Author:
Ahmine A.,Bandac I.C.,Barabash A.S.,Berest V.,Bergé L.,Calvo-Mozota J.M.,Carniti P.,Chapellier M.,Dafinei I.,Danevich F.A.,Dixon T.,Dumoulin L.,Ferri F.,Giuliani A.,Gotti C.,Gras P.,Helis D.L.,Ianni A.,Imbert L.,Khalife H.,Kobychev V.V.,Konovalov S.I.,Loaiza P.,de Marcillac P.,Marnieros S.,Marrache-Kikuchi C.A.,Martinez M.,Nones C.,Olivieri E.,Ortiz de Solórzano A.,Peinaud Y.,Pessina G.,Poda D.V.,Redon Th.,Rosier Ph.,Scarpaci J.A.,Tretyak V.I.,Umatov V.I.,Velazquez M.,Zarytskyy M.M.,Zolotarova A.
Abstract
Abstract
In preparation for the CROSS experiment to search for
double-beta (2β) decay of 100Mo, we upgraded a
low-background facility at the Canfranc underground laboratory
(Spain) by installing a magnetic damping-based detector suspension
inside a pulse-tube cryostat. We tested the suspension in
low-temperature (15 mK) measurements with two scintillating
bolometers made of large-volume crystals of 116CdWO4
(reference of the set-up) and Li2MoO4 (R&D of the CLYMENE
project in view of the CUPID 2β experiment), each coupled to a
thin Ge bolometric light detector. Despite the evidence of a
residual pulse-tube-induced noise, picked up by cabling, we achieved
high performance with all tested devices. In particular, the energy
resolution for 2615 keV γ-ray measured with both
116CdWO4 and Li2MoO4 bolometers is ∼6 keV FWHM,
among the best-reported results for thermal detectors based on such
compounds representing a great interest to searches for 2β
decay in 116Cd (Q-value is 2813 keV) and 100Mo
(3034 keV) respectively. Highly efficient particle identification
(α vs. β/γ) is achieved also with the
scintillating bolometer made of a low light yield crystal
(Li2MoO4), thanks to the low noise (10 eV RMS) exhibited by
the light detector exploiting the Neganov-Trofimov-Luke effect for
signal amplification. We also found a rather high level of
radiopurity in the Li2MoO4 crystal; only traces of 210Po
and 226Ra were detected (∼0.1 mBq/kg each), while the
228Th activity is expected to be at least an order of magnitude
lower, as well as a 40K activity is below 6 mBq/kg.
Subject
Mathematical Physics,Instrumentation