We present here an innovative cryogenic light detector capable to measure a few tens of eV signal thanks to the amplification assisted by the Neganov-Luke effect. The thermal signal boost in the presence of an electric field allows us to improve the signal-to-noise ratio reaching a baseline noise of around 20 eV. This device - coupled to an enriched 130TeO2 bolometer (435 g) - registered 160 eV Cherenkov light signal induced by 2615 keV208Tl with a signal to noise ratio about 6:1. Since α particles emitted in decays of natural radionuclides do not produce the Cherenkov radiation, we were able to achieve an efficient α/γ separation in the region of interest for neutrinoless double beta decay of130Te (Q-value is 2527 keV). Specifically, a rejection factor of 99.9% for α particles was obtained with a 98.3% acceptance of β/γ events. The achieved α rejection efficiency is required to reduce the dominant α background in the follow-up of the CUORE experiment (CUPID), a ton-scale bolometric search with particle identification
An innovative bolometric Cherenkov-light detector for a double beta decay search
Pagnanini, L.;
2018-01-01
Abstract
We present here an innovative cryogenic light detector capable to measure a few tens of eV signal thanks to the amplification assisted by the Neganov-Luke effect. The thermal signal boost in the presence of an electric field allows us to improve the signal-to-noise ratio reaching a baseline noise of around 20 eV. This device - coupled to an enriched 130TeO2 bolometer (435 g) - registered 160 eV Cherenkov light signal induced by 2615 keV208Tl with a signal to noise ratio about 6:1. Since α particles emitted in decays of natural radionuclides do not produce the Cherenkov radiation, we were able to achieve an efficient α/γ separation in the region of interest for neutrinoless double beta decay of130Te (Q-value is 2527 keV). Specifically, a rejection factor of 99.9% for α particles was obtained with a 98.3% acceptance of β/γ events. The achieved α rejection efficiency is required to reduce the dominant α background in the follow-up of the CUORE experiment (CUPID), a ton-scale bolometric search with particle identificationI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
