Search for double electron capture of 106Cd

A search for double electron capture of 106Cd was performed at the Modane Underground Laboratory (4800 m w.e.) using a low-background and high-sensitivity multidetector spectrometer TGV-2 (Telescope Germanium Vertical). New limits on β+/EC, EC/EC decays of 106Cd were obtained from preliminary calculations of experimental data accumulated for 4800 h of measurement of 10 g of 106Cd with enrichment of 75%. They are \(T_{{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-\nulldelimiterspace} 2}}^{2\nu \beta ^ + EC} \) > 9.1 × 1018 yr, \(T_{{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-\nulldelimiterspace} 2}}^{2\nu {{EC} \mathord{\left/ {\vphantom {{EC} {EC}}} \right. \kern-\nulldelimiterspace} {EC}}} \) > 1.9 × 1019 yr for transitions to the first 2+, 511.9 keV excited state of 106Pd, and \(T_{{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-\nulldelimiterspace} 2}}^{2\nu \beta ^ + EC} \) > 1.3 × 1019 yr, \(T_{{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-\nulldelimiterspace} 2}}^{2\nu {{EC} \mathord{\left/ {\vphantom {{EC} {EC}}} \right. \kern-\nulldelimiterspace} {EC}}} \) > 6.2 × 1019 yr for transitions to the ground 0+ state of 106Pd. All limits are given at 90% C.L.