Differential Elastic Scattering Cross Section for Neutrons on Nitrogen

Two independent methods were used to measure the angular distribution for elastic scattering of neutrons from nitrogen in the neutron energy range from 0.80 to 2.36 Mev. The scattered neutrons were counted directly in order to obtain the absolute differential cross section at four neutron energies. These curves provide information on the potential scattering for energies below 1.54 Mev. The second technique, which observed the recoil nitrogen nuclei, allowed a study of scattering at the resonances. In this manner parities were established for levels in ${\mathrm{N}}^{15}$ as follows: The 1.120, 1.401, 1.595, and 2.25-Mev levels have odd parity; the 1.779-Mev level has even parity and a tentative assignment of even parity was made for the 1.350-Mev level. $J$-values associated with resonances at 1.12 and 2.25 Mev were each assigned to be $\frac{3}{2}$ rather than the values favored in the literature.