Sensitivity enhancement techniques for cryogenic calorimeters in the NUCLEUS experiment
Abstract
Phonon-mediated cryogenic calorimeters find application in rare event searches due to their intrinsically low energy threshold. Achieving the best sensitivity for this kind of detectors is crucial for signal identification, leading to various optimization techniques. In this work, we present two complementary methods to increase the sensitivity of cryogenic detectors read out by transition-edge sensors, developed and tested in the context of the NUCLEUS experiment. The first procedure maps the signal-to-noise ratio of the device across a wide range of operating points, to identify the configuration with maximal sensitivity to be used during data taking. The second method exploits the double readout of the detector, combining the information on different channels with a two-dimensional optimum filter analysis that effectively lowers the energy threshold. With both techniques at the same time, we obtained a baseline resolution of 2.94 0.05 (stat) eV using a CaWO4 based detector, achieving a promising result in view of the first run of NUCLEUS at the experimental site.
Keywords
Cite
@article{arxiv.2603.28276,
title = {Sensitivity enhancement techniques for cryogenic calorimeters in the NUCLEUS experiment},
author = {M. Cappelli and A. Wallach and H. Abele and G. Angloher and B. Arnold and M. Atzori Corona and A. Bento and E. Bossio and F. Buchsteiner and J. Burkhart and F. Cappella and N. Casali and R. Cerulli and A. Cruciani and G. Del Castello and M. del Gallo Roccagiovine and S. Dorer and A. Erhart and M. Friedl and S. Fichtinger and V. M. Ghete and M. Giammei and C. Goupy and J. Hakenmüller and D. Hauff and F. Jeanneau and E. Jericha and M. Kaznacheeva and H. Kluck and A. Langenkämper and T. Lasserre and D. Lhuillier and M. Mancuso and R. Martin and B. Mauri and A. Mazzolari and L. McCallin and H. Neyrial and C. Nones and L. Oberauer and L. Peters and F. Petricca and W. Potzel and F. Pröbst and F. Pucci and F. Reindl and M. Romagnoni and J. Rothe and N. Schermer and J. Schieck and S. Schönert and C. Schwertner and L. Scola and G. Soum-Sidikov and L. Stodolsky and A. Schröder and R. Strauss and R. Thalmeier and C. Tomei and L. Valla and M. Vignati and M. Vivier and P. Wasser and A. Wex and L. Wienke},
journal= {arXiv preprint arXiv:2603.28276},
year = {2026}
}