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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.”
Dennis L. Youchison, Michael G. Izenson, Chandu B. Baxi, John H. Rosenfeld
Fusion Science and Technology | Volume 29 | Number 4 | July 1996 | Pages 559-570
Technical Paper | Divertor Systems | doi.org/10.13182/FST29-559
Articles are hosted by Taylor and Francis Online.
High-heat-flux experiments on three types of helium-cooled divertor mock-ups were performed on the 30-kW electron beam test system and its associated helium flow loop at Sandia National Laboratories. A dispersion-strengthened copper alloy (DSCu) was used in the manufacture of all the mock-ups. The first heat exchanger was manufactured by Creare, Inc., and makes use of microfin technology and helium flow normal to the heated surface. This technology provides for enhanced heat transfer at relatively low flow rates and much reduced pumping requirements. The Creare sample was tested to a maximum absorbed heat flux of 5.8 MW/m2. The second helium-cooled divertor mock-up was designed and manufactured by General Atomics (GA). It consisted of millimetre-sized axial fins and flow channels machined in DSCu. This design used low pressure drops and high mass flow rates to achieve good heat removal. The GA specimen was tested to a maximum absorbed heat flux of 9 MW/m2 while maintaining a surface temperature below 400°C. This temperature was selected to be compatible with a 2-mm-thick beryllium tile at the plasma interface, where the maximum surface temperature must be below 700°C. A second experiment resulted in a maximum absorbed heat flux of 34 MW/m2 and surface temperatures near 533°C. The third specimen was a DSCu, axial flow, helium-cooled divertor mock-up filled with a porous metal wick designed and manufactured by Thermacore, Inc. The internal porous metal wick effectively increases the available heat transfer area. Low mass flow and high pressure drop operation at 4.0 MPa were characteristic of this divertor module. It survived a maximum absorbed heat flux of 16 MW/m2 and reached a surface temperature of 740°C. Thermacore also manufactured a follow-on, dual channel porous metal-type heat exchanger. This “unit cell” divertor module was an ïmprovement over the previous design because it utilized short flow lengths to minimize pressure drops and pumping requirements. It survived a maximum absorbed heat flux of 14 MW/m2 and reached a maximum surface temperature of 690°C.