Measurement of Scintillation and Ionization Yield and Scintillation Pulse Shape from Nuclear Recoils in Liquid Argon

Abstract

We have measured the scintillation and ionization yield of recoiling nuclei in liquid argon as a function of applied electric field by exposing a dual-phase liquid argon time projection chamber (LAr-TPC) to a low energy pulsed narrow band neutron beam produced at the Notre Dame Institute for Structure and Nuclear Astrophysics. Liquid scintillation counters were arranged to detect and identify neutrons scattered in the TPC and to select the energy of the recoiling nuclei. We report measurements of the scintillation yields for nuclear recoils with energies from 10.3 to 57.3 keV and for median applied electric fields from 0 to 970 V/cm. For the ionization yields, we report measurements from 16.9 to 57.3 keV and for electric fields from 96.4 to 486 V/cm. We also report the observation of an anticorrelation between scintillation and ionization from nuclear recoils, which is similar to the anticorrelation between scintillation and ionization from electron recoils. Assuming that the energy loss partitions into excitons and ion pairs from ${}^{83m}$Kr internal conversion electrons is comparable to that from ${}^{207}$Bi conversion electrons, we obtained the numbers of excitons ($N_{ex}$) and ion pairs ($N_i$) and their ratio ($N_{ex}/N_i$) produced by nuclear recoils from 16.9 to 57.3 keV. Motivated by arguments suggesting direction sensitivity in LAr-TPC signals due to columnar recombination, a comparison of the light and charge yield of recoils parallel and perpendicular to the applied electric field is presented for the first time.

v2 to reflect published version

References in corpus (7)

• Dark Matter Results from 225 Live Days of XENON100 Data
• The Large Underground Xenon (LUX) Experiment
• First results from a Dark Matter search with liquid Argon at 87 K in the Gran Sasso Underground Laboratory
• A Model of Nuclear Recoil Scintillation Efficiency in Noble Liquids
• Observation of Anti-correlation between Scintillation and Ionization for MeV Gamma-Rays in Liquid Xenon
• First results on light readout from the 1-ton ArDM liquid argon detector for dark matter searches
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Cited by in corpus (23)

• First Results from the DarkSide-50 Dark Matter Experiment at Laboratori Nazionali del Gran Sasso
• A Review of Basic Energy Reconstruction Techniques in Liquid Xenon and Argon Detectors for Dark Matter and Neutrino Physics Using NEST
• Simulation of argon response and light detection in the DarkSide-50 dual phase TPC
• ${}^{83\text{m}}$Kr calibration of the 2013 LUX dark matter search
• Pulseshape discrimination against low-energy Ar-39 beta decays in liquid argon with 4.5 tonne-years of DEAP-3600 data
• Direct Detection of Dark Matter -- APPEC Committee Report
• Properties of Liquid Argon Scintillation Light Emission
• Calibration of the liquid argon ionization response to low energy electronic and nuclear recoils with DarkSide-50
• Sensitivity projections for a dual-phase argon TPC optimized for light dark matter searches through the ionization channel
• Proposed low-energy absolute calibration of nuclear recoils in a dual-phase noble element TPC using D-D neutron scattering kinematics
• Time-integrated directional detection of dark matter
• Measurement of Charge and Light Yields for ${}^{127}$Xe L-Shell Electron Captures in Liquid Xenon
• Directional Detection of Dark Matter Using Solid-State Quantum Sensing
• Large Low Background kTon-Scale Liquid Argon Time Projection Chambers
• Neutrino Backgrounds in Future Liquid Noble Element Dark Matter Direct Detection Experiments
• Dark Matter Detection Capabilities of a Large Multipurpose Liquid Argon Time Projection Chamber
• Measurement of the ionization yield of nuclear recoils in liquid argon using a two-phase detector with electroluminescence gap
• Effect of Low Electric Fields on Alpha Scintillation Light Yield in Liquid Argon
• ALETHEIA: Hunting for Low-mass Dark Matter with Liquid Helium TPCs
• Characterization of the scintillation time response of liquid argon detectors for dark matter search
• Relative Measurement and Extrapolation of the Scintillation Quenching Factor of $\alpha$-Particles in Liquid Argon using DEAP-3600 Data
• Performance of the ReD TPC, a novel double-phase LAr detector with Silicon Photomultiplier Readout
• Characterization of argon recoils at the keV scale with ReD and ReD+