Preequilibrium emission in (p, x n) reactions on palladium isotopes

Abstract

Energy spectra of neutrons from the lO4, 105,106, lO8,110pd(p ' xn) reactions at E v = 26.1 MeV have been measured using the time-of-flight technique with good overall energy resolution (<250 keV). The hard part of angle-integrated spectra corresponding to low residual excitations (U<6MeV) exhibits pronounced structure varying from isotope to isotope. The observed structure can be reasonably well described by preequilibrium-model calculations with two-quasiparticle state densities for proton-particle neutron-hole configurations based on Nilsson-model single-particle levels instead of equidistant ones. The influence of nuclear deformation and pairing on preequilibrium particle emission is explored.