Reinvestigation of the Direct Two-Proton Decay of the Long-Lived Isomer 94Agm [0.4 s, 6.7 MeV, (21+)]

An attempt to confirm the reported direct one-proton and two-proton decays of the (21+) isomer at 6.7(5) MeV in Ag-94 has been made. The 0.39(4) s half-life of the isomer permitted use of a helium-jet system to transport reaction products from the Ca-40 + Ni-nat reaction at 197 MeV to a low-background area; 24 gas Delta E-(Si)E detector telescopes were used to identify emitted protons down to 0.4 MeV. No evidence was obtained for two-proton radioactivity with a summed energy of 1.9(1) MeV and a branching ratio of 0.5(3)%. Two groups of one-proton radioactivity from this isomer had also been reported; our data confirm the lower energy group at 0.79(3) MeV with its branching ratio of 1.9(5)%.