Nuclear Science and Engineering / Volume 143 / Number 2 / February 2003 / Pages 164-176
High-energy transport codes for the design of accelerator-driven systems such as the Spallation Neutron Source use nuclear reaction models as the incident particle, and the secondary particles are transported through various materials. These reaction models are computationally fast but are unreliable at energies below ~200 MeV. As a partial remedy, an evaluated cross-section library up to 150 MeV known as LA150 was developed by international cooperation and made available for such design work. In the present project we have been developing a model code suitable for improving LA150 and extending it to higher energies. This new model code combines microscopically the semiclassical results of an intranuclear-cascade model with the spin-dependent counterparts of a preequilibrium Hauser-Feshbach model. To achieve this microscopic combination, an approximation, explained in this paper, is needed to add spin distributions to the semiclassical excitation spectra in every residual nuclide. The initial capability of this code is demonstrated by comparisons with experimental production cross sections of the radioisotopes 56Co, 55Co, 54Mn, 52Mn, 52Fe, 51Cr, 48Cr, 48V, 47Sc, and 46Sc induced by proton projectiles on Fe from reaction thresholds to 3 GeV. The overall agreement of our calculated results with experimental data looks very good in view of the 29 contributions in recent model code intercomparisons with measurements.