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Yana Maneva

Parametrically unstable Alfven-cyclotron waves and wave-particle interactions in the solar corona and solar wind. Yana Maneva. Dynamic and hot X-ray corona:. Yohkoh SXT 3-5 Million K. Classical picture of the solar wind.

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Yana Maneva

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  1. Parametrically unstable Alfven-cyclotron waves and wave-particle interactions in the solar corona and solar wind YanaManeva

  2. Dynamic and hot X-ray corona: Yohkoh SXT 3-5 Million K Space Plasma Physics, Sozopol, 1-7 Sept. 2008

  3. Classical picture of the solar wind Large scale solar wind profile as a function of latitude during minimum (left) and maximum (right) solar cycle phases, adopted from Mc Comas et.al. 2003, American Geophysical Union Space Plasma Physics, Sozopol, 1-7 Sept. 2008

  4. Types of solar wind • Fast wind: a steady flow emanating from open magnetic field lines in CHs directly from the chromospheric magnetic network • Slow wind: unsteady flow coming from the tips and edges of temporarily open streamers or from opening loops and active regions • Transient wind: CMEs and MCs, prevailing during solar maximum Space Plasma Physics, Sozopol, 1-7 Sept. 2008

  5. Solar corona and solar wind – weakly collisional plasma laboratories Large electron mean free paths  other means for energy transfer: wave-particle interactions involved Space Plasma Physics, Sozopol, 1-7 Sept. 2008

  6. Common problems in the corona and solar wind: • Preferential heating: heavier ions hotter than protons, hotter than electrons • Temperature anisotropies: anisotropic electrons and protons, strong perpendicular heating of alphas and heavier ions (O VI) Space Plasma Physics, Sozopol, 1-7 Sept. 2008

  7. Temperature profiles in the corona and fast solar wind Corona Solar wind Cranmer et al., Ap.J., 2000 Space Plasma Physics, Sozopol, 1-7 Sept. 2008

  8. electrons Temperature anisotropies Marsch 2006 protons Space Plasma Physics, Sozopol, 1-7 Sept. 2008

  9. Different approaches to plasma physics: • single (test) particle approach • single-fluid MHD • multi-fluid MHD • KINETICS • HYBRID: numerical simulations Space Plasma Physics, Sozopol, 1-7 Sept. 2008

  10. Waves, instabilities and wave-particle interaction: • Waves in a cold isotropic plasma: Alfven, EMIC, Whistlers, fast mode • Free energy source for micro-instabilities: relative drift velocities, high kinetic temperatures, non-Maxwellian distributions, unstable Alfven waves • Collisionless wave-particle interaction:Landau and cyclotron resonances;quasi-linear diffusion Space Plasma Physics, Sozopol, 1-7 Sept. 2008

  11. Parametric instabilities: • Decay: pump wave “decays” into a backward lower sideband and forward sound wave • Beat:forward upper sideband and backward lower sideband ‘beat’ into a pump wave • Modulational:the pump results into forward upper or lower sideband and a sound Space Plasma Physics, Sozopol, 1-7 Sept. 2008

  12. Current work: numerical simulations • Hybrid code: fluid electrons, fully kinetic ions – J. Araneda • 1D, non-linear • homogeneous magnetized plasma • parallel propagation • treats parametric instabilities and non-linear wave-particle interactions Space Plasma Physics, Sozopol, 1-7 Sept. 2008

  13. Where do we look at? What happens here? Coronal hole SoHO, EIT, Fe XV Space Plasma Physics, Sozopol, 1-7 Sept. 2008

  14. What does the code do? • Solves collisionless kinetic (Vlasov) eq. for the ions self-consistently coupled to Maxwell equations and treats the electrons as a massless fluid • Starts with an equilibrium state of a non-linear circularly-polarized Alfven-ion-cyclotron wave with background ions and let it evolve Space Plasma Physics, Sozopol, 1-7 Sept. 2008

  15. Non-linear solution of the kinetic eq. – starting point for simulations Sonnerup’66 Vs – bulk velocity of the “s”-species Ωs – gyro-frequency for the “s”-species ωps – plasma frequency Exact nonlinear kinetic solution for hot isotropic homogeneous plasma Space Plasma Physics, Sozopol, 1-7 Sept. 2008

  16. Sonnerup’s solution for protons and α-particles: p-cyclotron mode Alfven- α-cyclotron fast mode Frequency and wave-number normalized to Ωp and VA Space Plasma Physics, Sozopol, 1-7 Sept. 2008

  17. Input parameters of the code: • Number densities: ni/ne • Anisotropies: • Plasma betas: • Drift velocities for the species: Us=0 (to understand the origin of the heating avoiding other free energy sources) • Normalization: VA, Ωp Space Plasma Physics, Sozopol, 1-7 Sept. 2008

  18. Growth of EM waves due to parametric instabilities βp=0.04, βα=0.02 Space Plasma Physics, Sozopol, 1-7 Sept. 2008

  19. Growth of ion-acoustic fluctuations Space Plasma Physics, Sozopol, 1-7 Sept. 2008

  20. EM and acoustic spectra Space Plasma Physics, Sozopol, 1-7 Sept. 2008

  21. Temperature anisotropies – perpendicular heating: 11/6/2019 Space Plasma Physics, Sozopol, 1-7 Sept. 2008 21

  22. Relative drift velocity Space Plasma Physics, Sozopol, 1-7 Sept. 2008

  23. Space Plasma Physics, Sozopol, 1-7 Sept. 2008

  24. Summary: • Wave-particle interactions – important for forming and re-shaping the distributions in the solar corona and SW • Non-linear Alfven-cyclotron waves – natural source of free energy for beam formations, as well as heavy particles’ acceleration and heating mechanisms • Parametric instabilities – natural cascading mechanism, shaping both acoustic and EM turbulent spectrum Space Plasma Physics, Sozopol, 1-7 Sept. 2008

  25. THANK YOU FOR YOUR ATTENTION! Space Plasma Physics, Sozopol, 1-7 Sept. 2008

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