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August 24–27, 2026
Dallas, TX|Hilton Anatole
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Fusion Science and Technology
Latest News
In transition: Commercializing fusion power
Commercial fusion power is closer than ever. There are now around 30 U.S. fusion companies, several of which claim to be on track to connect to the grid as early as the 2030s.
Tokamak and laser inertial confinement approaches benefit from decades of research at facilities such as the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory and ITER, with alternative concepts including stellarator, magnetic mirror, and Z-pinch confinement also making notable progress as private and government funding for fusion increases.
L. A. Hageman, J. B. Yasinsky
Nuclear Science and Engineering | Volume 38 | Number 1 | October 1969 | Pages 8-32
Technical Paper | doi.org/10.13182/NSE38-8
Articles are hosted by Taylor and Francis Online.
Alternating-direction implicit (ADI) time-differencing approximations are developed for the two-dimensional neutron group-diffusion equations. These methods are analyzed for accuracy and stability relative to the implicit-difference approach used in the TWIGL program. It is shown that for model problems (bare homogenous reactors with constant material properties) the ADI method is as accurate as the TWIGL method and much faster computationally. However, several numerical comparisons show that the ADI approach is asymptotically unstable for non-model problems unless extremely small time-steps are used. Such comparisons show the ADI methods (considered in this paper) to be inferior to the TWIGL method for realistic reactor-dynamic problems. A variant on the ADI scheme (ADI-B2) is developed and for a class of delayed supercritical problems shown to be potentially superior to all methods considered.
