Development of radiopure cadmium tungstate crystal scintillators from enriched 106Cd anD 116Cd to search for double beta decay

Cadmium tungstate crystal scintillators enriched in 106Cd up to 66% (106CdWO4) and in 116Cd up to 82% (116CdWO4) have been developed. The low radioactive contamination of the crystals measured on the level of ≤ 1.5 mBq/kg (40K), ≤ 0.005 - 0.012 mBq/kg (226Ra), 0.04 - 0.07 mBq/kg (228Th) allows to carry out high sensitivity experiments to search for double beta processes in 106Cd and 116Cd.