Generation and Evolution of Fluctuations in a Non-equilibrium Solar Wind Plasma

• Applicant: Professor Dr. Reinhard Schlickeiser
• Subject Area: Astrophysics and Astronomy
• Term: from 2016 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 315239725

• Final Report Year: 2021

Final Report Abstract

Natural plasmas from heliosphere, e.g., the expanding solar wind and planetary magnetospheres, are plasmas out of thermal equilibrium. This is unequivocally proved by the in-situ observations, which reveal not only non-Maxwellian velocity distributions of plasma particles, e.g., kinetic anisotropies and suprathermal, Kappa-distributed populations, but also a multi-scale spectra of wave turbulence and fluctuations. The project has proved a strong inter-connection between these two components, by advanced investigations of the kinetic (low-scale) instability mechanisms. On the one hand, anisotropic distributions are important sources of wave instabilities and low-scale fluctuations. It was shown that temperature anisotropy instabilities are markedly enhanced by the suprathermal populations. On the other hand, the low-scale plasma waves can interact resonantly with electrons and protons in the solar wind, triggering their departures from thermal equilibrium and explaining an enhanced presence of suprathermal halo populations with increasing the heliocentric distance.

Publications

• Electromagnetic cyclotron instabilities in bi-Kappa distributed plasmas: A quasilinear approach, Phys. Plasmas 24 (2017) 042110
  Lazar, M., Yoon, P.H. and Eliasson, B.
  (See online at https://doi.org/10.1063/1.4979903)
• Electromagnetic electron cyclotron instability in the solar wind, J. Geophys. Res. 123 (2018) 6
  Lazar, M., Yoon, P.H., López, R.A., and Moya, P.S.
  (See online at https://doi.org/10.1002/2017JA024759)
• Modified κ-distribution of solar wind electrons and steady-state Langmuir turbulence, Astrophys. J. 868 (2018), 131
  Yoon, P.H., Lazar, M., Scherer, K., Fichtner, H., Schlickeiser, R.
  (See online at https://doi.org/10.3847/1538-4357/aaeb94)
• Temperature anisotropy instabilities stimulated by the interplay of the core and halo electrons in space plasmas, Phys. Plasmas 25 (2018) 022902
  Lazar, M., Shaaban, S.M., Fichtner, H., and Poedts, S.
  (See online at https://doi.org/10.1063/1.5016261)
• Firehose instabilities triggered by the solar wind suprathermal electrons, MNRAS 483 (2019) 5642
  Shaaban, S.M., Lazar, M., López, R.A., Fichtner, H., Poedts, S.
  (See online at https://doi.org/10.1093/mnras/sty3377)
• Particle-in-cell simulations of firehose instability driven by bi-Kappa electrons, Astrophys. J. Lett. 873 (2019) L20
  López, R.A., Lazar, M., Shaaban, S.M., et al.
  (See online at https://doi.org/10.3847/2041-8213/ab0c95)
• The interplay of the solar wind core and suprathermal electrons: A quasilinear approach for firehose instability, Astrophys. J. 871 (2019) 237
  Shaaban, S.M., Lazar, M., Yoon, P.H., Poedts, S.
  (See online at https://doi.org/10.3847/1538-4357/aaf72d)
• Whistler instability stimulated by the suprathermal electrons present in space plasmas, Astrophys. Space Sci. 364 (2019) id. 171
  Lazar, M., López, R.A., Shaaban, S.M., Poedts, S., Fichtner, H.
  (See online at https://doi.org/10.1007/s10509-019-3661-6)
• Electromagnetic ion cyclotron instability stimulated by the suprathermal ions in space plasmas: A quasi-linear approach, Phys. Plasmas 28 (2021) id.022103
  Shaaban, S.M., Lazar, M., Schlickeiser, R.
  (See online at https://doi.org/10.1063/5.0035798)