Spin-orbit effects in the inelastic scattering of 12 MeV neutrons in carbon

The angular distribution and polarization of elastic and inelastic scattering of 12 MeV neutrons in carbon are investigated using the distorted wave approximation, assuming direct interaction in inelastic collisions. The introduction of a spin-orbit potential enables the same optical parameters to describe the elastic and inelastic scattering. Calculations are performed for spin-independent potentials and the results compared with those of Levinson and Banerjee. It is found that the neglect of a spin-orbit potential leads to inconsistent optical model parameters and poor fits at intermediate angles. The inelastic polarization predicted is very similar to the elastic polarization in the outgoing channel, although it is slightly smaller. Even larger discrepancies are found in the two-body potential when a spin-orbit potential is included. Extension of the theory to include collective motion may be necessary.