A lab scale experiment for keV sterile neutrino search

TL;DR

This paper presents a small-scale experimental setup using a LiF crystal and microcalorimeter to measure tritium beta decay spectra, aiming to detect keV-scale sterile neutrinos.

Contribution

It introduces a novel, simplified experimental method for searching for sterile neutrinos in the keV mass range using beta decay spectra.

Findings

Spectrum measurement agrees with expected $^3$H decay

Method shows potential for sterile neutrino search

Sample preparation and analysis are effectively demonstrated

Abstract

We developed a simple small-scale experiment to measure the beta decay spectrum of $^{3}$H. The aim of this research is to investigate the presence of sterile neutrinos in the keV region. Tritium nuclei were embedded in a 1$\times$1$\times$1 cm$^3$ LiF crystal from the $^6$Li(n,$\alpha$)$^3$H reaction. The energy of the beta electrons absorbed in the LiF crystal was measured with a magnetic microcalorimeter at 40 mK. We report a new method of sample preparation, experiments, and analysis of $^3$H beta measurements. The spectrum of a 10-hour measurement agrees well with the expected spectrum of $^3$H beta decay. The analysis results indicate that this method can be used to search for keV-scale sterile neutrinos.