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The Radiation Protection and Shielding Division is developing and promoting radiation protection and shielding aspects of nuclear science and technology — including interaction of nuclear radiation with materials and biological systems, instruments and techniques for the measurement of nuclear radiation fields, and radiation shield design and evaluation.
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ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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February 2025
Latest News
WEST claims latest plasma confinement record
The French magnetic confinement fusion tokamak known as WEST maintained a plasma in February for more than 22 minutes—1,337 seconds, to be precise—and “smashed” the previous record plasma duration for a tokamak with a 25 percent improvement, according to the CEA, which operates the machine. The previous 1,006-second record was set by China’s EAST just a few weeks prior. Records are made to be broken, but this rapid progress illustrates a collective, global increase in plasma confinement expertise, aided by tungsten in key components.
R. England, J. P. Hennart, J. G. Martin, L. Melendez L., S. M. Waller
Nuclear Science and Engineering | Volume 64 | Number 1 | September 1977 | Pages 132-140
Technical Paper | doi.org/10.13182/NSE77-A27084
Articles are hosted by Taylor and Francis Online.
Fluid equations for a low-beta plasma, where the ratio of the kinetic to the magnetic pressure is small, constitute a system of parabolic partial-differential equations. Depending on the particular assumptions made, this may be a system of three equations for density, electron temperature, and ion temperature, or a single density equation, or a system of four equations where the current density or magnetic field also has to be determined. Such equations were previously solved by one-dimensional models, imposing some additional form of symmetry. In two dimensions, strongly anisotropic diffusion coefficients cause a spurious numerical loss of plasma. This problem was tackled in various geometries for the single density equation, and adequate mass conservation methods were developed. The two principal components of the diffusion were separated and, by a method of fractional steps, were treated by distinct methods. The diffusion parallel to the magnetic field was treated as a one-dimensional problem by two different techniques, (a) using a nonstandard Galerkin finite element, and (b) resulting from an averaging process across a flux tube. Meanwhile, the perpendicular diffusion, when treated by a Galerkin finite element method, gives rise to very wide band matrices, a problem that can be resolved advantageously by using the alternating direction implicit method.