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Fusion Science and Technology
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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.”
Masami Fujiwara, Nobuyoshi Ohyabu, Keisuke Matsuoka, Shoichi Okamura, Osamu Motojima, Tokuhiro Obiki, Fumimichi Sano, Katsumi Kondo, Masahiro Wakatani, Tohru Mizuuchi, Kiyoshi Hanatani, Yuji Nakamura, Kazunobu Nagasaki, Hiroyuki Okada, Sakae Besshou, Masahiko Nakasuga
Fusion Science and Technology | Volume 42 | Number 1 | July 2002 | Pages 32-49
Technical Paper | doi.org/10.13182/FST02-A211
Articles are hosted by Taylor and Francis Online.
Experimental results are summarized for major helical devices in Japan: Large Helical Device (LHD), Compact Helical System (CHS), and Heliotron J. The LHD and CHS have planar magnetic axes, while Heliotron J has a nonplanar magnetic axis.The LHD, the largest superconducting device in the world, has the following machine parameters: major radius R of 3.9 m, average minor radius a of 0.6 m, magnetic field on axis B of 3 T, multipolarity l of 2, toroidal period number m of 10, and auxiliary heating power P of ~14 MW. The LHD achieved the maximum stored energy Wp dia of > 1 MJ, the maximum value of the volume averaged beta <dia*gt; of >3.0% at B of 0.5 T, high confinement time E of 0.3 s at Te(0) of 1.1 keV and <ne> of 6.5 × 1019 m-3, and long pulse operations up to 120 s at high temperature.The CHS has the following machine parameters: R = 1 m, a = 0.2 m, l = 2, and m = 8. The parameters of neutral beam heated plasmas are in the range with <ne> of ~4 to 5 × 1019 m-3, Te(0) of 500 to 700 eV, and energy confinement time of several milliseconds. Progress has been made in studies of bifurcation phenomena of electric potential, neoclassical internal transport barriers, and plasma flows in the toroidal and poloidal directions.The most important achievement from recent CHS and LHD experiments is to realize the internal transport barriers on the basis of potential bifurcation.Heliotron J, which was converted from the Heliotron E (H-E) device, employs a helical magnetic axis by the use of l = 1 continuous helical coil and auxiliary coils such as poloidal and toroidal coils. The machine parameters are as follows: R = 1.2 m, a = 0.1 to 0.2 m, and B = 1 to 1.5 T. Initial results show the maximum stored energy Wp ~ 0.7 kJ and <> ~ 0.2%.The range of plasma parameters has been greatly expanded by the LHD, CHS, H-E, and Heliotron J experiments. The confinement data in helical devices are scaled empirically as ISS-95 (International Stellarator Scaling), and plasma performance is comparable with that in tokamaks.
