ISOMERIC PROTON EMISSION FROM THE DRIP-LINE NUCLEUS TA-156

A new proton emission line has been observed in the nucleus 156Ta usin g the fusion reaction Ni-58 + Pd-102 --> 160W, E(x) almost-equal-to 6 1 MeV. The line has a proton energy E(p) = 1103 +/- 12 keV correspondi ng to a Q value Q(p) = 1110 +/- 12 keV, and a half-life of 320 +/- 80 ms. The proton line is assigned to a approximately 3% decay branch fro m a high spin pih11/2nuf7/2 isomeric state on the basis of systematics . The subsequent implications for level ordering in this region beyond the proton drip line are discussed.