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ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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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.”
Scott D. Ramsey, Roy A. Axford, Gregory J. Hutchens
Nuclear Science and Engineering | Volume 166 | Number 1 | September 2010 | Pages 73-81
Technical Note | doi.org/10.13182/NSE09-63TN
Articles are hosted by Taylor and Francis Online.
Stochastic point kinetics neglecting delayed neutrons has been subject to rigorous analysis in the years since its introduction. Many approximate solutions appearing within this context are based upon the “quadratic approximation,” where fission multiplicity is truncated at two. In this technical note we review the quadratic approximation within the context of a stochastic, space-independent, one-energy-group model neglecting delayed neutrons and its generalization to higher-order approximations in transient and stationary systems. This generalization results in the probability of a zero neutron population for a source-free system being governed by transcendental and polynomial algebraic equations in the transient and infinite time limit cases, respectively. For 239Pu, we solve the transcendental equation over a wider range of prompt multiplication factors and times than has been previously accomplished. We also reproduce and generalize associated solutions of the polynomial algebraic equation. In both cases, solutions are computed for successive generalizations of the quadratic approximation to higher-order maximum fission multiplicity.