescence due to either neutral bremsstrahlung or avalanche scintillation. The amplitude yield and position resolution were measured for these readout techniques, which allowed to assess the detection threshold for electron and nuclear recoils in two-phase argon detectors for dark matter searches. To the best of our knowledge, this is the first practical application of the NBrS effect in detection science.