Scintillating glass fiber neutron sensors: 1, Production and optical characterization

摘要

The production and optical characterization of cerium-doped lithium silicate scintillating fibers used as thermal neutron detectors are discussed. The bulk glass continuing enriched (sup 6)Li is produced starting from high-purity commercial materials which are further purified at Pacific Northwest Laboratory (PNL). The fibers are drawn at PNL in a hot down-draw process. The fibers are coated with a silicone polymer that serves as both an optical cladding and a physical buffer coat. Optical characterization has included measurements of light output as a function of glass composition, optical attenuation lengths, and fluorescence lifetimes. Fibers have been prepared in our laboratory with as-drawn attenuation lengths (l/e distance) in excess of 2 meters over sub-meter distances.