Several improvements have been made in the gamma scintillation counter (GSC). The Model V gamma scintillation counter uses a canned thallium activated sodium iodide crystal as a detector. Although the electronic components remain unchanged, a modification of the sample support has been made to improve reproducibility of geometry. To assure comparable results between various counters, they must be operated at the same energy threshold and counting yield. Methods have been developed to assure operation at a preferred energy threshold of 0.1 Mev and an arbitrarily fixed counting yield of 3.36% for Cs-Ba-137. Partial pulse height discrimination against U 237 is also accomplished.

The annealing or heat treatment of uranium in any medium other than a good vacuum or purified helium atmosphere, will lower the room temperature properties of ultimate strength, hardness and elongation. In general, the elongation of vacuum annealed uranium exceeds considerably the elongation of air or salt annealed uranium. Any annealing medium which permits contact of the uranium metal with atmospheric gases tends to produce low elongation and ductility and a lowering of the ultimate strength. The above is true for uranium in any solid form, whether it is rolled sheet, cast bars or plates, rolled rod, or extruded shapes. Annealing in the molten salt bath (65% potassium carbonate and 35% lithium carbonate), which is used by Los Alamos and other laboratories concerned with the fabrication of uranium, produces the lowest elongation or ductility and ultimate strength when compared to similar properties of metal annealed in the other media examined. Mass spectrometer analyses of the dissolved gases present in high ductility and low ductility uranium indicate that dissolved hydrogen is probably the chief cause of low physical properties.