Paraxial beams in fluctuating fusion plasmas: Diffusive limit and beyond
A paraxial expansion of the (ensemble-averaged) Wigner function in the relevant wave kinetic equation for electron cyclotron waves in fluctuating plasmas allows the derivation of phase-space equations similar to the equations for the Gaussian beam parameters in the paraxial WKB method [G.V. Pereverz...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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EDP Sciences
2023-01-01
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| Series: | EPJ Web of Conferences |
| Online Access: | https://www.epj-conferences.org/articles/epjconf/pdf/2023/03/epjconf_ec212023_01003.pdf |
| _version_ | 1797894078021500928 |
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| author | Weber Hannes Maj Omar Poli Emanuele |
| author_facet | Weber Hannes Maj Omar Poli Emanuele |
| author_sort | Weber Hannes |
| collection | DOAJ |
| description | A paraxial expansion of the (ensemble-averaged) Wigner function in the relevant wave kinetic equation for electron cyclotron waves in fluctuating plasmas allows the derivation of phase-space equations similar to the equations for the Gaussian beam parameters in the paraxial WKB method [G.V. Pereverzev, Phys. Plasmas 5, 3529 (1998)]. This is relatively straightforward when the scattering of the wave field by density fluctuations can be described by a diffusion operator in refractive-index space. The general case is rather more complicated, yet we could find a heuristic construction of a paraxial Wigner function. Here we use a simple model, which has an analytical solution, to test both the theoretical validity of the diffusion approximation and the heuristic paraxial approach beyond the diffusion approximation. |
| first_indexed | 2024-04-10T07:03:07Z |
| format | Article |
| id | doaj.art-b8843e1e7e3e49f494218021128909e3 |
| institution | Directory Open Access Journal |
| issn | 2100-014X |
| language | English |
| last_indexed | 2024-04-10T07:03:07Z |
| publishDate | 2023-01-01 |
| publisher | EDP Sciences |
| record_format | Article |
| series | EPJ Web of Conferences |
| spelling | doaj.art-b8843e1e7e3e49f494218021128909e32023-02-27T15:17:49ZengEDP SciencesEPJ Web of Conferences2100-014X2023-01-012770100310.1051/epjconf/202327701003epjconf_ec212023_01003Paraxial beams in fluctuating fusion plasmas: Diffusive limit and beyondWeber Hannes0Maj Omar1Poli Emanuele2Max-Planck-Institut für PlasmaphysikMax-Planck-Institut für PlasmaphysikMax-Planck-Institut für PlasmaphysikA paraxial expansion of the (ensemble-averaged) Wigner function in the relevant wave kinetic equation for electron cyclotron waves in fluctuating plasmas allows the derivation of phase-space equations similar to the equations for the Gaussian beam parameters in the paraxial WKB method [G.V. Pereverzev, Phys. Plasmas 5, 3529 (1998)]. This is relatively straightforward when the scattering of the wave field by density fluctuations can be described by a diffusion operator in refractive-index space. The general case is rather more complicated, yet we could find a heuristic construction of a paraxial Wigner function. Here we use a simple model, which has an analytical solution, to test both the theoretical validity of the diffusion approximation and the heuristic paraxial approach beyond the diffusion approximation.https://www.epj-conferences.org/articles/epjconf/pdf/2023/03/epjconf_ec212023_01003.pdf |
| spellingShingle | Weber Hannes Maj Omar Poli Emanuele Paraxial beams in fluctuating fusion plasmas: Diffusive limit and beyond EPJ Web of Conferences |
| title | Paraxial beams in fluctuating fusion plasmas: Diffusive limit and beyond |
| title_full | Paraxial beams in fluctuating fusion plasmas: Diffusive limit and beyond |
| title_fullStr | Paraxial beams in fluctuating fusion plasmas: Diffusive limit and beyond |
| title_full_unstemmed | Paraxial beams in fluctuating fusion plasmas: Diffusive limit and beyond |
| title_short | Paraxial beams in fluctuating fusion plasmas: Diffusive limit and beyond |
| title_sort | paraxial beams in fluctuating fusion plasmas diffusive limit and beyond |
| url | https://www.epj-conferences.org/articles/epjconf/pdf/2023/03/epjconf_ec212023_01003.pdf |
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