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
Materials Science & Technology
The objectives of MSTD are: promote the advancement of materials science in Nuclear Science Technology; support the multidisciplines which constitute it; encourage research by providing a forum for the presentation, exchange, and documentation of relevant information; promote the interaction and communication among its members; and recognize and reward its members for significant contributions to the field of materials science in nuclear technology.
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
First astatine-labeled compound shipped in the U.S.
The Department of Energy’s National Isotope Development Center (NIDC) on March 31 announced the successful long-distance shipment in the United States of a biologically active compound labeled with the medical radioisotope astatine-211 (At-211). Because previous shipments have included only the “bare” isotope, the NIDC has described the development as “unleashing medical innovation.”
Charles E. Cohn, Robert J. Johnson and Robert N. Macdonald
Nuclear Science and Engineering | Volume 26 | Number 2 | October 1966 | Pages 198-206
Technical Paper | doi.org/10.13182/NSE66-A28162
Articles are hosted by Taylor and Francis Online.
A method has been developed by which statics techniques can be used to calculate source transfer functions in the multigroup, multidimensional approximation. With the flux resolved into steady and fluctuating components, the time-dependent neutron balance equations are satisfied by the fluctuating part alone. Assuming that the external source and the flux response are sinusoidal, the original time-dependent equations transform into a set of complex equations dependent on space and frequency but independent of time. Separating the equations into real and imaginary parts yields coupled, inhomogeneous differential equations (two for each group). These can be solved by well-known statics techniques for the real and imaginary components φR and φI of the complex amplitudes of the fluxes, in turn yielding the gain and phase shift for each frequency of interest. This method was applied to the NORA reactor for which the space-dependent transfer function had been determined experimentally. The two-group telegrapher's equations were programmed for one-dimensional cylindrical geometry and the difference equations solved by direct matrix inversion and also by interative techniques. Results of the calculations closely reproduce the reported experimental results for gain and phase shift.