First demonstration of a sub-keV electron recoil energy threshold in a liquid argon ionization chamber

Abstract

We describe the first demonstration of a sub-keV electron recoil energy threshold in a dual-phase liquid argon time projection chamber. This is an important step in an effort to develop a detector capable of identifying the ionization signal resulting from nuclear recoils with energies of order a few keV and below. We obtained this result by observing the peaks in the energy spectrum at 2.82 keV and 0.27 keV, following the K- and L-shell electron capture decay of Ar-37, respectively. The Ar-37 source preparation is described in detail, since it enables calibration that may also prove useful in dark matter direct detection experiments. An internally placed Fe-55 x-ray source simultaneously provided another calibration point at 5.9 keV. We discuss the ionization yield and electron recombination in liquid argon at those three calibration energies.

References in corpus (3)

• The Large Underground Xenon (LUX) Experiment
• Nuclear recoil energy scale in liquid xenon with application to the direct detection of dark matter
• Expected Sensitivity to Galactic/Solar Axions and Bosonic Super-WIMPs based on the Axio-electric Effect in Liquid Xenon Dark Matter Detectors

Cited by in corpus (18)

• Low-Mass Dark Matter Search with the DarkSide-50 Experiment
• First results from the NEWS-G direct dark matter search experiment at the LSM
• Investigation of background electron emission in the LUX detector
• A Review of Basic Energy Reconstruction Techniques in Liquid Xenon and Argon Detectors for Dark Matter and Neutrino Physics Using NEST
• First measurement of the ionization yield of nuclear recoils in liquid argon
• Electron extraction efficiency study for dual-phase xenon dark matter experiments
• Simulation of argon response and light detection in the DarkSide-50 dual phase TPC
• Calibration of a two-phase xenon time projection chamber with a ${}^{37}$Ar source
• Constraining active-sterile neutrino transition magnetic moments at DUNE near and far detectors
• Experimental study of ionization yield of liquid xenon for electron recoils in the energy range 2.8 - 80 keV
• X-ray ionization yields and energy spectra in liquid argon
• Proportional electroluminescence in two-phase argon and its relevance to rare-event experiments
• Measurement of the ionization yield of nuclear recoils in liquid argon using a two-phase detector with electroluminescence gap
• Low-Energy (<10 keV) Electron Ionization and Recombination Model for a Liquid Argon Detector
• Further studies of proportional electroluminescence in two-phase argon
• Using ${}^{22}$Na and ${}^{83\mathrm{m}}$Kr to calibrate and study the properties of scintillation in xenon-doped liquid argon
• Antineutrino Detectors Remain Impractical for Nuclear Explosion Monitoring
• Low-energy threshold demonstration for dark matter searches in TREX-DM with an ${}^{37}$Ar source produced at CNA HiSPANoS