Development of cryogenic calorimeters to measure the spectral shape of In-115 beta decay

TL;DR

This paper proposes using cryogenic In$_2$O$_3$ calorimeters to precisely measure the spectral shape of $^{115}$In beta decay, which is vital for nuclear physics and astrophysics, and discusses preliminary results and future improvements.

Contribution

Introduction of a cryogenic calorimeter based on In$_2$O$_3$ for high-precision spectral measurements of $^{115}$In beta decay, advancing experimental techniques in this area.

Findings

Preliminary test results of In$_2$O$_3$ crystal calorimeter.

Discussion of detector performance improvements.

Next steps for enhanced measurement accuracy.

Abstract

The spectral shape of forbidden beta-decays is a crucial benchmark for nuclear physics calculations and has important implications also for astroparticle physics experiments. Among the interesting isotopes in this field, $^{115}$In is an excellent candidate, being a primordial nuclide featuring a good compromise among Q-value (497.954 keV) and half-life (4.41$\times$10$^{14}$ yr). In this paper, we propose to exploit a cryogenic calorimeter based on In$_2$O$_3$ crystal to perform a high-precision measurement of the $\beta$-decay energy spectrum, discussing also the results obtained within a preliminary test of this crystal and the next steps to improve the detector performance.