ISOMERIC CROSS-SECTION RATIOS AND TOTAL CROSS SECTIONS FOR 59CO(N,2N)58G,MCO, 58NI(N,P)58G,MCO AND 59CO(GAMMA,N)58G,MCO REACTIONS

The isomeric ratios and excitation functions were measured for the 59Co(n, 2n)58Co reaction in the neutron energy range 12-18 MeV and for the 58Ni(n, p)58Co reaction in the neutron range 2-18 MeV. The isomeric ratio is also presented for the 59Co(γ, n)58Co reaction induced by photons from 30 MeV electron bremsstrahlung. The results are compared with the statistical-model predictions. Use was made of modified nuclear level density formulae based on the superconductivity theory, which account for the pairing and shell effects. In all cases investigated, the calculated isomeric ratios show good agreement with experimental data, whereas the calculated total cross sections do not agree with the measured values. The disagreement may be due to the fact that no account was taken of the gamma emission in competition with the neutron emission from the residual nucleus. © 1968.