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Reactor Physics
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ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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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.”
J. Seol, K. C. Shaing
Fusion Science and Technology | Volume 78 | Number 2 | February 2022 | Pages 111-118
Technical Paper | doi.org/10.1080/15361055.2021.1960090
Articles are hosted by Taylor and Francis Online.
Since the magnetic field strength is not constant on the magnetic flux surface, the flow also varies so that the density compression occurs along the poloidal direction. Since the inhomogeneous flow causes the density compression in the poloidal direction, the parallel flow is also perturbed. In this study, we investigate the effects of the parallel flow perturbation on the geodesic acoustic mode (GAM) when it is described by the kinetic approach. Using the continuity equation, it is shown that the flow perturbation in the geodesic curvature direction is balanced by the lowest-order term of the density perturbation in , and the flow perturbation in the parallel direction is balanced by the higher-order terms of the density perturbation. Since the density perturbation includes both the perpendicular and parallel flow perturbation contributions, the GAM frequency obtained by the kinetic approach has the parallel flow perturbation contribution, which is 1/ term in the GAM frequency equation. The low frequency branch of the dispersion relation is also discussed to demonstrate the connection between the GAM theory and neoclassical theory for the first time. It is shown that the flow perturbation in the geodesic curvature direction is balanced mostly by the parallel flow perturbation. It means that the flow in the flux surface is divergence free approximately as in the usual transport ordering. Thus, the poloidal flow goes to the neoclassical flow when the low frequency branch is taken.
