scholarly journals Kinetics of parametric instabilities of Alfvén waves: Evolution of ion distribution functions

2010 ◽  
Vol 115 (A9) ◽  
pp. n/a-n/a ◽  
Author(s):  
Lorenzo Matteini ◽  
Simone Landi ◽  
Marco Velli ◽  
Petr Hellinger
Keyword(s):  
Alfven Waves ◽  
Distribution Functions ◽  
Alfvén Waves ◽  
Ion Distribution ◽  
Parametric Instabilities ◽  
Kinetics Of

Parametric instabilities of Alfvén waves in a dusty plasma

2003 ◽  
Vol 10 (8) ◽  
pp. 3160-3167 ◽  
Author(s):  
M. P. Hertzberg ◽  
N. F. Cramer ◽  
S. V. Vladimirov
Keyword(s):  
Dusty Plasma ◽  
Alfven Waves ◽  
Alfvén Waves ◽  
Parametric Instabilities

Parametric instabilities of finite-amplitude, circularly polarized Alfvén waves in an anisotropic plasma

1993 ◽  
Vol 49 (1) ◽  
pp. 29-39 ◽  
Author(s):  
Hiromitsu Hamabata
Keyword(s):  
Finite Amplitude ◽  
Alfven Waves ◽  
Mhd Equations ◽  
Alfvén Waves ◽  
Linear Perturbation ◽  
Plasma Parameters ◽  
Circularly Polarized ◽  
Pressure Anisotropy ◽  
Parametric Instabilities ◽  
Fifth Order

A class of parametric instabilities of finite-amplitude, circularly polarized Alfvén waves in a plasma with pressure anisotropy is studied by application of the CGL equations. A linear perturbation analysis is used to find the dispersion relation governing the instabilities, which is a fifth-order polynomial and is solved numerically. A large-amplitude, circularly polarized wave is unstable with respect to decay into three waves: one sound-like wave and two side-band Alfvén-like waves. It is found that, in addition to the decay instability, two new instabilities that are absent in the framework of the MHD equations can occur, depending on the plasma parameters.

scholarly journals Solar wind and kinetic heliophysics

2018 ◽  
Vol 36 (6) ◽  
pp. 1607-1630 ◽  
Author(s):  
Eckart Marsch
Keyword(s):  
Solar Wind ◽  
Interplanetary Space ◽  
Coronal Holes ◽  
Heavy Ion ◽  
Alfven Waves ◽  
Distribution Functions ◽  
Slow Solar Wind ◽  
Alfvén Waves ◽  
The Sun ◽  
Collisionless Dissipation

Abstract. This paper reviews recent aspects of solar wind physics and elucidates the role Alfvén waves play in solar wind acceleration and turbulence, which prevail in the low corona and inner heliosphere. Our understanding of the solar wind has made considerable progress based on remote sensing, in situ measurements, kinetic simulation and fluid modeling. Further insights are expected from such missions as the Parker Solar Probe and Solar Orbiter. The sources of the solar wind have been identified in the chromospheric network, transition region and corona of the Sun. Alfvén waves excited by reconnection in the network contribute to the driving of turbulence and plasma flows in funnels and coronal holes. The dynamic solar magnetic field causes solar wind variations over the solar cycle. Fast and slow solar wind streams, as well as transient coronal mass ejections, are generated by the Sun's magnetic activity. Magnetohydrodynamic turbulence originates at the Sun and evolves into interplanetary space. The major Alfvén waves and minor magnetosonic waves, with an admixture of pressure-balanced structures at various scales, constitute heliophysical turbulence. Its spectra evolve radially and develop anisotropies. Numerical simulations of turbulence spectra have reproduced key observational features. Collisionless dissipation of fluctuations remains a subject of intense research. Detailed measurements of particle velocity distributions have revealed non-Maxwellian electrons, strongly anisotropic protons and heavy ion beams. Besides macroscopic forces in the heliosphere, local wave–particle interactions shape the distribution functions. They can be described by the Boltzmann–Vlasov equation including collisions and waves. Kinetic simulations permit us to better understand the combined evolution of particles and waves in the heliosphere.

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