Nuclear level density and γ-ray strength function of 63Ni

The nuclear level density (NLD) and gamma-ray strength function (gamma SF) of 63Ni have been investigated using the Oslo method. The extracted NLD is compared with previous measurements using particle evaporation and those found from neutron resonance spacing. The gamma SF was found to feature a strong low-energy enhancement that could be explained as M1 strength based on large-scale shell model calculations. Comparison of gamma SFs measured with the Oslo method for various Ni isotopes reveals systematic changes to the strength below 5 MeV with increasing mass.

Automated summary

This study investigates the nuclear level density (NLD) and gamma-ray strength function (gamma SF) of 63Ni using the Oslo method. The results are compared with previous measurements and neutron resonance spacing. The study finds a strong low-energy enhancement in the gamma SF, which can be explained by M1 strength based on large-scale shell model calculations. Additionally, systematic changes in the strength below 5 MeV are observed with increasing mass in various Ni isotopes.