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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.”
E. Starr, H. Honeck, J. DeVilliers†
Nuclear Science and Engineering | Volume 18 | Number 2 | February 1964 | Pages 230-235
Technical Paper | doi.org/10.13182/NSE64-A18322
Articles are hosted by Taylor and Francis Online.
This describes an experimental technique to determine the average velocity of the thermal-neutron spectrum as a function of time in a pulsed-neutron experiment. The measurement of the average velocity as a function of time is used to determine two parameters: the time necessary to establish an asymptotic spectrum, and the average velocity of the asymptotic spectrum. The variation in the asymptotic average velocity with material buckling is described by a “spectral-shift coefficient” which is related to the diffusion-cooling coefficient. It was found necessary to wait 2 milliseconds for the establishment of an equilibrium spectrum in graphite, and 0.6 milliseconds in heavy water, and that these values are insensitive to the geometric buckling. Values of the spectral-shift coefficient are given and compared with theoretical estimates.
