Preequilibrium (n,n') cross sections on nuclei around atomic number 50 at E/sub n/ = 14.1 MeV

The energy spectra of neutrons emitted from 14.1-MeV-neutron-induced reactions on Ag, Cd, In, Sn, Sb, and Te were measured at 700 in order to investigate the shell and odd-even effects in the preequilibrium (n,n') process. The cross sections integrated over the outgoing energies of 7--10 MeV, where the preequilibrium process is dominant, increased monotonically with increasing atomic numbers of all scatterers except Te. The results of calculations based on the exciton model showed an underestimation in 7--10 MeV only for Te. This underestimation could be explained by taking into account the contribution from the collective excitations of the low energy octupole resonance by the direct process. As a result, it was found that there were no appreciable shell and odd-even effects in the preequilibrium (n,n') process that leaves the residual nucleus into the continuum region