The γ-radiation has been investigated for 63Ni produced by cold neutron capture in an enriched 62Ni sample. The 315 γ-rays produced were placed in a 63Ni level scheme, in which 272 placements are new. We determined the excitation energies with 0.2-0.8 keV error and the branching ratios of 62 bound levels in 63Ni, including 30 new levels. The Q-value of the 62Ni(n, γ) 63Ni reaction amounts to 6837.75 ± 0.18 keV. A large-scale shell-model calculation was performed that included the four single-particle orbits of 0f 7/2, 1p 3/2, 0f 5/2, and 1p 1/2, assuming an inert 40Ca core for negative-parity states, and those of 1 p3/2, 0f 5/2, 1p 1/2, and 0g 9/2, assuming a 56Ni core for positive-parity states. The energies of the low-lying 63Ni states were successfully reproduced. A mean-field statistical-model calculation was also performed by using a self-consistent interaction between the Hartree-Fock + Bardeen-Cooper-Schrieffer method and the statistical calculation. The calculation result is consistent with the experimental level density of 63Ni.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)