Progress report, Chemistry and Materials Division

Laser radiation has been used to anneal damage created by implantation of arsenic ions into silicon single-crystal wafers. The threshold for recovery of lattice order, as measured by ion channeling methods, appeared at an energy density of 1.2 J.cm-2. Deuterium-enriched water has been recovered for the first time in visible amounts from a process based on laser photolysis. High performance liquid chromatography has been applied to the determination of U(VI) in ground water and urine. Results with low ground water concentrations were judged to be successful, while only limited success was achieved with urine. The first analyses in support of the production of (Th,Pu)O2 fuel elements were completed successfully. Experiments performed during the quarter have shown that cracking of Zr-2.5 percent Nb alloy by gaseous hydrogen is inhibited by traces of oxygen. It was found that there was no inhibition by helium in the absence of trace oxygen. Excellent agreement has been obtained between the growth and creep constants derived from ion-irradiated cantilever beam specimens and those from reactor irradiation of the same materials. (O.T.)