Scintillation yield from electronic and nuclear recoils in superfluid ${}^4$He

Abstract

Superfluid ${}^4$He is a promising target material for direct detection of light ($<$ 1 GeV) dark matter. Possible signal channels available for readout in this medium include prompt photons, triplet excimers, and roton and phonon quasiparticles. The relative yield of these signals has implications for the sensitivity and discrimination power of a superfluid ${}^4$He dark matter detector. Using a 16~cm${}^3$ volume of 1.75~K superfluid ${}^4$He read out by six immersed photomultiplier tubes, we measured the scintillation from electronic recoils ranging between 36.3 and 185 keV${}_{\mathrm{ee}}$, yielding a mean signal size of $1.25_{-0.03}^{+0.03}$~phe/keV${}_{\mathrm{ee}}$, and nuclear recoils from 53.2 to 1090 keV${}_{\mathrm{nr}}$. We compare the results of our relative scintillation yield measurements to an existing semiempirical model based on helium-helium and electron-helium interaction cross sections. We also study the behavior of delayed scintillation components as a function of recoil type and energy, a further avenue for signal discrimination in superfluid ${}^4$He.

17 pages, 19 figures

References in corpus (4)

• Evidence of delayed light emission of TetraPhenyl Butadiene excited by liquid Argon scintillation light
• Dark Matter Detection Using Helium Evaporation and Field Ionization
• Effect of an electric field on liquid helium scintillation produced by fast electrons
• Cryogenic phonon-scintillation detectors with PMT readout for rare event search experiments

Cited by in corpus (10)

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• Dark Matter-Electron Scattering Search Using Cryogenic Light Detectors
• Characterization of FBK NUV-HD-Cryo SiPMs near LHe temperature
• A portable and high intensity 24 keV neutron source based on ${}^{124}$Sb-${}^9$Be photoneutrons and an iron filter
• A novel nuclear recoil calibration for liquid noble gas detectors
• Response of a Liquid ${}^3$He Neutron Detector
• Signal partitioning in superfluid ${}^4$He: a Monte Carlo approach
• Liquid ${}^3$He Detectors for Neutrons