Development of a Compact Multi-Analyzer System for Triple Axis Spectoscopy

Thermal neutron scattering is an extremely powerful technique for investigating the structure and properties of materials at the atomic level. By using inelastic neutron scattering, the fundamental excitation spectra within the material can be measured. However the cross sections for inelastic neutron scattering are extremely small, and, consequently, intense neutron sources are required for such measurements. This project will develop a Compact Multi-Analyzer System (CMAS) that has the potential to increase the effective count rate in such inelastic measurements by a factor of up to 16 times. The CMAS can be retro-fitted to existing Triple Axis Spectrometers, used at reactor neutron sources to carry out these measurements, to provide a highly cost-effective way of increasing the count rate. The compact nature of the CMAS is afforded by the innovative use of recently developed ¿solid state collimators,¿ which are based on the use of high transmission single crystal silicon wafers coated with layers of gadolinium (highly neutron absorbing) and Ni/Ti supermirror (highly neutron reflecting). Commercial Applications and other Benefits as described by the awardee: Phase I will demonstrate that the analyzer crystals in the compact multi-analyzer design can be accurately and reproducibly positioned and that it is feasible to construct a fanned array of solid state collimators.