High sensitivity characterization of an ultrahigh purity NaI(Tl) crystal scintillator with the SABRE proof-of-principle detector
F Calaprice, S Copello, I Dafinei, D D'Angelo, G D'Imperio, G Di Carlo, M Diemoz, A Di Giacinto, A Di Ludovico, A Ianni, M Iannone, F Marchegiani, A Mariani, S Milana, S Nisi, F Nuti, D Orlandi, V Pettinacci, L Pietrofaccia, S Rahatlou Show all
PHYSICAL REVIEW D | AMER PHYSICAL SOC | Published : 2021
We present new results on the radiopurity of a 3.4-kg NaI(Tl) crystal scintillator operated in the SABRE proof-of-principle detector setup. The amount of potassium contamination, determined by the direct counting of radioactive K40, is found to be 2.2±1.5 ppb, lowest ever achieved for NaI(Tl) crystals. With the active veto, the average background rate in the crystal in the 1-6 keV energy region of interest (ROI) is 1.20±0.05 counts/day/kg/keV, which is a breakthrough since the DAMA/LIBRA experiment. Our background model indicates that the rate is dominated by Pb210 and that about half of this contamination is located in the polytetrafluoroethylene reflector. We discuss ongoing developments o..View full abstract
Awarded by National Science Foundation
This work was supported by INFN funding and National Science Foundation under the Awards No. PHY-1242625, No. PHY-1506397, and No. PHY-1620085. We thank Ezio Previtali, Andrea Giuliani, and Monica Sisti for discussions about PTFE radiopurity in CUORE. We thank Fausto Ortica and Aldo Romani from Perugia University for support in photospectrometric measurements. We thank the Gran Sasso Laboratory for the support during the installation of the SABRE PoP setup.