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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.”
Yuelei Wu, Huasi Hu, Tiankui Zhang, Zhenghong Li, Yuanping Zhan, Zhenyu Jiang, Jun Chu
Fusion Science and Technology | Volume 57 | Number 3 | April 2010 | Pages 292-297
Technical Paper | doi.org/10.13182/FST10-A9472
Articles are hosted by Taylor and Francis Online.
The relationship and differences between pinhole imaging and penumbral imaging are explained and discussed in detail. A Monte Carlo (MC) model for a practical fusion neutron penumbral imaging system, which is expected to be used as one of the diagnostics of the nuclear facilities in China, was established. The source consists of many assumed discrete elements whose sizes equal the minimum resolution of the imaging system and that are identical to the point source in general concept. The point spread functions (PSFs) of two assumed discrete elements, located in the center and at the edge of a 200-m field of view (FOV) in the neutron source face, were obtained for two cases, respectively: imaging in geometrical near-optics and the more real case of an MC numerical experiment. A series of PSFs of points in the diameter of FOV were obtained, and the PSF spatial shift invariance tolerances were tested within [approximately]20 m accuracy. Using mathematical analysis convolution and MC numerical experiments, "penumbral images" of a neutron source, which consists of just four discrete elements in 20-m space, were obtained. Employing the same program, the two penumbral images were reconstructed, and the obtained original source images were basically the same. This allows the nature of encoding and decoding by the neutron penumbral imaging aperture prototype, which was designed by our work group, to be visualized and realized.