Background optimization for a new spherical gas detector for very light WIMP detection

TL;DR

This paper discusses the background optimization of a spherical gas detector designed for detecting very light WIMPs, highlighting its low energy threshold, background reduction techniques, and potential for dark matter detection.

Contribution

It introduces background reduction methods and calibration techniques for a spherical gas detector aimed at low-mass WIMP detection, enhancing its sensitivity.

Findings

Achieved energy calibration with 37Ar

Reduced surface background levels

Projected sensitivity for light dark matter detection

Abstract

The Spherical gaseous detector (or Spherical Proportional Counter, SPC) is a novel type of par- ticle detector, with a broad range of applications. Its main features include a very low energy threshold independent of the volume (due to its very low capacitance), a good energy resolution, robustness and a single detection readout channel, in its simplest version. Applications range from radon emanation gas monitoring, neutron flux and gamma counting and spectroscopy to dark matter searches, in particular low mass WIMPs and coherent neutrino scattering measure- ment. Laboratories interested in these various applications share expertise within the NEWS (New Experiments With Sphere) network. SEDINE, a low background prototype installed at underground site of Laboratoire Souterrain de Modane is currently being operated and aims at measuring events at very low energy threshold, around 100 eV. We will present the energy cali- bration with 37Ar, the surface background reduction, the measurement of detector background at sub-keV energies, and show anticipated sensitivities for light dark matter search.