Reinvestigation of the decay properties of Bh261,262 at the gas-filled recoil separator SHANS2

Résumé fourni par la source

The isotopes $^{261,262}\mathrm{Bh}$ were reinvestigated by using the cold fusion reaction $^{54}\mathrm{Cr}+^{209}\mathrm{Bi}$. The evaporation residues were separated by the gas-filled recoil separator SHANS2 (Spectrometer for Heavy Atoms and Nuclear Structure-2) and identified by means of the recoil-$\ensuremath{\alpha}$-correlation method. The $\ensuremath{\alpha}$-decay properties of $^{261,262}\mathrm{Bh}$ were measured and the results are consistent with the previously reported values. Based on the measured half-lives, the existence of two distinct states of $^{262}\mathrm{Bh}$ was confirmed, whereas $^{261}\mathrm{Bh}$ lacked any isomer with $\ensuremath{\alpha}$-decay properties. Two spontaneous fission events potentially from $^{262}\mathrm{Bh}$ and/or $^{261}\mathrm{Bh}$ were detected and the production cross sections at beam energies of 264.1 and 270.4 MeV were obtained.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.