The new isotope 208Th

Abstract

The new neutron-deficient isotope 208Th was produced in the complete-fusion reaction 64Ni + 147Sm \( \rightarrow\) 208Th + 3n . Evaporation residues were separated in-flight by the velocity filter SHIP and subsequently identified on the basis of energy-, position- and time-correlated \( \alpha\) -decay chains. The measured \( \alpha\) -decay energy and half-life value of 208Th are 8044(30)keV and 1.7+1.7 -0.6 ms, respectively. Improved data on the \( \alpha\) -decay of 209Th , 210Th , 212Th and 208Ra were obtained using complete-fusion reactions of 64Ni with 147Sm , 150Sm , and 152Sm targets.