First observation of 162Hf decay: Completion of an α-decay chain

The new isotope 162Hf (Tsub(1/2) = (37.6 +- 0.8)s) was produced in a 142Nd (24Mg,4n) reaction. The activities produced in this reaction were transported to a measuring station by use of a He-jet system. decay properties were observed with α-, γ-, and γ-γ - spectroscopy. The Z-assignment of the new isotope was based on a cross bombardment on 141Pr target and on the results of a γ-X-ray coincidence measurement. The mass assignment was deduced from excitation function measurements. From the measured α-decay energy Esub(α) = 4308 (10) keV new mass values were derived for 162Hf, 166W, 170Os, 174Pt, and 178Hg. These new mass values make it possible to establish systematics of two-proton and one-proton binding energies far from stability. (orig.)