The fusion reaction Se-74 + Cd-106 --> Pb-180-* at a compound nucleus excitation energy E(x) congruent-to 40 MeV, has been used in a search for the decay of the unknown nucleus Tl-177. Evaporation residues were velocity and mass analysed prior to implantation into a position sensitive silicon surface barrier detector. No evidence was discovered for the proton or alpha-decay of Tl-177 for a cross-section > 10(-5)+10 nb. This indicates either that T1-177 decays too rapidly (t1/2 < 1-mu-s) by proton emission for the decay to be detected, or that Tl-177 is produced with a cross-section less than the limit established in the present experiment. The following nuclear decay half-lives were measured with improved accuracy; Hg-177 (t1/2 = 130 +/-5 ms), Hg-178 (t1/2 = 250+/-25 ms) and Au-177 (t1/2 = 1180+/-70 ms). The experiment also provided the first direct confirmation of the correct mass assignment of the alpha-decay, E-alpha = 6.26 MeV, to the decay of Au-176. Two additional half-life measurements of proton-rich Osmium isotopes are also presented from a previous similar experiment; Os-165 (t1/2 = 73+/-8 ms) and Os-166 (t1/2 = 194+/-17 ms).
|Number of pages||2|
|Journal||Zeitschrift fur physik a-Hadrons and nuclei|
|Publication status||Published - 1991|