Eur. Phys. J. A (2003) 18: 55-64
https://doi.org/10.1140/epja/i2003-10051-1

OriginalPaper

$\alpha$-decay spectroscopy of light odd-odd Bi isotopes - II: ¹⁸⁶Bi and the new nuclide ¹⁸⁴Bi

¹ Department of Physics, Oliver Lodge Laboratory, University of Liverpool, L69 7ZE, Liverpool, UK
² Gesellschaft fur Schwerionenforschung, Planckstrasse 1, D-64291, Darmstadt, Germany
³ Instituut voor Kern- en Stralingsfysica, University of Leuven, Celestijnenlaan 200 D, B-3001, Leuven, Belgium
⁴ Vakgroep Subatomaire en Stralingsfysica, University of Gent, B-9000, Gent, Belgium
⁵ Institut für Physik, Johannes Gutenberg-University, Staudingerweg 7, D-55099, Mainz, Germany

^* e-mail: aan@ns.ph.liv.ac.uk

Abstract

Alpha-decay of the new nuclide ¹⁸⁴Bi has been studied in the complete-fusion reaction ⁹³Nb(⁹⁴Mo, 3n)¹⁸⁴Bi at the velocity filter SHIP. The evaporation residues were separated in-flight and subsequently identified on the basis of recoil-$\alpha$, recoil-$\alpha$-$\gamma$ analysis and excitation functions measurements. Two $\alpha$-decaying isomeric states in ¹⁸⁴Bi with half-life values of 13(2) ms and 6.6(1.5) ms were identified. The $\alpha$-branching ratio of ¹⁸⁰Tl was deduced for the first time as $b_\alpha = (2 --12)\%$. Improved data on the fine-structure $\alpha$-decay of ¹⁸⁶Bi were obtained in the ⁹³Nb(⁹⁵Mo, 2n)¹⁸⁶Bi reaction. A similarity of the decay energies and half-life values of ^184,186Bi is pointed out and a possible explanation for this effect is suggested.