Polarization of 24-MeV Neutrons Elastically Scattered from C, Al, Fe, Sn, Pb, and Bi

Employing the 64% polarized neutron source from the $\mathrm{T}\mathrm{}\left(\mathrm{dn}\right)\mathrm{}{\mathrm{He}}^4$ reaction at 30° for an incident deuteron energy of 7.7 MeV, the angular dependence of the polarization for elastic scattering of 24-MeV neutrons from C, Al, Fe, Sn, Pb, and Bi has been measured from 20° to 70° in 5° steps. The "left" and "right" measurements are obtained by precessing the neutron spin magnetic moment plus and minus 90° with a suitably designed solenoid. The measured polarizations are in reasonable agreement with the optical-model predictions of Bjorklund and Fernbach, provided that the sign of the spin-orbit potential agrees with that deduced from the shell model. The magnitude of the spin-orbit potential (25 times Thomas) is in agreement with that deduced from fitting the proton polarization data.