Energy levels and configurations in ⁹⁴Nb

In the high-energy thermal neutron capture gamma-ray spectrum of ⁹⁴Nb, 83 gamma rays were observed between 4500 keV, and the neutron binding energy determined here to be 7229.5 ± 1.5 keV. A total of 71 low-energy gamma rays was observed from 30 keV to 1500 keV. These and previous data were used to develop a decay scheme. The presence of states arising predominantly from the following configurations is proposed: πg_{frac(9, 2)} v (d_{frac(5, 2)})_{frac(5, 2)}³, πg_{frac(9, 2)} v (d_{frac(5, 2)})_{frac(3, 2)}³, π (p_{frac(1, 2)})^{- 1} (g_{frac(9, 2)})₀² v (d_{frac(5, 2)})_{frac(5, 2)}³ and, more tentatively, π (p_{frac(1, 2)})^{- 1} (g_{frac(9, 2)})₀² v (d_{frac(5, 2)})_{frac(9, 2)}³ and πg_{frac(9, 2)} v (d_{frac(5, 2)})₀² S_{frac(1, 2)}. Some preliminary assignments of spins and parities to other states have also been attempted. Calculations based on ⁹⁰Zr and ⁸⁸Sr cores both agree well with energies, spectroscopic factors and reduced M1 transition probabilities. The generally close agreement between the calculations involving different cores is surprising in view of the considerable differences in the two sets of wave functions. This is probably to be understood in terms of the ability of the effective nucleon-nucleon interaction to absorb the effect of configuration mixing.