https://doi.org/10.1140/epja/s10050-023-01090-9
Special Article - New Tools and Techniques
Development of low-background Cs
ZrCl
detectors to study rare decays in Zr isotopes
1
Dipartimento di Fisica, Università di Roma “Tor Vergata”, 00133, Rome, Italy
2
INFN, Sezione di Roma “Tor Vergata”, 00133, Rome, Italy
3
INFN, Sezione di Roma, 00185, Rome, Italy
4
Dipartimento di Fisica, Università di Roma “La Sapienza”, 00185, Rome, Italy
5
INFN Laboratori Nazionali del Gran Sasso, 67100, Assergi, AQ, Italy
6
Department of Physics, Engineering Physics and Astronomy, Queen’s University, K7L 3N6, Kingston, ON, Canada
7
Arthur B. McDonald Canadian Astroparticle Physics Research Institute, K7L 3N6, Kingston, ON, Canada
8
Department of Chemistry, Queen’s University, K7L 3N6, Kingston, ON, Canada
Received:
8
March
2023
Accepted:
12
July
2023
Published online:
30
July
2023
In this work, we present the first complex study of CsZrCl (CZC) scintillating crystals in terms of their chemical purity, crystal radiopurity, scintillating performance and pulse-shape discrimination ability. An ICP-MS measurement exhibits a high purity of the CZC material (overall impurity level less than 10 
g/g). The CZC crystals show a very low content of radionuclides from U/Th natural decay chains. For 
K and 
Cs only limits at the level few mBq/kg were set after more than 650 h of measurement with a high purity germanium (HPGe) detector. Nevertheless, they contained cosmogenic 
Cs with an activity of about 50 mBq/kg. The measurements with two CZC crystals (11 and 24 g) as scintillating detectors over 456.5 d in the low-background DAMA/CRYS facility, deep underground at LNGS, supported a substantial radiopurity of these crystals leading to a counting rate of 0.17
(kg
keVyr)
at the 
of 
Zr (3.35 MeV). These detectors show a high particle-discrimination ability for 
and 
particles. Limits on the half-lives of the double beta decays (DBD) of Zr and of 
Zr with and without neutrinos emission were also set at the level 
–
yr (90
C.L.). The detailed analyses of the internal background components will also be useful for further developments of CsZrCl low-background scintillating detectors and for the optimization of the experimental conditions.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2023. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
