Puzzling time properties of proportional electroluminescence in two-phase argon detectors for dark matter searches

Abstract

Proportional electroluminescence (EL) in noble gases is a physical process routinely used in two-phase (liquid-gas) detectors for low-energy astroparticle-physics experiments. In this work, the time properties of visible-light EL in two-phase argon detectors have been systematically studied for the first time. In particular, two unusual slow components in the EL signal, with their contributions and time constants increasing with electric field, were observed. This puzzling property is not expected in any of the known mechanisms of photon and electron emission in two-phase media. Time constants of these components is about 4-5 $\mu$s and 50 $\mu$s. In addition, a specific threshold behavior of the slow components was revealed: they emerged at a threshold in reduced electric field of 4.8 $\pm$ 0.2 Td regardless of the gas phase density, which is about 1 Td above the onset of standard (excimer) EL. There is a conspicuous similarity between this threshold and reduced field threshold of EL in NIR occurring via higher atomic excited states Ar${}^{\ast }(3p^{5}4p)$. An unexpected temperature dependence of slow components was also observed: their contribution decreased with temperature, practically disappearing at room temperature. We show that the puzzling properties of slow components can be explained in the framework of hypothesis that these are produced in the charge signal itself due to trapping of drifting electrons on metastable negative argon ions.

arXiv comment13 pages, 18 figures

References in corpus (37)

• Dark Matter Search Results from a One Tonne$\times$Year Exposure of XENON1T
• DarkSide-20k: A 20 Tonne Two-Phase LAr TPC for Direct Dark Matter Detection at LNGS
• Light Dark Matter Search with Ionization Signals in XENON1T
• Excess Electronic Recoil Events in XENON1T
• Low-Mass Dark Matter Search with the DarkSide-50 Experiment
• DarkSide-50 532-day Dark Matter Search with Low-Radioactivity Argon
• Liquid noble gas detectors for low energy particle physics
• Characterization of Three High Efficiency and Blue Sensitive Silicon Photomultipliers
• Emission of Single and Few Electrons in XENON1T and Limits on Light Dark Matter
• Observation and applications of single-electron charge signals in the XENON100 experiment
• Investigation of background electron emission in the LUX detector
• A simulation toolkit for electroluminescence assessment in rare event experiments
• Two distinct components of the delayed single electron background signals in liquid xenon emission detectors
• Revealing neutral bremsstrahlung in two-phase argon electroluminescence
• Measurement of the absolute Quantum Efficiency of Hamamatsu model R11410-10 photomultiplier tubes at low temperatures down to liquid xenon boiling point
• Formation and dynamics of van der Waals molecules in buffer-gas traps
• Electroluminescence and electron avalanching in two-phase detectors
• SiPM-matrix readout of two-phase argon detectors using electroluminescence in the visible and near infrared range
• Infrared scintillation yield in gaseous and liquid argon
• Photon emission and atomic collision processes in two-phase argon doped with xenon and nitrogen
• Neutral Bremsstrahlung emission in xenon unveiled
• Electroluminescence pulse shape and electron diffusion in liquid argon measured in a dual-phase TPC
• Electron emission properties of two-phase argon and argon-nitrogen avalanche detectors
• Ion-beam excitation of liquid argon
• Correlated Single- and Few-Electron Backgrounds Milliseconds after Interactions in Dual-Phase Liquid Xenon Time Projection Chambers
• Two-phase Cryogenic Avalanche Detector with electroluminescence gap operated in argon doped with nitrogen
• Neutral bremsstrahlung electroluminescence in noble liquids
• Characterization of photo-multiplier tubes for the Cryogenic Avalanche Detector
• Electron transport and electric field simulations in two-phase detectors with THGEM electrodes
• Neutral bremsstrahlung and excimer electroluminescence in noble gases and its relevance to two-phase dark matter detectors
• Neutral bremsstrahlung in two-phase argon electroluminescence: further studies and possible applications
• Measurement of emission spectrum for gaseous argon electroluminescence in visible light region from 300 to 600 nm
• Study of cryogenic photomultiplier tubes for the future two-phase cryogenic avalanche detector
• Detecting Low-Energy Interactions and the Effects of Energy Accumulation in Materials
• Observation of unusual slow components in electroluminescence signal of two-phase argon detector
• Study of visible-light emission in pure and methane-doped liquid argon
• Neutral Bremsstrahlung in TPCs

Cited by in corpus (3)

• First observation of neutral bremsstrahlung electroluminescence in liquid argon
• Unraveling the puzzle of slow components in gaseous argon of two-phase detectors for dark matter searches using Thick Gas Electron Multiplier
• Possible evidence for the production of Ar${}_2^{\ast -}$ metastable negative molecular ions in gaseous argon of two-phase detectors for dark matter searches