(EC + β+) decays of the 11/2- isomer and 1/2+ ground state of 143Dy

The 1/2+ ground state and a 11/2- isomer of very neutron-deficient isotope 143Dy were produced by irradiation of an enriched target of 106Cd with 40Ca and studied by using a helium-jet fast tape-transport system in combination with proton-γ, X-γ and γ-γ coincidence measurements. A simple ( EC + β+) decay scheme of 143mDy with a half-life of 3.0(3) s and a tentative ( EC + β+) decay scheme of 143gDy with a half-life of 5.6(10) s are proposed. As a by-product, the 347- and 545-keV γ transitions in 138Sm following the β-delayed proton emission of 139Gd decay and the 323-keV γ transition in 139Eu following the β-delayed proton emission of 140Tb decay could be observed for the first time.