We present the performances of two 92% enriched 130TeO2 crystals operated as thermal bolometers in view of a next generation experiment to search for neutrinoless double beta decay of 130Te. The crystals, 435 g each, show an energy resolution, evaluated at the 2615 keV Î³-line of 208Tl, of 6.5 and 4.3 keV FWHM. The only observable internal radioactive contamination arises from 238U (15 and 8 Î¼Bq/kg, respectively). The internal activity of the most problematic nuclei for neutrinoless double beta decay, 226Ra and 228Th, are both evaluated as <3.1 Î¼Bq/kg for one crystal and <2.3 Î¼Bq/kg for the second. Thanks to the readout of the weak Cherenkov light emitted by Î²/Î³ particles by means of NeganovâLuke bolometric light detectors we were able to perform an event-by-event identification of Î²/Î³ events with a 95% acceptance level, while establishing a rejection factor of 98.21% and 99.99% for Î± particles.
|Titolo:||Enriched TeO2 bolometers with active particle discrimination: Towards the CUPID experiment|
|Data di pubblicazione:||2017|
|Appare nelle tipologie:||Articolo su Rivista|