Development of enriched 106CdWO4 crystal scintillators to search for double β decay processes in 106Cd

A cadmium tungstate crystal scintillator enriched in 106Cd was developed for an experiment to search for double beta processes in 106Cd. With this aim samples of cadmium with natural isotopic composition and enriched in 106Cd were purified by vacuum distillation. Cadmium tungstate compounds were synthesized from solutions. The absolute isotopic composition of the enriched cadmium was accurately determined as 66.4% by thermal ionisation mass-spectrometry. A 106CdWO4 crystal boule was grown by the low-thermal-gradient Czochralski technique. The total irrecoverable loss of the enriched cadmium in all the stages of the crystal scintillator production does not exceed 2.3%. The produced 106CdWO4 crystal scintillator with mass of 216 g exhibits good optical and scintillation properties.