Attempt to synthesize the proton-unbound Bi182,183 isotopes

The near-symmetric complete fusion reaction ⁷⁸Kr+¹⁰⁷Ag→¹⁸⁵Bi* was studied at the gas-filled recoil separator SHANS with an attempt to synthesize the extremely neutron-deficient proton-unbound 182,183Bi isotopes. No decay events which could be attributed to them were observed. The two- and three-particle evaporation residues 180,179Hg (αp, αpn) and 183,182Pb ($pn, p2n$) were identified. Their production cross sections have been measured at two bombarding energies. Based on the yields of 182,183Pb in the present work and the systematics of the ratios between the cross sections of p(x-1)n and $xn$ evaporation channels for the most neutron-deficient odd-Z nuclei above lead, the upper limits for the half-lives of 182,183Bi were estimated to be less than 0.30.16em0exs.