Abstract
The first reported measurements of the decay, half-life, and mass of are presented. The new activity was produced by the reaction using 41-MeV incident ions, and was transferred pneumatically to a remotely located station where delayed rays and rays were counted with Ge(Li) and NE 102 detectors, respectively. -ray energies (in keV) and relative intensities for the daughter transitions are 621.81±0.30 (9.94±0.65), 752.23 ±0.30 (18.5±0.8), 1564.49±0.30 (17.3±1.6), 1694.73±0.30 (58.9±1.6), and 2316.64±0.40 (72.8±1.8). The excitation energies (in keV) and relative branching intensities are 752.24±0.30 (<3.0), 1694.78±0.30 (49.0±1.7), and 2316.73±0.40 (100±2.5). A tentative - ray transition to a state at keV is also observed. Upper limits on the strength of some possible -ray transitions following decay to higher levels are given. decays with a half-life of 644±25 msec. By measuring the energy spectra of rays populating the second and third excited states of the mass excess of has been measured to be -15008±100 keV. The mass excess of has been remeasured by a similar technique to be -24 550±90 keV, and this value has been used to revise previous predictions for the masses of and . The masses of several and nuclides in the shell are compared with theoretical estimates. The -decay measurements for are shown to be in poor agreement with simple collective-model calculations, and in good agreement with recent detailed shell-model calculations.
- Received 2 February 1973
DOI:https://doi.org/10.1103/PhysRevC.7.2409
©1973 American Physical Society