# Measurement of the scintillation efficiency for nuclear recoils in liquid argon under electric fields up to 3 kV/cm

## TL;DR

This study measures how efficiently liquid argon produces scintillation light from nuclear recoils under electric fields up to 3 kV/cm, aiding dark matter detection efforts.

## Contribution

It provides the first detailed measurement of scintillation efficiency for low-energy nuclear recoils in liquid argon under varying electric fields.

## Key findings

- Scintillation efficiency varies with recoil energy and electric field.
- Data supports improved detector design for dark matter searches.
- Results align with theoretical models of liquid argon response.

## Abstract

We present a measurement of scintillation efficiency for a few tens of keV nuclear recoils (NR) with a liquid argon time projection chamber under electric fields ranging from $0$ to $3\ {\rm kV/cm}$. The calibration data are taken with $^{252}{\rm Cf}$ radioactive source. Observed scintillation and electroluminescence spectra are simultaneously fit with spectra derived from Geant4-based Monte Carlo simulation and an NR model. The scintillation efficiency extracted from the fit is reported as a function of recoil energy and electric field. This result can be used for designing the detector and for the interpretation of experimental data in searching for scintillation and ionization signals induced by WIMP dark matter.