The COSINUS direct dark matter experiment situated at Laboratori Nazionali del Gran Sasso in Italy is set to investigate the nature of the annually modulating signal detected by the DAMA/LIBRA experiment. COSINUS has already demonstrated that sodium iodide crystals can be operated at mK temperature as cryogenic scintillating calorimeters using transition edge sensors, despite the complication of handling a hygroscopic and low melting point material. With results from a new COSINUS prototype, we show that particle discrimination on an event-by-event basis in NaI is feasible using the dual-channel readout of both phonons and scintillation light. The detector was mounted in the novel remoTES design and operated in an above-ground facility for 9.06 g⋅d of exposure. With a 3.7 g NaI crystal, e−/γ events could be clearly distinguished from nuclear recoils down to the nuclear recoil energy threshold of 15 keV.
@article{arxiv.2307.11066,
title = {Particle discrimination in a NaI crystal using the COSINUS remote TES design},
author = {COSINUS Collaboration and G. Angloher and M. R. Bharadwaj and I. Dafinei and N. Di Marco and L. Einfalt and F. Ferroni and S. Fichtinger and A. Filipponi and T. Frank and M. Friedl and A. Fuss and Z. Ge and M. Heikinheimo and M. N. Hughes and K. Huitu and M. Kellermann and R. Maji and M. Mancuso and L. Pagnanini and F. Petricca and S. Pirro and F. Pröbst and G. Profeta and A. Puiu and F. Reindl and K. Schäffner and J. Schieck and D. Schmiedmayer and C. Schwertner and M. Stahlberg and A. Stendhal and M. Stukel and C. Tresca and F. Wagner and S. Yue and V. Zema and Y. Zhu and A. Bento and L. Canonica and A. Garai},
journal= {arXiv preprint arXiv:2307.11066},
year = {2024}
}