Abstract

The new nuclides \(^{165}\mathrm{Pt}\) and \(^{170}\mathrm{Hg}\) were produced in the reactions \(^{92}\mathrm{Mo}(^{78}\mathrm{Kr},5n)\) and \(^{96}\mathrm{Ru}(^{78}\mathrm{Kr},4n)\) at bombarding energies of 418 MeV and 390 MeV, respectively. For \(^{170}\mathrm{Hg}\) an α-particle energy of \(E_{α} = 7590(30)\) keV and half-life of \(t_{1/2} = 0.08^{+0.40}_{−0.04}\)ms were deduced, while for \(^{165}\mathrm{Pt}\) the corresponding values were 7272(14) keV and \(0.26^{+0.26}_{−0.09}\)ms. Comparison of the reduced α-decay widths with systematics indicates that both α decays are unhindered. Although combining the measured α-decay Q values with extrapolated masses suggests that both new nuclides are unbound to two-proton emission by more than 1 MeV, their α-decay half-lives are too short for this decay mode to compete. Improved data were also obtained for \(^{166,167}\mathrm{Pt}\), produced via the \(^{96}\mathrm{Ru}(^{78}\mathrm{Kr},α4n)\) and \(^{96}\mathrm{Ru}(^{78}\mathrm{Kr},α3n)\) reactions at bombarding energies of 390 MeV and 418 MeV.