Search for double electron capture of 106Cd in TGV-2 experiment

Experiment to seek double electron capture in 106Cd decay took place in the Modane underground laboratory (4800 m depth). By means of the TGV-2 low-background multidetector spectrometer one investigated into thin (∼ 50 μm thickness) specimens of enriched 106Cd and of natural Cd. On the basis of the preliminary processing of data acquired in 3400 hour course of efforts to measure 10 g of enriched 106Cd (75% enrichment) one determined new limits (90% confidence limit) for various branches of 106Cd decay into ground (0+) and first excited state (2+, 512 keV) of a daughter nucleus. They constitute T1/2(2νβ+EC) ≥ 4.1 x 1019 g and T1//2(2νEC/EC) ≥ 5.6 x 1019 g (for 0+ → 0+, g.s. transitions) and T1/2(2νβ+EC) → 5.8 x 1019 g and T1/2(2νEC/EC) ≥ 2.1 x 1019 g