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The division was organized to promote the advancement of knowledge of the use of particle accelerator technologies for nuclear and other applications. It focuses on production of neutrons and other particles, utilization of these particles for scientific or industrial purposes, such as the production or destruction of radionuclides significant to energy, medicine, defense or other endeavors, as well as imaging and diagnostics.
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ANS Student Conference 2025
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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.”
H. L. McMurry
Nuclear Science and Engineering | Volume 15 | Number 4 | April 1963 | Pages 429-437
Technical Paper | doi.org/10.13182/NSE63-A26460
Articles are hosted by Taylor and Francis Online.
As an approach to developing methods for calculating differential scattering cross sections of materials for neutrons with energy below 1 ev five approximations to the exact formalism of Zemach and Glauber have been applied to treat the scattering by gases composed of semirigid molecules. This paper outlines the theory for the methods which are the following (1) A quite rigorous method valid when the neutron energy and kBT are both much less than the characteristic vibrational energies of the molecules. (2) A method which treats vibrations harmonically rotations classically, and neglects rotation-vibration coupling. Within these limitations the method is valid at all neutron energies. (3) A method like (2) except that averages over orientation are approximated by the Kneger-Nelkin method of introducing average values of functions of the Eulerian angles wherever they appear. (4) A method which treats vibrations with characteristic energies much less than the neutron energy by a short collision time approximation. (5) A method which treats such low energy vibrations classically. Method (5) has the feature that when all normal modes are treated classically the equation for the differential scattering cross section reduces to that for scattering by unbound particles. If some, but not all, vibrations are treated classically and averages over orientation are approximated as in method (3) the effective mass for a scattering atom attached to the molecule is intermediate between the mass of the atom and the Sachs-Teller mass which applies when all vibrations are treated exactly by quantum mechanics. Method (5) has the advantage of being easily adapted to treating simple models for liquids and amorphous solids. These methods are evaluated in the accompanying paper.
