Search for 2β decay of 116Cd with the help of enriched 116CdWO4 crystal scintillators

Abstract

Cadmium tungstate crystal scintillators enriched in ${}^{116}$Cd to 82% (${}^{116}$CdWO${}_4$, total mass of $\approx$1.2 kg) are used to search for 2$\beta$ decay of ${}^{116}$Cd deep underground at the Gran Sasso National Laboratory of the INFN (Italy). The radioactive contamination of the ${}^{116}$CdWO${}_4$ crystals has been studied carefully to reconstruct the background of the detector. The measured half-life of ${}^{116}$Cd relatively to 2$\nu$2$\beta$ decay is $T_{1/2}^{2\nu 2\beta }$ = [2.8 $\pm$ 0.05(stat.) $\pm$ 0.4(syst.)] $\times$ 10${}^{19}$ yr, in agreement with the results of previous experiments. The obtained limit on the 0$\nu$2$\beta$ decay of ${}^{116}$Cd (considering the data of the last 8696 h run with an advanced background 0.12(2) counts/yr/kg/keV in the energy interval 2.7-2.9 MeV) is $T_{1/2}\ge 1.0\times 10^{23}$ yr at 90% C.L. The sensitivity of the experiment to the $0\nu 2\beta$ process is $\lim T_{1/2}=3\times 10^{23}$ yr at 90% C.L. over 5 years of the measurements and it can be advanced (by further reduction of the background by a factor 3-30) to the level of $\lim T_{1/2}=(0.5-1.5)\times 10^{24}$ yr for the same period of the data taking.

Contribution to Proc. of Int. Workshop on Radiopure Scintillators RPSCINT 2013, 17-20.09.2013, Kyiv, Ukraine; to be published in EPJ Web of Conferences; 4 pages, 1 figure and 3 tables

References in corpus (6)

• Theory of neutrinoless double beta decay
• Precise half-life values for two neutrino double beta decay
• Recent Progress in Double Beta Decay
• Further study of CdWO4 crystal scintillators as detectors for high sensitivity double beta experiments: scintillation properties and pulse-shape discrimination
• Experimental study of double beta decay modes using a CdZnTe detector array
• CdWO4 crystal scintillators from enriched isotopes for double beta decay experiments

Cited by in corpus (5)

• Average and recommended half-life values for two neutrino double beta decay
• Final results of the Aurora experiment to study 2$\beta$ decay of ${}^{116}$Cd with enriched ${}^{116}$CdWO${}_4$ crystal scintillators
• Improvement of radiopurity level of enriched ${}^{116}$CdWO${}_4$ and ZnWO${}_4$ crystal scintillators by recrystallization
• Search for double beta decay of ${}^{116}$Cd with enriched ${}^{116}$CdWO${}_4$ crystal scintillators (Aurora experiment)
• First test of an enriched ${}^{116}$CdWO${}_4$ scintillating bolometer for neutrinoless double-beta-decay searches