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Isotopes & Radiation
Members are devoted to applying nuclear science and engineering technologies involving isotopes, radiation applications, and associated equipment in scientific research, development, and industrial processes. Their interests lie primarily in education, industrial uses, biology, medicine, and health physics. Division committees include Analytical Applications of Isotopes and Radiation, Biology and Medicine, Radiation Applications, Radiation Sources and Detection, and Thermal Power Sources.
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ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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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.”
Praneel P. Gulabrao, Kevin T. Clarno
Nuclear Science and Engineering | Volume 195 | Number 2 | February 2021 | Pages 161-172
Technical Paper | doi.org/10.1080/00295639.2020.1794455
Articles are hosted by Taylor and Francis Online.
Photon buildup is a function of energy, medium, and geometry and therefore must be specifically calculated for the case of interest. The Martian atmosphere, mostly comprising carbon dioxide, is becoming more relevant to radiation researchers and therefore warrants the study of this gas mixture’s buildup properties for ionizing photon flux resulting from the secondary effects of galactic cosmic rays and solar flares. Specifically, this work uses the MCNP6 code to develop energy absorption buildup factors in finite slab models for energies ranging from 40 keV to 15 MeV with Martian regolith as the backscattering medium. The Martian carbon dioxide cycle is accounted for by determining maximum and minimum mean densities as a function of orbital position. An isotropic point source model for the atmosphere is also developed using the geometric progression fitting function. Buildup is bounded to a factor of approximately 23 at 100 keV for normally incident photons at the top of the atmosphere. For conservatism, the design problem neglects coherent scattering but assumes bremsstrahlung effects and uses Klein-Nishina free-electron cross sections for Compton scattering.