A measurement was made of the angular distribution of neutrons from the ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}(p, n){}_{}{}^{13}{}_{}{}^{}\mathrm{N}(\mathrm{g}.\mathrm{s}.\mathrm{})$ from which the total cross section leading to the ground state of ${}_{}{}^{13}{}_{}{}^{}\mathrm{N}$ was determined. At the same time, the determination of the ${}_{}{}^{13}{}_{}{}^{}\mathrm{N}$ activity was made. The ratio of the reaction cross sections at 22.8 MeV determined from ${}_{}{}^{13}{}_{}{}^{}\mathrm{N}$ activation to the yield of the ground state neutron group is 1.06±0.07. Thus there is no significant competition in the decay of excited states by $\gamma$ emission with particle emission. This result implies that the reaction can be used as a convenient fast neutron calibration source.

NUCLEAR REACTIONS $\frac{d\sigma }{d\Omega }$ ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}(p, n){}_{}{}^{13}{}_{}{}^{}\mathrm{N}(\mathrm{g}.\mathrm{s}.\mathrm{})$, $E=16.3, 22.8$ MeV. Comparison of neutron yield and ${}_{}{}^{13}{}_{}{}^{}\mathrm{N}$ activity.

• Received 29 January 1975

DOI:https://doi.org/10.1103/PhysRevC.11.2099