Technical report with short reports on (1) Heavy water analysis and standardization, and Specific gravity of pure D2O; (2) Homogenous exponential experiment; (3) Recombination of pile gases; (4) Slurry pumping studies; and (5) Electron microscope laboratory.

Technical report. The object of the research is to determine the procedure and equipment for the preparation of U233 on a semi-works scale. The general proposed procedure is that thorium carbonate in aluminum cans will be irradiated with pile neutrons. The Pa233 resulting from neutron absorption the Th232 and the decay of Th233 will be extraction from 99% of the thorium and the natural U in thorium by MnO2 precipitations. The Pa233 will then be allowed to decay to U233 which in turn will be isolated from the remaining Th and partially decayed Pa233 by ether extraction.

The following represents a summary of calculations on the multiplication constant of homogeneous mixtures of uranium and different moderators. These calculations were made possible by Fermi's determination of the age of neutrons and by the extrapolation to higher scattering cross-sections of the resonance absorption of uranium as measured by C. Creutz. According to Fermi, the former quantity is 120 sq. cm. The latter is given in the two attached graphs. The first (Fig.1) of these goes as high as a scattering cross-section of 70 x 10-24 cm.2 per uranium atom, and its highest point is taken from a measurement of Cruetz's in which a mixture of U3O8 and graphite was used.