On the limit of nuclear stability - the region of double magic 100Sn and bound-state β-decay of 187Re75+

Experiments which led to the discovery of the heaviest, self-conjugated double magic nucleus 100Sn and the bound-state β-decay of completely ionized 187Re are presented. 100Sn was produced by fragmentation of 1.1 A GeV 124Xe beams, separated and implanted in a 4πSi-stack detector. From its decay a half-life T1/2=0.94(+0.54,-0.27) s and a β+ endpoint energy of Eβ = 3.4(+0.7, -0.3) MeV were determined for the 0+-1+ Gamov-Teller transition. Completely stripped 187Re75+ was produced and stored in a coolerring with an energy of 351 A MeV for several hours. The products of bound-state β-decay of 187Re75+ were detected by two independent methods, which allowed to determine a half-life of T1/2=33±6 y for this decay, which is of importance for the calibration of the Re/Os nucleosynthesis chronometer. (orig.)