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General Kenneth Nichols and the Manhattan Project
Nichols
The Oak Ridger has published the latest in a series of articles about General Kenneth D. Nichols, the Manhattan Project, and the 1954 Atomic Energy Act. The series has been produced by Nichols’ grandniece Barbara Rogers Scollin and Oak Ridge (Tenn.) city historian David Ray Smith. Gen. Nichols (1907–2000) was the district engineer for the Manhattan Engineer District during the Manhattan Project.
As Smith and Scollin explain, Nichols “had supervision of the research and development connected with, and the design, construction, and operation of, all plants required to produce plutonium-239 and uranium-235, including the construction of the towns of Oak Ridge, Tennessee, and Richland, Washington. The responsibility of his position was massive as he oversaw a workforce of both military and civilian personnel of approximately 125,000; his Oak Ridge office became the center of the wartime atomic energy’s activities.”
J. Richard Smith, John J. King
Fusion Science and Technology | Volume 19 | Number 3 | May 1991 | Pages 1925-1930
Neutronic | Proceedings of the Ninth Topical Meeting on the Technology of Fusion Energy (Oak Brook, Illinois, October 7-11, 1990) | doi.org/10.13182/FST91-A29623
Articles are hosted by Taylor and Francis Online.
Neutron multiplication occurs in beryllium because of the high (n, 2n) cross section. On the basis of calculations made using microscopic nuclear data, multiplication in a beryllium blanket should improve the efficiency of a tritium breeder. Previous experiments have indicated that the net multiplication is too low for beryllium to be an effective neutron multiplier. It seemed appropriate to make a further study of the multiplication of 14-MeV neutrons in bulk beryllium, utilizing the superior isotropy and flat energy response of the manganese bath. In the manganese bath method a 14-MeV neutron source is placed at the center of a large tank containing an aqueous solution of MnSO4. With a beryllium sample surrounding the neutron source in the sample chamber, the neutrons first multiply in beryllium and produce in the manganese bath an activity proportional to the source rate times the multiplication factor. The ratio of the “sample-in” and the “open beam” activities is the raw value of the multiplication. Several systematic corrections must then be applied to deduce the true multiplication in beryllium. Uncorrected values of the multiplication have been obtained for beryllium samples of four thicknesses. For beryllium thicknesses of 4.6, 12.0, 15.6, and 19.9 cm the multiplication values are 1.399, 1.928, 2.072, and 2.126, respectively. These values are affected by several systematic effects characteristic of the manganese bath. The values of these systematic corrections are established by a combination of calculation and experimental parameterization. The detailed calculations use the Monte Carlo program MCNP. The experimental values are in good agreement with those calculated from microscopic cross sections.