Polarization and Differential Cross Section for Neutrons Scattered fromLi6andLi7

The polarization and differential cross section for neutrons scattered from ${\mathrm{Li}}^6$ and ${\mathrm{Li}}^7$ have been measured at several angles for neutron energies from 0.2 to 2.0 MeV. The measurements indicate that for energies from about 0.5 to 2.0 MeV both ${\mathrm{Li}}^6$ and ${\mathrm{Li}}^7$ are useful as polarization analyzers. Attempts to explain both the differential cross section and polarization results simultaneously, for the $n$-${\mathrm{Li}}^7$ scattering in terms of only a few levels in the compound nucleus ${\mathrm{Li}}^8$, are only partially successful. Furthermore, preliminary calculations based on an optical-model interaction for both the $n$-${\mathrm{Li}}^6$ and $n$-${\mathrm{Li}}^7$ scatterings do not lead to a completely successful interpretation of all the results.