A high temperature, high pressure cell for time-of-flight neutron scattering

A high temperature, high pressure cell for neutron scattering studies and capable of achieving 1100 K and 1.2 GPa is described. This cell is a modification of the McWhan clamped cell design (D.B. McWhan et al., Rev. Sci. Instr. 45 (1974) 643), adapted to incorporate a graphite heating element and optimised for time-of-flight (fixed geometry) neutron scattering techniques. Preliminary measurements are shown using standard samples for calibration as well as a profile refinement of data from an α-PbF2 sample within the cell at ambient temperature and pressure to confirm the effectiveness of cell absorption corrections. This refinement produced reliable structural parameters which were consistent with those obtained under optimal conditions. A further measurement from a high pressure high temperature disordered phase of CuCl with clear diffuse scattering is also shown.