MOUND LABORATORY MONTHLY PROGRESS REPORT FOR FEBRUARY 1961

A survey and re-evaluation of previous work on polyurethane and polyurethane--epoxy copolymer systems was initiated to determine which phases are more productive than others. The effects of varying excess polyol content were studied. Work was carried out to define the amounts of butamediol that the system Adiprene L-213-ferric acetyl acetonate can tolerate and still be thoroughly cured. An experimental diallyl phthalate formulation was made and tested. A survey is being made of potential sources of kilogram quantities of Th/ sup 2//sup 3//sup 0/ in the United States. Analyses of various samples indicated concentrations almost three times as great as previously reported. The half-life of Rain was recalculated to include new data, and the results are reported as a function of the resolution time of the gas flow proportional counter. A method is being developed for determining the coincidence correction in porportional alpha counters by following the decay of a short-lived isotope. Additional determinations were made on the density of liquid cerium by the vacuum pycnometer method using tantalum pycnometers of about 0.5 cm/sup 3/ capacity. The viscosity of molten plutonium metal was investigated from 648 to 950 deg C with a cup viscometer. The construction of the hightemperature colorimeter was continued. Work was continued on the fabrication of plutonium-bearing glass fibers. (M.C.G.