THE RESEARCH OF 2-BETA DECAY OF CD-116 WITH ENRICHED (CDWO4)-CD-116 CRYSTAL SCINTILLATORS

The experiment was performed at the Solotvina Underground Laboratory w ith CdWO4 crystal scintillators enriched in Cd-116 to 83%. The total d ata collection time was about 30000 hours. Limits of T-1/2(0v) greater than or equal to 2.9.10(22) y (90% CL) and T-1/2(2v) greater than or equal to 1.8.10(19) y (99% CL) were obtained for 0v2 beta and 2v2 beta decay of Cd-116. After subtraction of the spectrum obtained with a na tural CdWO4 scintillator a remaining yield was seen consistent with 2v 2 beta decay of Cd-116 with T-1/2(2v) = {2.7(-0.4)(+0.5) (stat.)(-0.6) (+0.9)(syst.)}.10(19) y. However, the imitation of the effect by impur ities of Sr-90 (at the level of 2.10(-3) Bq/kg) cannot be excluded.