The 93Nb( n,2 n) 92 mNb cross section

Abstract

We report new measurements of the cross section for the 93Nb( n,2 n) 92 m Nb (10.15 d) reaction in the 14–19 MeV energ range. They are based on the known cross section for the 27Al( n, α) 24Na reaction. We also give revised results for two other sets of measurements (reported previously) of the 93Nb cross section in the 9–15 MeV energy range. The excitation function for the 93Nb( n,2 n) 92 m Nb reaction is known with sufficient accuracy in the 13.5–15.5 MeV range for its use as a secondary neutron-fluence monitor. The peak cross section in the 14.0–14.6 MeV range is 464 mb (±3% uncertainty). Outside the 13.5–15.5 MeV range, the uncertainty in the cross section is at least ±10%. We compare our results with other measurements reported for the 93Nb( n,2 n) 92 m Nb reaction.