Proton emission from drip-line nuclei ¹⁵⁷Ta and ¹⁶¹Re

Proton radioactivities from ¹⁵⁷Ta and ¹⁶¹Re are reported. Fusion-evaporation residues from the reaction of 270 MeV ⁵⁸Ni ions on ¹⁰²Pd and ¹⁰⁶Cd targets were separated according to M/Q and implanted into a double-sided silicon strip detector. One line from ¹⁵⁷Ta was observed with a proton energy of 927(7) keV [t_1/2=10.1(4) ms, b_p=3.4(12)%] from the πs_1/2 ground state. A new alpha decay transition with energy 6117(4) keV was also observed from this state. Two proton lines from ¹⁶¹Re were observed with energies 1192(6) keV [t_1/2=0.37(4) ms, b_p=100(7)%] and 1315(7) keV [t_1/2=16(1) ms, b_p=4.8(6)%] from the πs_1/2 and πh_11/2 states, respectively.