Background identification in cryogenic calorimeters through $\alpha -\alpha $ delayed coincidences

O. Azzolini , J.W. Beeman , F. Bellini , M. Beretta , M. Biassoni , C. Brofferio , C. Bucci , S. Capelli , L. Cardani , P. Carniti , N. Casali , D. Chiesa , M. Clemenza , O. Cremonesi , A. Cruciani , I. Dafinei , A. d'Addabbo , S. Di Domizio , F. Ferroni , L. Gironi , A. Giuliani (1) , P. Gorla , C. Gotti , G. Keppel , M. Martinez , S. Nagorny , M. Nastasi , S. Nisi , C. Nones (2) , D. Orlandi , L. Pagnanini , M. Pallavicini , L. Pattavina , M. Pavan , G. Pessina , V. Pettinacci , S. Pirro , S. Pozzi , E. Previtali , A. Puiu , C. Rusconi , K. Schäffner , C. Tomei , M. Vignati , A. Zolotarova (1)

1 CSNSM - Centre de Sciences Nucléaires et de Sciences de la Matière
2 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers

Localization and modeling of radioactive contaminations is a challenge that ultra-low background experiments are constantly facing. These are fundamental steps both to extract scientific results and to further reduce the background of the detectors. Here we present an innovative technique based on the analysis of $\alpha -\alpha $ delayed coincidences in ${}^{232}$Th and ${}^{238}$U decay chains, developed to investigate the contaminations of the ZnSe crystals in the CUPID-0 experiment. This method allows to disentangle surface and bulk contaminations of the detectors relying on the different probability to tag delayed coincidences as function of the $\alpha $ decay position.

Domaines: Instrumentations et Détecteurs [physics.ins-det]; Physique Nucléaire Expérimentale [nucl-ex]; Analyse de données, Statistiques et Probabilités [physics.data-an]

O. Azzolini, J.W. Beeman, F. Bellini, M. Beretta, M. Biassoni, et al.. Background identification in cryogenic calorimeters through $\alpha -\alpha $ delayed coincidences. European Physical Journal C: Particles and Fields, 2021, 81 (8), pp.722. ⟨10.1140/epjc/s10052-021-09476-z⟩. ⟨hal-03235683⟩