The ¹⁴N(n, xγ) Reaction for 5.8 ≤ E_n ≤ 8.6 MeV

We have obtained gamma-ray spectra for the reactions ¹⁴N(n, n′γ)¹⁴N, ¹⁴N(n,þγ)¹⁴C, and ¹⁴N(n, αγ)¹¹B for incident mean neutron energies E_n = 5.8, 6.4, 6.8, 7.4, 8.0, and 8.6 MeV. The gamma rays were detected using a coaxial Ge(Li) detector of 30 cm³ active volume. The detector was placed at 55 and 90° with respect to the incident neutron direction, and was 77 cm from the sample; time-of-flight was used with the gamma-ray detector to discriminate against pulses due to neutrons and background gamma radiation. The sample was 100 g of Be₃N₂ in the form of a right circular cylinder. Data were also obtained using a 75-g Be sample to provide an estimate of the background. The incident neutron beam was produced by bombarding a deuterium-filled gas cell with the pulsed deuteron beam of appropriate energy from the ORNL 6-MV Van de Graaff. The resulting neutron beam was monitored using a scintillation counter; a time-of-flight spectrum from this detector was recorded simultaneously with the gamma-ray data. These data have been studied to obtain absolute cross sections for production of gamma rays from ¹⁴N for the incident neutron energies quoted above. The cross sections have been compared, where possible, with previously measured values with good agreement. However, there are several important differences with previous data and these are discussed. In particular, summing the partial cross sections yields a value for the total nonelastic cross section that is approximately half of the total nonelastic cross section obtained from the difference between the total cross section and the total elastic cross section.