scholarly journals Hybrid simulation of ion cyclotron resonance in the solar wind: Evolution of velocity distribution functions

2005 ◽  
Vol 110 (A10) ◽  
Author(s):  
Xing Li ◽  
Shadia R. Habbal
Keyword(s):  
Solar Wind ◽  
Velocity Distribution ◽  
Cyclotron Resonance ◽  
Hybrid Simulation ◽  
Distribution Functions ◽  
Ion Cyclotron Resonance ◽  
Ion Cyclotron ◽  
Velocity Distribution Functions

scholarly journals Combined electron firehose and electromagnetic ion cyclotron instabilities: quasilinear approach

2020 ◽  
Vol 499 (1) ◽  
pp. 659-667
Author(s):  
Z Ali ◽  
M Sarfraz ◽  
P H Yoon
Keyword(s):  
Solar Wind ◽  
Dynamical Evolution ◽  
Solar Wind Plasma ◽  
Distribution Functions ◽  
Temperature Anisotropy ◽  
Spatial And Temporal Scales ◽  
Proton Temperature ◽  
Ion Cyclotron ◽  
Velocity Distribution Functions ◽  
High Beta

ABSTRACT Various plasma waves and instabilities are abundantly present in the solar wind plasma, as evidenced by spacecraft observations. Among these, propagating modes and instabilities driven by temperature anisotropies are known to play a significant role in the solar wind dynamics. In situ measurements reveal that the threshold conditions for these instabilities adequately explain the solar wind conditions at large heliocentric distances. This paper pays attention to the combined effects of electron firehose instability driven by excessive parallel electron temperature anisotropy (T⊥e < T∥e) at high beta conditions, and electromagnetic ion cyclotron instability driven by excessive perpendicular proton temperature anisotropy (T⊥i > T∥i). By employing quasilinear kinetic theory based upon the assumption of bi-Maxwellian velocity distribution functions for protons and electrons, the dynamical evolution of the combined instabilities and their mutual interactions mediated by the particles is explored in depth. It is found that while in some cases, the two unstable modes are excited and saturated at distinct spatial and temporal scales, in other cases, the two unstable modes are intermingled such that a straightforward interpretation is not so easy. This shows that when the dynamics of protons and electrons are mutually coupled and when multiple unstable modes are excited in the system, the dynamical consequences can be quite complex.

On the multifractality of plasma turbulence in the solar wind

2019 ◽  
Vol 15 (S354) ◽  
pp. 371-374
Author(s):  
Sebastián Echeverría ◽  
Pablo S. Moya ◽  
Denisse Pastén
Keyword(s):  
Solar Wind ◽  
Velocity Distribution ◽  
Distribution Functions ◽  
Fluctuation Analysis ◽  
Magnetic Fluctuations ◽  
Multifractal Detrended Fluctuation Analysis ◽  
Particle In Cell ◽  
Velocity Distribution Functions ◽  
Detrended Fluctuation

AbstractIn this work we have analyzed turbulent plasma in the kinetic scale by the characterization of magnetic fluctuations time series. Considering numerical Particle-In-Cell (PIC) simulations we apply a method known as MultiFractal Detrended Fluctuation Analysis (MFDFA) to study the fluctuations of solar-wind-like plasmas in thermodynamic equilibrium (represented by Maxwellian velocity distribution functions), and out of equilibrium plasma represented by Tsallis velocity distribution functions, characterized by the kappa (κ) parameter, to stablish relations between the fractality of magnetic fluctuation and the kappa parameter.

Direct Measurement of Ion Cyclotron Resonance Between Wave Fields and Protons in Space Plasmas

2021 ◽  
Author(s):  
Qiaowen Luo ◽  
Xingyu Zhu ◽  
Jiansen He ◽  
Jun Cui ◽  
Hairong Lai ◽  
...  
Keyword(s):  
Kinetic Theory ◽  
Electric Field ◽  
Velocity Distribution ◽  
Wave Field ◽  
Cyclotron Resonance ◽  
Space Plasmas ◽  
Ion Cyclotron Resonance ◽  
Wave Fields ◽  
Ion Cyclotron Waves ◽  
Ion Cyclotron

<p>Ion cyclotron resonance is one of the fundamental energy conversion processes through wave field-particle interaction in collisionless plasma. However, the key evidence for cyclotron resonance (i.e., the coherence between wave field and ion phase space density pertaining to the ion cyclotron resonance and responsible for the dissipation of ion cyclotron waves (ICWs)) has yet to be directly observed. Based on the high-quality measurements of space plasma by the Magnetospheric Multiscale (MMS) satellites, we observe that both the wave electromagnetic field vectors and the disturbed ion velocity distribution rotate around the background magnetic field. Moreover, we find that the gyrophase angle difference between the fluctuations in the ion velocity distribution functions and the wave electric field vectors are always in the range of (0, 90) degrees, clearly suggesting the ongoing energy conversion from wave fields to particles. By invoking plasma kinetic theory, we find that the field-particle correlation for the dissipative ion cyclotron waves in the theoretical model matches well with our observations. Furthermore, all the wave electric field vectors (Ewave), the ion current (Ji) and the energy transfer rate (Ji ·Ewave) exhibit quasi-periodic oscillations, and the frequency of Ji ·Ewave is about twice the frequency of Ewave and Ji, consistent with plasma kinetic theory. Therefore, our combined analysis of MMS observations and kinetic theory provides direct, thorough, and comprehensive evidence for ICW dissipation in space plasmas.</p>

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