α-decay spectroscopy of light odd-odd Bi isotopes - I: 188,190Bi nuclei.

Detailed fine-structure a-decay studies of ^188,190Bi were performed using the complete-fusion reactions of ^50,52Cr ions with a ¹⁴²Nd target at the velocity filter SHIP. The evaporation residues were separated in-flight and subsequently identified on the basis of recoil-a, recoil-α&gamma/X-ray and excitation function measurements. Improved data on the αdecay of ^188,90Bi were obtained and a number of new low-lying excited states in the daughters ^184,186T1 were observed. An intruder, presumably 10 state was identified in ¹⁸⁴T1, extending the systematics of such states in the odd-odd Tl nuclei beyond the neutron mid-shell at N =104. Some technical aspects of experiment at recoil separators are also discussed. [ABSTRACT FROM AUTHOR]