Current status of the search for 2β decay of 106Cd using 106CdWO4 crystal scintillator.

An experiment to study 2β decay processes in ¹⁰⁶Cd using a ¹⁰⁶CdWO₄ crystal scintillator of mass 215.4 g enriched in 106Cd to 66% is ongoing in the DAMA/R&D setup at the LNGS of INFN (Italy). The events in the ¹⁰⁶CdWO₄ detector are recorded in (anti)coincidences with two large-volume CdWO₄ scintillation counters. The design of the detector system, the calibration and background measurements, methods and results of data analysis to determine key detector characteristics are described. The experimental data are compared with Monte Carlo simulation results, and a background model is constructed. The radioactive contamination of the setup components is studied. The limit on the half-life for the 2νεβ⁺ decay in ¹⁰⁶Cd was preliminarily estimated as lim T_1/2 = 3.5×10²¹, which approaches the theoretical expectations for this process. [ABSTRACT FROM AUTHOR]