It was found that hydrogen is introduced into uranium during process-annealing in a fused salt bath. The increased hydrogen content reduces the tensile elongation and general formability of the metal. The partial removal could be affected by annealing in argon, helium, or nitrogen, and better by annealing in high vacuum at temperatures above 450°C. The effect of the hydrogen content on the tensile properties was confirmed by annealing in hydrogen. Tensile properties, the hydrogen content, and certain X-ray results after each annealing treatment are presented and briefly discussed

The stability of a pinched plasma equilibrium with a longitudinal magnetic field superimposed on the characteristic azimuthal magnetic field of the pinch current is studied theoretically. The linearized solutions are developed as helical perturbations of the plasma surface, and the behavior of these is given for the different cases of uniform longitudinal, longitudinal field zero inside the plasma, and for helices of the same and opposite sense to the helix which describes the total magnetic field. Very approximately, the conclusions are: that the longitudinal field has the effect of stabilizing short-wave perturbations, but that some long-wave perturbations remain unstable no matter how large the externally imposed longitudinal magnetic field.

The vapor pressure of nickel carbonyl was determined with material obtained by laboratory preparation with CO and Ni powder and by purifying commercial nickel carbonyl. The observed vapor pressure data were used in the derivation of the following equations which express the vapor pressure, P, of liquid nickel carbonyl and the sublimation pressure, P/sub s/, of the solid, respectively, as a function of the absolute temperature, T: log P = 7.88431578/T and log P/sub s/ 10.1897-2173/T. The average heat of vaporization is calculated to be 7.22 plus or minus 0.01 kcal per mole and the molecular heat of sublimation of Ni(CO)/sub 4/ is 9.94 plus or minus 0.11 kcal. Extrapolation to 760 mm Hg gives a boiling point of 42.2 deg C. The melting point of purified nickel carbonyl occurred at -17.2 deg C. The sensitivity of the melting point to the effect of impurities was demonstrated with commercial nickel carbonyl which melted at-19.4 deg C before purification, at --18.3 deg C after distillations at 0 deg C, and at -17.2 deg C after sublimation at -25 deg C. The vapor pressure of liquid nickel carbonyl at 0 deg C is of little value in evaluation of the purity of …