LiFE-SNS: LiF Experiment for keV-scale Sterile Neutrino Search

TL;DR

LiFE-SNS is a novel experiment designed to detect keV-scale sterile neutrinos by precisely measuring the tritium beta spectrum using advanced calorimetric detectors embedded in LiF crystals.

Contribution

This work introduces the detector setup, calibration, and characterization methods for LiFE-SNS, enabling high-precision beta spectrum measurements for sterile neutrino searches.

Findings

Successful detector calibration and characterization.

Modeling of position-dependent response and nonlinearity.

Projected sensitivity indicates competitive sterile neutrino search capability.

Abstract

The LiF Experiment for keV-scale Sterile Neutrino Search (LiFE-SNS) aims to probe sterile neutrinos through precision measurements of the tritium $\beta$ spectrum. Tritium nuclei are produced and embedded in LiF crystals via the ${}^{6}\mathrm{Li}(n,\alpha){}^{3}\mathrm{H}$ reaction, allowing thermal calorimetric detection of $\beta$ decays with magnetic microcalorimeters (MMCs) operated at millikelvin temperatures. We present the detector configuration, background studies, and calibration method, including modeling of position-dependent response and characterization of detector nonlinearity. We also discuss potential sources of systematic uncertainty relevant to the sterile-neutrino search. While the first phase of LiFE-SNS has been completed, this paper focuses on calibration and detector characterization. The achieved performance enables precision $\beta$-spectrum measurements, and projected sensitivities indicate competitive reach in the keV mass region.