Low-energy (0.7-74 keV) nuclear recoil calibration of the LUX dark matter experiment using D-D neutron scattering kinematics

Abstract

The Large Underground Xenon (LUX) experiment is a dual-phase liquid xenon time projection chamber (TPC) operating at the Sanford Underground Research Facility in Lead, South Dakota. A calibration of nuclear recoils in liquid xenon was performed in situ in the LUX detector using a collimated beam of mono-energetic 2.45 MeV neutrons produced by a deuterium-deuterium (D-D) fusion source. The nuclear recoil energy from the first neutron scatter in the TPC was reconstructed using the measured scattering angle defined by double-scatter neutron events within the active xenon volume. We measured the absolute charge (Qy) and light (Ly) yields at an average electric field of 180 V/cm for nuclear recoil energies spanning 0.7 to 74 keV and 1.1 to 74 keV, respectively. This calibration of the nuclear recoil signal yields will permit the further refinement of liquid xenon nuclear recoil signal models and, importantly for dark matter searches, clearly demonstrates measured ionization and scintillation signals in this medium at recoil energies down to O(1 keV).

Quenching factor measurements of neon nuclei in neon gas

“…Lindhard theory is often used to compare with experimental results. It shows reasonable agreement in silicon and germanium but also in LXe and LAr [41], [44]. Two measurements in gases were performed in 4 He and isobutane, [16] [17].…”

Fast and Flexible Analysis of Direct Dark Matter Search Data with Machine Learning

“…The simulated background model is also the same as in [20], and includes gamma-rays from multiple locations, beta particles, 127 Xe, 37 Ar, and backgrounds originating from decays at the radial edge of the TPC ("wall backgrounds"). WIMP dark matter signal models covering a range of masses are generated using the Noble Element Simulation Technique (NEST) version 2.0.1 [35], tuned to match LUX calibration data as described in [3,24,36].…”

Observing the Migdal effect from nuclear recoils of neutral particles with liquid xenon and argon detectors

“…Detailed calculations of these cross sections have being carried out using the POD code and we make use of the results published in the JENDL-4.0 library [22]. This library provides a good fit to the calibration data obtained by the LUX collaboration [25]. We take the total elastic scattering cross section as the average of the cross section for all xenon isotopes (weighted by their naturally occurring abundances).…”

“…However, low energy recoils have a smaller probability of causing a Migdal event. The kinematics of the scattering can be approximated via the formula [25],…”