With the use of an on-line mass separator, electron capture (EC) and ${\mathrm{\beta }}^{+}$ decay of the direct proton emitter ${}_{}{}^{147}{}_{}{}^{}\mathrm{Tm}$ was identified in a series of ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$${+}^{92}$Mo irradiations. Characteristic Er Kα x rays and an 80.9-keV γ ray were observed to decay with the half-life of ${}_{}{}^{147}{}_{}{}^{}\mathrm{Tm}$. The 80.9-keV γ ray is proposed to be the transition connecting the first-excited (${\mathit{d}}_{3/2}$) and ground (${\mathit{s}}_{1/2}$) neutron-hole states in ${}_{}{}^{147}{}_{}{}^{}\mathrm{Er}$. The ${}_{}{}^{147}{}_{}{}^{}\mathrm{Tm}$ (EC+${\mathrm{\beta }}^{+}$)-decay strength was deduced from K x-ray and annihilation radiation intensities. A comparison of this strength with the intensity of the 1.045-MeV proton peak leads to a ${}_{}{}^{147}{}_{}{}^{}\mathrm{Tm}$ direct-proton-decay branch of 15(5)%.

• Received 12 November 1992

DOI:https://doi.org/10.1103/PhysRevC.47.1804