| Summary: | The design and construction of a high intensity, thermal energy molecular beam apparatus is described. The system has been used to investigate the spatial distribution of molecules scattered from stainless steel targets with a range of surface finishes. The results indicate marked deviations from cosine scattering, which can be related to the surface finish of the target. The consequences of these results are discussed. Methods of theoretically predicting the spatial distribution of molecules scattered from rough surfaces are reviewed. The performance of the accumulation type of detector used for the majority of the scattering experiments is assessed, with particular reference to the gain and directional properties. The effects of detector misalignment of the experimental detector have been computed and the results are presented. A new type of high sensitivity flow-through molecular beam detector is described. Two versions of the detector have been developed; one for time-of-flight studies where good time resolution is essential, the other for applications where the highest ionisation efficiency is required. It is considered that these detectors will have a wide application in the field of molecular beam detection.
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