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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.”
George N. Salaita, Andrew Robeson
Nuclear Science and Engineering | Volume 46 | Number 2 | November 1971 | Pages 214-222
Technical Paper | doi.org/10.13182/NSE71-A22355
Articles are hosted by Taylor and Francis Online.
The diffusion parameters for mixtures of 0, 20, 50, 80, and 100% D2O in H2O have been measured by the pulsed-neutron method at temperatures near the freezing point and in ice at -20°C. A 250-keV Cockcroft-Walton accelerator was used to produce neutron bursts in cylindrical samples by the 2K(d,n)3Re reaction. The waiting time method was used for establishment of the asymptotic spectrum in each sample. The infinite medium decay constants for D2O were evaluated from known density and nuclear cross-section data; those for H2O, H2O ice, and (H2O + D2O) mixtures were determined by a three parameter least-squares fit of the experimental data to the equation λ = λ0 + DoB2 - CB4. An iterative procedure was used to make the value of the extrapolated distance compatible with the diffusion coefficient D0 derived from the least-squares analysis. The results are compared with those of similar measurements by other workers for H2O and D2O at various temperatures. The effect of the liquid-solid phase transition on the diffusion coefficient and diffusion cooling coefficient in H2O and D2O is discussed. The expression D0 = 1 / αi/D0,i, where αi and D0,i are the fractional volume and diffusion coefficient of the i’th component of the mixture, respectively, gave lower values than the experimental results for the mixtures.