5 - LS-Coupled, Localized Electron, Magnetic Scatter of Neutrons

Abstract

The neutron partial differential cross section for neutron scatter from a magnetic crystal is presented in this chapter. First, the partial differential cross section for neutron scatter from a magnetic crystal, which assumes the Heitler–London model, LS coupling, and a quenched crystal, is discussed. The magnetic form factor is described, and with these three assumptions, evaluation of the thermal average of initial state, unpaired, atomic electron positions, yields a partial differential cross section expression, which is then extended to include unquenched scattering atoms. The partial differential cross section is then expressed by the coherent intermediate correlation function, which is separated into elastic and inelastic components. This allows the partial differential cross section to be separated into the following terms: (1) nuclear elastic scatter and magnetic elastic scatter, (2 ) inelastic nuclear scatter and elastic magnetic scatter, (3) inelastic magnetic scatter and elastic nuclear scatter, and (4) inelastic nuclear scatter and inelastic magnetic scatter.