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Explanation of Experimentally Observed Phenomena in Hot Tokamak Plasmas from the Nonequilibrium Thermodynamics Position

In studying the hot plasma behavior in tokamak devices, the classical approach for collisional processes is traditionally used. This approach leaves unexplained a number of phenomena observed in experiments related to plasma energy confinement. Further, it is well known that tokamak plasma is always...

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Detalles Bibliográficos
Autores principales: Razumova, Ksenia A., Andreev, Valerii F., Kasyanova, Nadezhda V., Lysenko, Sergey E.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7516485/
https://www.ncbi.nlm.nih.gov/pubmed/33285828
http://dx.doi.org/10.3390/e22010053
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author Razumova, Ksenia A.
Andreev, Valerii F.
Kasyanova, Nadezhda V.
Lysenko, Sergey E.
author_facet Razumova, Ksenia A.
Andreev, Valerii F.
Kasyanova, Nadezhda V.
Lysenko, Sergey E.
author_sort Razumova, Ksenia A.
collection PubMed
description In studying the hot plasma behavior in tokamak devices, the classical approach for collisional processes is traditionally used. This approach leaves unexplained a number of phenomena observed in experiments related to plasma energy confinement. Further, it is well known that tokamak plasma is always turbulent and self-organized. In the present paper, we show that the nonequilibrium thermodynamics approach allows us to explain many observed dependences and paradoxes; for example, puffing of impurities results in confinement improvement if zones of plasma cooling by impurities and additional plasma heating are not overlapped. The analysis of the experimental results shows the important role of radiation losses at the plasma edge in the processes determining its total energy confinement. It is shown that the generally accepted dependence of energy confinement on plasma density is not quite adequate because it is a consequence of dependence on radiation losses. The phenomenon of the appearance of internal transport barriers and magnetic islands can also be explained by plasma self-organization. The obtained results may be taken into account when calculating the operation of a future tokamak reactor.
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spelling pubmed-75164852020-11-09 Explanation of Experimentally Observed Phenomena in Hot Tokamak Plasmas from the Nonequilibrium Thermodynamics Position Razumova, Ksenia A. Andreev, Valerii F. Kasyanova, Nadezhda V. Lysenko, Sergey E. Entropy (Basel) Article In studying the hot plasma behavior in tokamak devices, the classical approach for collisional processes is traditionally used. This approach leaves unexplained a number of phenomena observed in experiments related to plasma energy confinement. Further, it is well known that tokamak plasma is always turbulent and self-organized. In the present paper, we show that the nonequilibrium thermodynamics approach allows us to explain many observed dependences and paradoxes; for example, puffing of impurities results in confinement improvement if zones of plasma cooling by impurities and additional plasma heating are not overlapped. The analysis of the experimental results shows the important role of radiation losses at the plasma edge in the processes determining its total energy confinement. It is shown that the generally accepted dependence of energy confinement on plasma density is not quite adequate because it is a consequence of dependence on radiation losses. The phenomenon of the appearance of internal transport barriers and magnetic islands can also be explained by plasma self-organization. The obtained results may be taken into account when calculating the operation of a future tokamak reactor. MDPI 2019-12-30 /pmc/articles/PMC7516485/ /pubmed/33285828 http://dx.doi.org/10.3390/e22010053 Text en © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Razumova, Ksenia A.
Andreev, Valerii F.
Kasyanova, Nadezhda V.
Lysenko, Sergey E.
Explanation of Experimentally Observed Phenomena in Hot Tokamak Plasmas from the Nonequilibrium Thermodynamics Position
title Explanation of Experimentally Observed Phenomena in Hot Tokamak Plasmas from the Nonequilibrium Thermodynamics Position
title_full Explanation of Experimentally Observed Phenomena in Hot Tokamak Plasmas from the Nonequilibrium Thermodynamics Position
title_fullStr Explanation of Experimentally Observed Phenomena in Hot Tokamak Plasmas from the Nonequilibrium Thermodynamics Position
title_full_unstemmed Explanation of Experimentally Observed Phenomena in Hot Tokamak Plasmas from the Nonequilibrium Thermodynamics Position
title_short Explanation of Experimentally Observed Phenomena in Hot Tokamak Plasmas from the Nonequilibrium Thermodynamics Position
title_sort explanation of experimentally observed phenomena in hot tokamak plasmas from the nonequilibrium thermodynamics position
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7516485/
https://www.ncbi.nlm.nih.gov/pubmed/33285828
http://dx.doi.org/10.3390/e22010053
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