CdWO4 crystal scintillators from enriched isotopes for double beta decay experiments

Cadmium tungstate crystal scintillators enriched in 106Cd and 116Cd were developed. The produced scintillators exhibit good optical and scintillation properties, and a low level of radioactive contamination. Experiments to search for double beta decay of 106Cd and 116Cd are in progress at the Gran Sasso National Laboratories of the INFN (Italy). Prospects to further improve the radiopurity of the detectors by recrystallization are discussed.

► We developed cadmium tungstate scintillators enriched in 106Cd and 116Cd isotopes. ► The total irrecoverable losses of the enriched Cd on all the stages: <3%. ► The produced 106,116CdWO4 exhibit good scintillation properties and high radiopurity. ► Low segregation of K, Ra, and Th by cadmium tungstate crystals has been observed. ► Double beta experiments by using 106,116CdWO4 are in progress deep underground.