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This division promotes the development and timely introduction of fusion energy as a sustainable energy source with favorable economic, environmental, and safety attributes. The division cooperates with other organizations on common issues of multidisciplinary fusion science and technology, conducts professional meetings, and disseminates technical information in support of these goals. Members focus on the assessment and resolution of critical developmental issues for practical fusion energy applications.
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Smarter waste strategies: Helping deliver on the promise of advanced nuclear
At COP28, held in Dubai in 2023, a clear consensus emerged: Nuclear energy must be a cornerstone of the global clean energy transition. With electricity demand projected to soar as we decarbonize not just power but also industry, transport, and heat, the case for new nuclear is compelling. More than 20 countries committed to tripling global nuclear capacity by 2050. In the United States alone, the Department of Energy forecasts that the country’s current nuclear capacity could more than triple, adding 200 GW of new nuclear to the existing 95 GW by mid-century.
Erik L. Vold, Anil K. Prinja, Farrokh Najmabadi, Robert W. Conn
Fusion Science and Technology | Volume 22 | Number 2 | September 1992 | Pages 208-226
Technical Paper | Plasma Engineering | doi.org/10.13182/FST92-A30104
Articles are hosted by Taylor and Francis Online.
A one-group diffusion approximation to neutral transport in a plasma is incorporated in a two-dimensional (θ-r) computational code, EPIC, coupling transport and recycling of the plasma-neutral fluids in a consistent finite discretization scheme. Boundary conditions accommodate particle recycling at the edge-core plasma interface. Neutral particle reflection from the pumping duct characterizes a given pumping system. Marginal validity of the diffusion approximation motivates extensive comparisons of the results with Monte Carlo (DEGAS) transport calculations. In prescribed and in self-consistently computed plasma solutions, the neutral diffusion results are comparable with the Monte Carlo results for radial and poloidal profiles of atomic neutral density over a wide range of limiter and divertor edge plasmas. Steady-state density and temperature contours for the Axially Symmetric Divertor Experiment (ASDEX) diverted tokamak are consistent with previous computations using fixed boundary conditions at the separatrix, but show reduced (20%) recycling attributed to the more realistic neutral atom transport by charge-exchange scattering in the diffusion model. Time-dependent plasma solutions with flux boundary conditions across the separatrix are more consistent with experimental data than results with fixed value boundary conditions at the separatrix. The flux across the separatrix is dominated by recycled particles from the edge plasma. A conclusion is that while the one-group diffusion treatment oversimplifies the physics of neutral transport, it is computationally efficient and adequate in accuracy and therefore well suited for edge plasma and for plasma-neutral recycling studies.
