Incoherent neutron scattering from solid mixtures of orthohydrogen and parahydrogen

The cross section for incoherent scattering of neutrons from orthohydrogen molecules in solid H2 is reexamined at large o-H2 concentration c. The use of angular momentum autocorrelation functions calculated by means of a diagrammatic technique valid at large c yields a quasielastic-cross-section linewidth approximately proportional to c for 0.5c<1.0. The results presented here for the cross section are expected to be superior to those we obtained earlier.