Abstract
Isotopes of rutherfordium () were produced in irradiations of targets with beams. Excitation functions were measured for the , and exit channels. Production of in the exit channel with a cross section of pb was observed. -decay of was observed for the first time with an -particle energy of 9.05 ± 0.03 MeV and an total-decay branching ratio of 0.31 ± 0.11. In , the electron capture/total-decay branching ratio was measured to be . The measured half-lives for , , and were ms, s, and ms, respectively, in agreement with literature data. The systematics of the -decay -values and of the partial spontaneous fission half-lives were evaluated for even-even nuclides in the region of the deformed shell. The influence of the shell on the -decay -values for rutherfordium was observed to be similar to that of the lighter elements (). However, the shell does not stabilize the rutherfordium isotopes against spontaneous fission, as it does in the lighter elements ().
- Received 10 December 2007
DOI:https://doi.org/10.1103/PhysRevC.77.034603
©2008 American Physical Society