Intruder states in odd-odd Tl nuclei populated in the α-decay of odd-odd Bi isotopes

Abstract

The α-decay of mass separated 190,192,194,196Bi isotopes has been studied with the LISOL on-line separator. Time sequential α-singles spectra were taken and for 190,192,194Bi, αXt and αγt coincidences were collected. Transition probabilities of levels in 186,188,190Tl were measured using a fast timing αγt and αe −t coincidence set up. The α-decay of 196Bi and the β-decay of 190Bi are observed for the first time. In all the Bi nuclei presently studied, unhind3red α-decay of Bi starting from the high- (10 −) and low-spin (3 +) isomer populating intruder-based states in Tl was observed. The excitation energy of these intruder states is comparable with the intruder states in the neighboring odd-even and even-even nuclei.