The local atomic and magnetic structure of a powder crystalline sample of MnO has been modelled for a wide range of temperatures (10-1100 K) by fitting neutron powder diffraction data using the reverse Monte Carlo technique (RMC). This method allows simultaneous and self-consistent fitting of Bragg and diffuse scattering of both nuclear and magnetic origin and so the fitted models contain information not only on long-range order but also disorder. Results show that the method as applied to MnO produces models that give correct values for different known physical properties so that prospects for modelling less simple materials are good.

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The Studsvik high resolution, low background time-of-flight facility has been used to obtain a comprehensive set of differential neutron scattering cross sections for carbon at the neutron energies 16.5, 17.6, 18.7, 19.8, 20.9, 21.6 and 22.0 MeV. Angular distributions in the range 10-160" have been measured for elastic scattering, and also for inelastic scattering from the levels at 4.44, 7.65 and 9.64 MeV. Angle integrated cross sections have been determined by fitting Legendre polynomial expansions to the differential data. Partial kerma factors for elastic and inelastic (4.44MeV level) scattering have been deduced from these fits. Analyses in terms of a spherical optical model as well as in terms of the coupled-channels formalism with a deformed potential have provided information for cross section and partial kerma factor calculations also outside the measured energy range.