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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.”
Owen N. Jarvis, Edward W. Clipsham, Malcolm A. Hone, Brian J. Laundy, Mario Pillon, Massimo Rapisarda, Guy J. Sadler, Pieter van Belle, Karl A. Verschuur
Fusion Science and Technology | Volume 20 | Number 3 | November 1991 | Pages 265-284
Technical Paper | Experiment Device | doi.org/10.13182/FST91-A29668
Articles are hosted by Taylor and Francis Online.
The time dependence of the 2.5-MeV neutron emission from the Joint European Torus (JET) is reliably measured using fission chambers. The absolute calibration of these chambers is required to an accuracy of 10% or better for a range of intensities that may cover six or more decades. At JET, this calibration is now achieved by use of activation techniques, the most convenient of which involves fissionable materials (thorium and uranium) and delayed neutron counting. Because delayed neutron counting is unfamiliar in the fusion community, particular care is taken to obtain confirmation of the results based on this method by comparison with measurements made using the conventional activation procedure (involving indium, nickel, and zinc as target materials). As the activation measurements can be influenced appreciably by the weak emission of 14-MeV neutrons, this contribution is measured separately using high threshold energy activation reactions (in copper and silicon). Neutron transport calculations are employed to relate the measured local fluences of both 2,5- and 14-MeV neutrons to the total yields from the plasma. Absolute calibration accuracies of 6 and 8% are claimed for 2,5- and 14-MeV neutron yields, respectively; the accuracy of the 14-MeV to 2,5-MeV yield ratios is 6%.