Hostname: page-component-5d84bcc8dc-z9l2z Total loading time: 0 Render date: 2026-09-08T02:23:50.256Z Has data issue: false hasContentIssue false
  • English
  • Français

The effects of density inhomogeneities on the radio wave emission in electron beam plasmas

Part of: Focus on Plasma Astrophysics

Published online by Cambridge University Press:  08 March 2021

Xin Yao Open the ORCID record for Xin Yao [Opens in a new window] ,
Patricio A. Muñoz Open the ORCID record for Patricio A. Muñoz [Opens in a new window] ,
Jörg Büchner Open the ORCID record for Jörg Büchner [Opens in a new window] ,
Xiaowei Zhou Open the ORCID record for Xiaowei Zhou [Opens in a new window]  and
Siming Liu Open the ORCID record for Siming Liu [Opens in a new window]
Xin Yao*
Affiliation:
Max Planck Institute for Solar System Research, 37077 Göttingen, Germany Centre for Astronomy and Astrophysics, Technical University of Berlin, 10623 Berlin, Germany
Patricio A. Muñoz
Affiliation:
Centre for Astronomy and Astrophysics, Technical University of Berlin, 10623 Berlin, Germany
Jörg Büchner
Affiliation:
Max Planck Institute for Solar System Research, 37077 Göttingen, Germany Centre for Astronomy and Astrophysics, Technical University of Berlin, 10623 Berlin, Germany
Xiaowei Zhou
Affiliation:
Max Planck Institute for Solar System Research, 37077 Göttingen, Germany Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, 210034 Nanjing, PR China
Siming Liu
Affiliation:
Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, 210034 Nanjing, PR China
*
†Email address for correspondence: xin.yao@campus.tu-berlin.de
Get access Rights & Permissions [Opens in a new window]

Abstract

Type III radio bursts are radio emissions associated with solar flares. They are considered to be caused by electron beams travelling from the solar corona to the solar wind. Magnetic reconnection is a possible accelerator of electron beams in the course of solar flares since it causes unstable distribution functions and density inhomogeneities (cavities). The properties of radio emission by electron beams in an inhomogeneous environment are still poorly understood. We capture the nonlinear kinetic plasma processes of the generation of beam-related radio emissions in inhomogeneous plasmas by utilizing fully kinetic particle-in-cell code numerical simulations. Our model takes into account initial electron velocity distribution functions (EVDFs) as they are supposed to be created by magnetic reconnection. We focus our analysis on low-density regions with strong magnetic fields. The assumed EVDFs allow two distinct mechanisms of radio wave emissions: plasma emission due to wave–wave interactions and so-called electron cyclotron maser emission (ECME) due to direct wave–particle interactions. We investigate the effects of density inhomogeneities on the conversion of free energy from the electron beams into the energy of electrostatic and electromagnetic waves via plasma emission and ECME, as well as the frequency shift of electron resonances caused by perpendicular gradients in the beam EVDFs. Our most important finding is that the number of harmonics of Langmuir waves increases due to the presence of density inhomogeneities. The additional harmonics of Langmuir waves are generated by a coalescence of beam-generated Langmuir waves and their harmonics.

Keywords

astrophysical plasmasplasma wavesplasma simulation

Information

Type
Research Article
Information
Journal of Plasma Physics , Volume 87 , Issue 2 , April 2021 , 905870203
Check for updates
Copyright
Copyright © The Author(s), 2021. Published by Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable

References

Alvarez, H. & Haddock, F. T. 1973 Solar wind density model from km-wave type III bursts. Sol. Phys. 29 (1), 197–209.CrossRefGoogle Scholar
Annenkov, V. V., Timofeev, I. V. & Volchok, E. P. 2019 Highly efficient electromagnetic emission during 100 keV electron beam relaxation in a thin magnetized plasma. Phys. Plasmas 26 (6), 063104.CrossRefGoogle Scholar
Aschwanden, M. 2006 Physics of the Solar Corona: An Introduction with Problems and Solutions. Springer Science & Business Media.Google Scholar
Benáček, J. & Karlický, M. 2017 Double plasma resonance instability as a source of solar zebra emission. Astron. Astrophys. 611, A60.CrossRefGoogle Scholar
Bessho, N., Chen, L.-J., Shuster, J. R. & Wang, S. 2014 Electron distribution functions in the electron diffusion region of magnetic reconnection: physics behind the fine structures. Geophys. Res. Lett. 41 (24), 8688–8695.CrossRefGoogle Scholar
Bingham, R. & Cairns, R. A. 2000 Generation of auroral kilometric radiation by electron horseshoe distributions. Phys. Plasmas 7 (7), 3089–3092.CrossRefGoogle Scholar
Bingham, R., Kellett, B. J., Cairns, R. A., Tonge, J. & Mendonca, J. T. 2003 Cyclotron maser radiation from astrophysical shocks. Astrophys. J. 595 (1), 279.CrossRefGoogle Scholar
Büchner, J. & Kuska, J. P. 1996 On the formation of cup-like ion beam distributions in the plasma sheet boundary layer. Earth Planet. Space 48 (5–6), 781–797.Google Scholar
Cairns, I. H. & Willes, A. J. 2005 Angle-averaged efficiencies for linear mode conversion between Langmuir waves and radiation in an unmagnetized plasma. Phys. Plasmas 12 (5), 052315.CrossRefGoogle Scholar
Comişel, H., Verscharen, D., Narita, Y. & Motschmann, U. 2013 Spectral evolution of two-dimensional kinetic plasma turbulence in the wavenumber-frequency domain. Phys. Plasmas 20 (9), 090701.CrossRefGoogle Scholar
Drake, J. F., Swisdak, M., Cattell, C., Shay, M. A., Rogers, B. N. & Zeiler, A. 2003 Formation of electron holes and particle energization during magnetic reconnection. Science (80-.) 299 (5608), 873–877.CrossRefGoogle ScholarPubMed
Ellis, G. R. A. 1962 Cyclotron radiation from Jupiter. Austral. J. Phys. 15 (3), 344–353.CrossRefGoogle Scholar
Fleishman, G. D. & Mel'nikov, V. F. 1998 Millisecond solar radio spikes. Phys. Uspekhi 41 (12), 1157.CrossRefGoogle Scholar
Gaelzer, R., Ziebell, L. F. & Yoon, P. H. 2002 Generation of harmonic langmuir mode by beam-plasma instability. Phys. Plasmas 9 (1), 96.CrossRefGoogle Scholar
Ganse, U., Kilian, P., Vainio, R. & Spanier, F. 2012 Emission of type II radio bursts – single-beam versus two-beam scenario. Sol. Phys. 280 (2), 551–560.CrossRefGoogle Scholar
Ginzburg, V. L. & Zhelezniakov, V. V. 1958 On the possible mechanisms of sporadic solar radio emission (radiation in an isotropic plasma). Astron. Zh. 35, 694.Google Scholar
Henri, P., Sgattoni, A., Briand, C., Amiranoff, F. & Riconda, C. 2019 Electromagnetic simulations of solar radio emissions. J. Geophys. Res. 124 (3), 1475–1490.CrossRefGoogle Scholar
Kilian, P., Burkart, T. & Spanier, F. 2012 The influence of the mass ratio on particle acceleration by the filamentation instability. In High Performance Computing in Science and Engineering (ed. Wolfgang E. Nagel, Dietmar H. Kröner & Michael M. Resch), pp. 5–13. Springer.CrossRefGoogle Scholar
Kim, E. H., Cairns, I. H. & Robinson, P. A. 2007 Extraordinary-mode radiation produced by linear-mode conversion of Langmuir waves. Phys. Rev. Lett. 99 (1), 015003.CrossRefGoogle ScholarPubMed
Klassen, A., Karlicky, M. & Mann, G. 2003 Superluminal apparent velocities of relativistic electron beams in the solar corona. Astron. Astrophys. 410 (1), 307–314.CrossRefGoogle Scholar
Krafft, C. & Volokitin, A. S. 2020 Electromagnetic radiation from upper-hybrid wave turbulence in inhomogeneous solar plasmas. Plasma Phys. Control. Fusion 62, 024007.CrossRefGoogle Scholar
Krafft, C., Volokitin, A. S. & Krasnoselskikh, V. V. 2015 Langmuir wave decay in inhomogeneous solar wind plasmas: simulation results. Astrophys. J. 809 (2), 176.CrossRefGoogle Scholar
Krasnoselskikh, V., Voshchepynets, A. & Maksimovic, M. 2019 On the efficiency of the linear-mode conversion for generation of solar type III radio bursts. Astrophys. J. 879 (1), 51.CrossRefGoogle Scholar
Lee, K. H., Omura, Y. & Lee, L. C. 2011 A 2D simulation study of Langmuir, whistler, and cyclotron maser instabilities induced by an electron ring-beam distribution. Phys. Plasmas 18, 092110.CrossRefGoogle Scholar
Li, B., Cairns, I. H. & Robinson, P. A. 2009 Simulations of coronal type III solar radio bursts: 3. Effects of beam and coronal parameters. J. Geophys. Res. 114 (2), A02104.Google Scholar
Malaspina, D. M., Cairns, I. H. & Ergun, R. E. 2012 Antenna radiation near the local plasma frequency by Langmuir wave eigenmodes. Astrophys. J. 755, 45.CrossRefGoogle Scholar
Melrose, D. B. 1970 a On the theory of type II and type III solar radio bursts. I. The impossibility of nonthermal emission due to combination scattering off thermal fluctuations. Austral. J. Phys. 23 (5), 871–884.CrossRefGoogle Scholar
Melrose, D. B. 1970 b On the theory of type II and type III solar radio bursts. II. Alternative model. Austral. J. Phys. 23 (5), 885–904.CrossRefGoogle Scholar
Melrose, D. B. 1986 Instabilities in Space and Laboratory Plasmas. Cambridge University Press.CrossRefGoogle Scholar
Melrose, D. B. 2017 Coherent emission mechanisms in astrophysical plasmas. Rev. Mod. Plasma Phys. 1, 5.CrossRefGoogle Scholar
Melrose, D. B., Dulk, G. A. & Smerd, S. F. 1978 The polarization of second harmonic plasma emission. Astron. Astrophys. 66, 315–324.Google Scholar
Melrose, D. B. & Wheatland, M. S. 2016 Is cyclotron maser emission in solar flares driven by a horseshoe distribution? Sol. Phys. 291 (12), 3637–3658.CrossRefGoogle Scholar
Morosan, D. E., Zucca, P., Bloomfield, D. S. & Gallagher, P. T. 2016 Conditions for electron-cyclotron maser emission in the solar corona. Astron. Astrophys. 589, L8.CrossRefGoogle Scholar
Muñoz, P. A. & Büchner, J. 2016 Non-Maxwellian electron distribution functions due to self-generated turbulence in collisionless guide-field reconnection. Phys. Plasmas 23 (10), 102103.CrossRefGoogle Scholar
Muñoz, P. A. & Büchner, J. 2018 Kinetic turbulence in fast three-dimensional collisionless guide-field magnetic reconnection. Phys. Rev. E 98 (4), 043205.CrossRefGoogle Scholar
Pechhacker, R. & Tsiklauri, D. 2012 The effect of electron beam pitch angle and density gradient on solar type III radio bursts. Phys. Plasmas 19, 112903.CrossRefGoogle Scholar
Poquerusse, M. 1994 Relativistic type III solar radio bursts. Astron. Astrophys. 286, 611–625.Google Scholar
Pritchett, P. L. 1984 Relativistic dispersion, the cyclotron maser instability, and auroral kilometric radiation. J. Geophys. Res. 89 (A10), 8957–8970.CrossRefGoogle Scholar
Pritchett, P. L. & Coroniti, F. V. 2004 Three-dimensional collisionless magnetic reconnection in the presence of a guide field. J. Geophys. Res. 109, A01220.Google Scholar
Regnier, S. 2015 A new approach to the maser emission in the solar corona. Astron. Astrophys. 581, A9.CrossRefGoogle Scholar
Reid, H. A. S. & Kontar, E. P. 2018 Spatial expansion and speeds of type III electron beam sources in the solar corona. Astrophys. J. 867 (2), 158.CrossRefGoogle Scholar
Reid, H. A. S. & Ratcliffe, H. 2014 A review of solar type III radio bursts. Res. Astron. Astrophys. 14 (7), 773.CrossRefGoogle Scholar
Reiner, M. J. & MacDowall, R. J. 2019 New evidence for third harmonic electromagnetic radiation in interplanetary type III solar radio bursts. Sol. Phys. 294, 91.CrossRefGoogle Scholar
Reiner, M. J., Stone, R. G. & Fainberg, J. 1992 Detection of fundamental and harmonic type III radio emission and the associated Langmuir waves at the source region. Astrophys. J. 394, 340–350.CrossRefGoogle Scholar
Rhee, T., Ryu, C. M., Woo, M., Kaang, H. H., Yi, S. & Yoon, P. H. 2009 Multiple harmonic plasma emission. Astrophys. J. 694 (1), 618–625.CrossRefGoogle Scholar
Ricci, P., Brackbill, J. U., Daughton, W. & Lapenta, G. 2004 Collisionless magnetic reconnection in the presence of a guide field. Phys. Plasmas 11 (8), 4102–4114.CrossRefGoogle Scholar
Sakai, J. I., Kitamoto, T. & Saito, S. 2005 Simulation of solar type III radio bursts from a magnetic reconnection region. Astrophys. J. Lett. 622 (2), L157.CrossRefGoogle Scholar
Schmitz, H. & Tsiklauri, D. 2013 The effect of initial conditions on the electromagnetic radiation generation in type III solar radio bursts. Phys. Plasmas 20, 062903.CrossRefGoogle Scholar
Shuster, J. R., Chen, L. J., Daughton, W. S., Lee, L. C., Lee, K. H., Bessho, N., Torbert, R. B., Li, G. & Argall, M. R. 2014 Highly structured electron anisotropy in collisionless reconnection exhausts. Geophys. Res. Lett. 41 (15), 5389–5395.CrossRefGoogle Scholar
Smerd, S. F. 1976 Fundamental and harmonic radiation in solar type III bursts. Sol. Phys. 46 (2), 493–498.CrossRefGoogle Scholar
Stix, T. H. 1992 Waves in Plasmas. Springer Science & Business Media.Google Scholar
Takakura, T. & Yousef, S. 1974 The third harmonic of type III solar radio bursts. Sol. Phys. 36 (2), 451–458.CrossRefGoogle Scholar
Thurgood, J. O. & Tsiklauri, D. 2015 Self-consistent particle-in-cell simulations of fundamental and harmonic plasma radio emission mechanisms. Astron. Astrophys. 584, A83.CrossRefGoogle Scholar
Thurgood, J. O. & Tsiklauri, D. 2016 Particle-in-cell simulations of the relaxation of electron beams in inhomogeneous solar wind plasmas. J. Plasma Phys. 82, 905820604.CrossRefGoogle Scholar
Tokar, R. L., Aldrich, C. H., Forslund, D. W. & Quest, K. B. 1986 Nonadiabatic electron heating at high-Mach-number perpendicular shocks. Phys. Rev. Lett. 56 (10), 1059.CrossRefGoogle ScholarPubMed
Treumann, R. A. 2006 The electron-cyclotron maser for astrophysical application. Astron. Astrophys. Rev. 13 (4), 229–315.CrossRefGoogle Scholar
Treumann, R. A. & Baumjohann, W. 2013 Collisionless magnetic reconnection in space plasmas. Front. Phys. 1 (M), 1–34.CrossRefGoogle Scholar
Treumann, R. A. & Baumjohann, W. 2017 Electron cyclotron maser instability (ECMI) in strong magnetic guide field reconnection. Ann. Geophys. 35 (4), 999–1013.CrossRefGoogle Scholar
Tsiklauri, D. 2011 An alternative to the plasma emission model: particle-in-cell, self-consistent electromagnetic wave emission simulations of solar type III radio bursts. Phys. Plasmas 18, 052903.CrossRefGoogle Scholar
Twiss, R. Q. 1958 Radiation transfer and the possibility of negative absorption in radio astronomy. Austral. J. Phys. 11 (4), 564–579.CrossRefGoogle Scholar
Vandas, M. & Hellinger, P. 2015 Linear dispersion properties of ring velocity distribution functions. Phys. Plasmas 22 (6), 62107.CrossRefGoogle Scholar
Voitcu, G. & Echim, M. 2018 Crescent-shaped electron velocity distribution functions formed at the edges of plasma jets interacting with a tangential discontinuity. Ann. Geophys. 36 (6), 1521–1535.CrossRefGoogle Scholar
Voitcu, G. & Echim, M. M. 2012 Ring-shaped velocity distribution functions in energy-dispersed structures formed at the boundaries of a proton stream injected into a transverse magnetic field: test-kinetic results. Phys. Plasmas 19 (2), 22903.CrossRefGoogle Scholar
Volokitin, A. S. & Krafft, C. 2018 Electromagnetic wave emissions from a turbulent plasma with density fluctuations. Astrophys. J. 868 (2), 104.CrossRefGoogle Scholar
Wilczek, M. & Narita, Y. 2012 Wave-number-frequency spectrum for turbulence from a random sweeping hypothesis with mean flow. Phys. Rev. E 86 (6), 066308.CrossRefGoogle ScholarPubMed
Wild, J. P., Sheridan, K. V. & Neylan, A. A. 1959 An investigation of the speed of the solar disturbances responsible for type III radio bursts. Austral. J. Phys. 12 (4), 369–398.CrossRefGoogle Scholar
Wu, C. S. & Lee, L. C. 1979 A theory of the terrestrial kilometric radiation. Astrophys. J. 230, 621–626.CrossRefGoogle Scholar
Wu, C. S., Wang, C. B., Wu, D. J. & Lee, K. H. 2012 Resonant wave-particle interactions modified by intrinsic Alfvénic turbulence. Phys. Plasmas 19 (8), 82902.CrossRefGoogle Scholar
Wu, C. S., Wang, C. B., Yoon, P. H., Zheng, H. N. & Wang, S. 2002 Generation of type III solar radio bursts in the low corona by direct amplification. Astrophys. J. 575 (2), 1094.CrossRefGoogle Scholar
Wu, D. J., Chen, L., Zhao, G. Q. & Tang, J. F. 2014 A novel mechanism for electron-cyclotron maser. Astron. Astrophys. 566, A138.CrossRefGoogle Scholar
Yi, S., Yoon, P. H. & Ryu, C.-M. 2007 Multiple harmonic plasma emission. Phys. Plasmas 14 (1), 13301.CrossRefGoogle Scholar
Yoon, P. H. 2000 Generalized weak turbulence theory. Phys. Plasmas 7 (12), 4858–4871.CrossRefGoogle Scholar
Yoon, P. H., Gaelzer, R., Umeda, T., Omura, Y. & Matsumoto, H. 2003 Harmonic Langmuir waves. I. Nonlinear dispersion relation. Phys. Plasmas 10 (2), 364–372.CrossRefGoogle Scholar
Yoon, P. H., Yi, S. & Ryu, C. M. 2005 Harmonics of electromagnetic and electrostatic plasma waves. Phys. Plasmas 12 (5), 052305.CrossRefGoogle Scholar
Zhou, X., Büchner, J., Bárta, M., Gan, W. & Liu, S. 2015 Electron acceleration by cascading reconnection in the solar corona. I. Magnetic gradient and curvature drift effects. Astrophys. J. 815 (1), 6.CrossRefGoogle Scholar
Zhou, X., Muñoz, P. A., Büchner, J. & Liu, S. 2020 Wave excitation by energetic ring-distributed electron beams in the solar corona. Astrophys. J. 891 (1), 92.CrossRefGoogle Scholar