Scintillation efficiency of liquid argon in low energy neutron-argon scattering

TL;DR

This study measures how efficiently liquid argon produces scintillation light when struck by low-energy neutrons, which is vital for detecting weakly interacting particles like dark matter.

Contribution

It provides new measurements of liquid argon scintillation efficiency at low recoil energies using a monoenergetic neutron beam.

Findings

Scintillation efficiency varies with recoil energy.

Results help calibrate liquid argon detectors for dark matter searches.

Data covers recoil energies from 11 to 120 keV.

Abstract

Experiments searching for weak interacting massive particles with noble gases such as liquid argon require very low detection thresholds for nuclear recoils. A determination of the scintillation efficiency is crucial to quantify the response of the detector at low energy. We report the results obtained with a small liquid argon cell using a monoenergetic neutron beam produced by a deuterium-deuterium fusion source. The light yield relative to electrons was measured for six argon recoil energies between 11 and 120 keV at zero electric drift field.