ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Division Spotlight
Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
Meeting Spotlight
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
Standards Program
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!
Latest Magazine Issues
Apr 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
May 2025
Nuclear Technology
April 2025
Fusion Science and Technology
Latest News
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.”
B.J. Peterson, J.N. Talmadge, D.T. Anderson, F.S.B. Anderson, P.G. Matthews, J.L. Shohet
Fusion Science and Technology | Volume 27 | Number 3 | April 1995 | Pages 215-218
Helical Systems | doi.org/10.13182/FST95-A11947072
Articles are hosted by Taylor and Francis Online.
Mach probe measurements of bias-induced ion flows were made in the Interchangeable Module Stellarator (IMS) as a function of neutral pressure and viscosity (which increases with minor radius) and compared to a fluid theory model. Using a probe model for an unmagnetized plasma, the poloidal flow speed measured with a Mach probe agrees with that calculated from momentum balance to within 15%. The dependencies of the measured ion flow magnitudes and decay rates on neutral pressure and viscosity as predicted by the theory are qualitatively observed in the experimental measurements, clearly demonstrating the effects of both ion-neutral collisions and viscosity in the damping of the bias-induced flows. However, the measured flow direction is nearly poloidal, while the theory predicts a predominantly Pfirsch-Schlüter-like toroidal flow. Also, the two-dimensional variation at a constant toroidal angle of the parallel electron current was measured in an unbiased plasma. The measured profiles demonstrate the dependence of the current on both the radial pressure gradient and the cosine of the poloidal angle, as predicted by theory.