Proton emission from drip-line nuclei157Taand161Re

Proton radioactivities from ${}^{157}\mathrm{Ta}$ and ${}^{161}\mathrm{Re}$ are reported. Fusion-evaporation residues from the reaction of 270 MeV ${}^{58}\mathrm{Ni}$ ions on ${}^{102}\mathrm{Pd}$ and ${}^{106}\mathrm{Cd}$ targets were separated according to $M/Q$ and implanted into a double-sided silicon strip detector. One line from ${}^{157}\mathrm{Ta}$ was observed with a proton energy of 927(7) keV [$t_{1/2}=10.1\mathrm{}\left(4\right)\mathrm{}$ ms, $b_p=3.4\mathrm{}\left(12\right)\mathrm{}$%] from the $\pi s_{1/2}$ ground state. A new alpha decay transition with energy 6117(4) keV was also observed from this state. Two proton lines from ${}^{161}\mathrm{Re}$ were observed with energies 1192(6) keV $[t_{1/2}=0.37\mathrm{}(4)\mathrm{}$ ms, $b_p=100\mathrm{}\left(7\right)\mathrm{}$%] and 1315(7) keV $[t_{1/2}=16\mathrm{}(1)\mathrm{}$ ms, $b_p=4.8\mathrm{}\left(6\right)\mathrm{}$%] from the $\pi s_{1/2}$ and $\pi h_{11/2}$ states, respectively.