A comprehensive survey of the literature was made in an effort to identify nonmetallic materials of possible usefulness as liquid coolants. Materials having maximum melting points of 1000 deg F and boiling points of l200 deg F were considered, but boiling points above 2200 deg F were preferred. Melting points, boiling points, densities, heat capacities, and thermal conductivities were tabulated. Approximately 190 materials appeared to have melting and boiling temperatures in a suitable range. A paucity of thermal- conductivty and heat-capacity data prevented further estimates of suitability of all but nine of these materials. Of these nine nonmetallics, only sodium hydroxide appeared to offer possibilities when considered according to the NEPA formula. (M.C.G.)

The electrostatically deflected beam of the 184-inch cyclotron has been used with the stacked foil and absorber technique to determine the excitation functions for the following reactions: Th{sup 232}(p,6n)Pa{sup 227}, Th{sup 232}(p,3n)Pa{sup 230}, Th{sup 232}(d,7n)Pa{sup 227}, Th{sup 232}({alpha},p8n)Pa{sup 227}, Th{sup 232}({alpha},p5n)Pa{sup 230}, and U{sup 238}(p,{alpha}8n)Pa{sup 227}. The data are presented graphically and discussed individually for each of the reactions. Some rough excitation function data have also been determined for the reactions Th{sup 232}(d,4n)Pa{sup 230}, U{sup 238}(p,{alpha}5n)Pa{sup 230}, Th{sup 232}({alpha},7n)U{sup 229}, and Th{sup 232}({alpha},6n)U{sup 230}. The results are discussed in terms of compound nucleus formation, transparency effects, and other factors in order to arrive at a qualitative picture for the mechanism of high energy nuclear reactions with heavy nuclei.

An isotope of the element with atomic number 97 has been discovered as a product of the helium-ion bombardment of americium. This isotope decays with the emission of alpha-particles of maximum energy 6.72 Mev (30 percent) and it emits lower energy alpha-particles of energies 6.55 Mev (53 percent) and 6.20 Mev (17 percent). The half-life of this isotope is 4.6 hours and it decays primarily by electron capture with about 0.1 percent branching decay by alpha-particle emission. The mass number is probably 243 as indicated by chemical separation of the alpha-particle and electron-capture daughters. The name berkelium, symbol Bk, is proposed for element 97. The chemical separation of element 97 from the target material and other reaction products was made by combinations of precipitation and ion exchange adsorption methods making use of its anticipated (III) and (IV) oxidation states and its position as a member of the actinide transition series. The distinctive chemical properties made use of in its separation and the equally distinctive decay properties of the particular isotope constitute the principal evidence for the new element.

On June 14, 1950, an aluminum Kanne Chamber on the 108-B vacuum discharge line was placed in operation. The vacuum pump discharge line chamber has a very poor reputation for two reasons: 1. An apparent hysteresis effect which shows as a high reading after a slug of gas has passed through it, and 2. Failure to return to background current. Cause of the hysteresis effect may be the distribution of tritium in the vacuum pump discharge gas. The rate of gas flow through the Kanne chamber is approximately ten cubic feet per minute. In order to determine steps necessary to eliminate chamber contamination, the existence of contamination must first be definitely established by measuring chamber background with an uncontaminated air filling at intervals during routine use. Monitor chamber currents are now recorded on a multiple point recorder with a cycle time of approximately four minutes, a long wait which is annoying and may mask transient phenomena almost completely. The following steps are recommended to facilitate the necessary stack gas measurements: 1. Provide clean air flushing facilities for both Kanne chambers on the vacuum pump discharge line. 2. Replace existing recorder with continuous recording facilities for each point.

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This report describes contamination in the 100, 200, and 300 areas at Hanford in 1956.