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

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 × 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 β-decay energy spectrum, discussing also the results obtained within a preliminary test of this crystal and the next steps to improve the detector performance.