Single-charge and row-charge subsurface cratering experiments were performed to learn how close-spacing enhances single-crater dimensions. Our first experimental phase established cratering curves for 60-lb charges of the chemical explosive. For the second phase, to be described in a subsequent report, the Row-cratering experiments were designed and executed. This data report contains excavated dimensions and auxiliary data for the single-charge cratering experiments. The dimensions for the row-charge experiments will be in the other report. Significant changes in the soil's water content appeared to cause a variability in the excavated dimensions. This variability clouded the interpretation and application of the cratering curves obtained.

Two approaches were made to studies on genetic recombination in Chinese hamster cells: cytogenetics and the synthesis of a hybrid cell line containing two noncomplementing nutritional mutants, presumably in the same cistron, that can be used to detect crossing over to produce nutritional independence. The cytogenetic approach was used to characterize existing mutants and to study new mutants. It is also being used to characterize the parents of the hybrids and the hybrids themselves with a view that prototrophic recombinants selected biochemically will also show recombination cytologically. (HLW)

The production of UF/sub 6//sup -/ by reaction of a collimated stream of fluorine gas with a resistively heated uranium wire was studied at temperatures from 870 to 1020/sup 0/C and pressures less than 10/sup -3/ torr. At these temperatures below the uranium melting point, the formation of UF/sub 3/ intermediate on the uranium surface resulted in low UF/sub 6//sup -/ yields. The kinetic energy of the UF/sub 6//sup -/ ion was on the order of thermal energies. The work function of uranium was measured to be 4.20 +- 0.14 eV.