A Fresh Look at Waves in Ion-Electron Plasmas
Exploiting the general dispersion relation describing all waves in an ideal ion-electron fluid, we revisit established treatments on wave families in a cold ion-electron plasma. These contain the magnetohydrodynamic Alfvén and fast waves at low frequencies, long wavelengths, but are enriched by shor...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2019-03-01
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| Series: | Frontiers in Astronomy and Space Sciences |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/article/10.3389/fspas.2019.00011/full |
| _version_ | 1818411611760623616 |
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| author | Rony Keppens Rony Keppens Hans Goedbloed |
| author_facet | Rony Keppens Rony Keppens Hans Goedbloed |
| author_sort | Rony Keppens |
| collection | DOAJ |
| description | Exploiting the general dispersion relation describing all waves in an ideal ion-electron fluid, we revisit established treatments on wave families in a cold ion-electron plasma. These contain the magnetohydrodynamic Alfvén and fast waves at low frequencies, long wavelengths, but are enriched by short wavelength resonance behaviors, electrostatic and electromagnetic mode types, and cut-off frequencies distinguishing propagating from evanescent waves. Our theoretical treatment exploits purely polynomial expressions, which for the cold ion-electron case only depend on 2 parameters: the ratio of masses over charges μ and the ratio E of the electron gyro frequency to the combined ion-electron plasma frequency. We provide a complete description of all waves, which stresses the intricate variation of all five branches of eigenfrequencies ω(k, ϑ) depending on wavenumber k and angle ϑ between wavevector and magnetic field B. Corresponding 5-mode phase and group diagrams provide insight on wave transformations and energy transport. Special cases, like the high frequency modes in magneto-ionic theory following from Appleton-Hartree dispersion relations, are naturally recovered and critically discussed. Faraday rotation for electromagnetic waves is extended to all propagation angles ϑ. The discussion covers all cold ion-electron plasma waves, up into the relativistic regime. |
| first_indexed | 2024-12-14T10:34:10Z |
| format | Article |
| id | doaj.art-6d744764bef84eeba5872dd319257102 |
| institution | Directory Open Access Journal |
| issn | 2296-987X |
| language | English |
| last_indexed | 2024-12-14T10:34:10Z |
| publishDate | 2019-03-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Astronomy and Space Sciences |
| spelling | doaj.art-6d744764bef84eeba5872dd3192571022022-12-21T23:06:00ZengFrontiers Media S.A.Frontiers in Astronomy and Space Sciences2296-987X2019-03-01610.3389/fspas.2019.00011447705A Fresh Look at Waves in Ion-Electron PlasmasRony Keppens0Rony Keppens1Hans Goedbloed2Centre for mathematical Plasma Astrophysics, KU Leuven, Leuven, BelgiumSchool of Physics and Astronomy, Yunnan University, Kunming, ChinaDIFFER, TU/e Science Park, Eindhoven, NetherlandsExploiting the general dispersion relation describing all waves in an ideal ion-electron fluid, we revisit established treatments on wave families in a cold ion-electron plasma. These contain the magnetohydrodynamic Alfvén and fast waves at low frequencies, long wavelengths, but are enriched by short wavelength resonance behaviors, electrostatic and electromagnetic mode types, and cut-off frequencies distinguishing propagating from evanescent waves. Our theoretical treatment exploits purely polynomial expressions, which for the cold ion-electron case only depend on 2 parameters: the ratio of masses over charges μ and the ratio E of the electron gyro frequency to the combined ion-electron plasma frequency. We provide a complete description of all waves, which stresses the intricate variation of all five branches of eigenfrequencies ω(k, ϑ) depending on wavenumber k and angle ϑ between wavevector and magnetic field B. Corresponding 5-mode phase and group diagrams provide insight on wave transformations and energy transport. Special cases, like the high frequency modes in magneto-ionic theory following from Appleton-Hartree dispersion relations, are naturally recovered and critically discussed. Faraday rotation for electromagnetic waves is extended to all propagation angles ϑ. The discussion covers all cold ion-electron plasma waves, up into the relativistic regime.https://www.frontiersin.org/article/10.3389/fspas.2019.00011/fullwavescold plasmas2-fluid theorymagnetohydrodynamicelectromagnetic wave theory |
| spellingShingle | Rony Keppens Rony Keppens Hans Goedbloed A Fresh Look at Waves in Ion-Electron Plasmas Frontiers in Astronomy and Space Sciences waves cold plasmas 2-fluid theory magnetohydrodynamic electromagnetic wave theory |
| title | A Fresh Look at Waves in Ion-Electron Plasmas |
| title_full | A Fresh Look at Waves in Ion-Electron Plasmas |
| title_fullStr | A Fresh Look at Waves in Ion-Electron Plasmas |
| title_full_unstemmed | A Fresh Look at Waves in Ion-Electron Plasmas |
| title_short | A Fresh Look at Waves in Ion-Electron Plasmas |
| title_sort | fresh look at waves in ion electron plasmas |
| topic | waves cold plasmas 2-fluid theory magnetohydrodynamic electromagnetic wave theory |
| url | https://www.frontiersin.org/article/10.3389/fspas.2019.00011/full |
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