Adding neutron guides to existing and proposed thermal neutron research facilities has great economic benefit. Supermirror guides, because of their ability to conduct higher energy, shorter wavelength neutrons, are particularly attractive. Phase I demonstrated various improvements in supermirror construction technique. Specifically, using "self-leveling" intermetallic compounds and mechanical strain built into the layers significantly improved the degree of reflectivity that can be obtained in a single guide wall reflection for mirrors built to twice (2x) the critical angle of nickel coatings. Present limitations were explored by building test mirrors out to 5x. Phase II will (1) extend the useful range of high reflectivity to shorter wavelengths and higher critical angles by modifying Phase I materials and algorithms, (2) improve the capability to construct larger superrnirror neutron guide segments at higher speeds by modifying the sputtering machine, and (3) further develop those processing issues that will maximize uniformity and minimize production cost.Anticipated Results/Potential Commercial Applications as described by the awardee:Increased angular acceptance for existing and proposed neutron guides multiplies the use of thermal neutron sources with a minimal increase in expense. The availability of mirrors and collimators will also benefit neutron and x-ray instrumentation such as bomb detection by thermal neutron activation (TNA) and oil well down-pipe TNA. Room temperature thermal neutron operation is particularly desirable.
