Excited states in Nb91 from the Zr91(p,nγ)Nb91 reaction

In-beam γ-ray measurements of the excited states in Nb91 have been made using the reaction Zr91(p,nγ)Nb91 at incident proton energies between 3.0 and 6.3 MeV. Singles, threshold, and γ-γ coincidence measurements were made using Ge(Li) detectors and an on-line two-parameter data acquisition system. By these methods more than 70 γ rays associated with the deexcitation of levels in Nb91 have been observed. γ-γ coincidence spectra produced by gates on 12 of the stronger transitions were used along with a threshold experiment to identify 43 levels with energies up to 4.3-MeV excitation. 12 of these levels having energies of 1984, 2326, 2331, 2992, 3066, 3126, 3179, 3274, 3328, 3434, 3462, and 3636 keV had not been previously reported. Branching ratios are given along with a decay scheme for Nb91.