Quasilinear dynamics of ion cyclotron instability in an anisotropic plasma

1970 ◽  
Vol 4 (1) ◽  
pp. 175-186 ◽  
Author(s):  
J. Preinhaelter ◽  
J. Václavík
Keyword(s):  
Distribution Function ◽  
Magnetoactive Plasma ◽  
Ion Distribution ◽  
Magnetostatic Field ◽  
Ion Cyclotron Waves ◽  
Anisotropic Temperature ◽  
Electrons And Ions ◽  
Ion Cyclotron ◽  
Cold Electrons ◽  
Maximum Increment

It is shown that in a dense magnetoactive plasma c/cA ≫ 1 with cold electrons and ions with an anisotropic temperature the ion cyclotron waves propagating along the magnetostatic field are excited with a maximum increment. The dynamics of the quasilinear stage of this instability is investigated. It turns out that, at any moment, the ion distribution function is of the form of a step with the steep front. The speed of the front in the velocity space and the characteristic time of the relaxation process are found. It is ascertained that the distribution function arising in the course of the relaxation is stable with respect to the ion cyclotron waves propagating obliquely to the magnetostatic field.

Minority-ion distribution function of a plasma under fundamental and second-harmonic ion-cyclotron heating

1995 ◽  
Vol 53 (1) ◽  
pp. 3-23 ◽  
Author(s):  
B. Weyssow
Keyword(s):  
Distribution Function ◽  
Kinetic Equation ◽  
Second Harmonic ◽  
Hermite Polynomials ◽  
Collision Term ◽  
Algebraic Equations ◽  
Ion Temperature ◽  
Ion Distribution ◽  
Ion Cyclotron ◽  
Analytical Result

The distribution function of the minority ions during ion-cyclotron heating is calculated from a kinetic equation composed of a Landau collision term and a surface-averaged quasi-linear heating term. The kinetic equation is solved by a moment method in which the minority-ion distribution function is expanded in irreducible tensorial Hermite polynomials. The coefficients of the expansion are shown to be solutions of a system of coupled algebraic equations, and the effective minority-ion temperature is deduced from a compatibility constraint. The latter equation is in general too complicated to be solved analytically. The distribution function obtained here is therefore a semi-analytical result.

scholarly journals Enhanced ion acoustic lines due to strong ion cyclotron wave fields

2008 ◽  
Vol 26 (8) ◽  
pp. 2081-2095 ◽  
Author(s):  
H. Bahcivan ◽  
R. Cosgrove
Keyword(s):  
Distribution Function ◽  
Electric Fields ◽  
Near Field ◽  
Electron Distribution Function ◽  
Ion Distribution ◽  
Incoherent Scatter Radars ◽  
Ion Acoustic ◽  
Ion Cyclotron ◽  
Observational Fact ◽  
Step Mechanism

Abstract. The Fast Auroral Snapshot Explorer (FAST) satellite detected intense and coherent 5–20 m electric field structures in the high-latitude topside auroral ionosphere between the altitudes of 350 km and 650 km. These electric fields appear to belong to electrostatic ion cyclotron (EIC) waves in terms of their frequency and wavelengths. Numerical simulations of the response of an electron plasma to the parallel components of these fields show that the waves are likely to excite a wave-driven parallel ion acoustic (IA) instability, through the creation of a highly non-Maxwellian electron distribution function, which when combined with the (assumed) Maxwellian ion distribution function provides inverse Landau damping. Because the counter-streaming threshold for excitation of EIC waves is well below that for excitation of IA waves (assuming Maxwellian statistics) our results suggest a possible two step mechanism for destabilization of IA waves. Combining this simulation result with the observational fact that these EIC waves share a common phenomenology with the naturally enhanced IA lines (NEIALS) observed by incoherent scatter radars, especially that they both occur near field-aligned currents, leads to the proposition that this two-step mechanism is an alternative path to NEIALS.

Feasibility of Ion-cyclotron Resonant Heating in the Solar Wind

2021 ◽  
Author(s):  
Roberto E. Navarro ◽  
Victor Muñoz ◽  
Juan A. Valdivia ◽  
Pablo S. Moya
Keyword(s):  
Solar Wind ◽  
Solar Wind Plasma ◽  
Alpha Particles ◽  
Particle Interactions ◽  
Fermi Acceleration ◽  
Ion Cyclotron Waves ◽  
Proton Temperature ◽  
Propagating Waves ◽  
Ion Cyclotron ◽  
Cold Electrons

<p>Wave-particle interactions are believed to be one of the most important kinetic processes regulating the heating and acceleration of Solar Wind plasma. One possible explanation to the observed preferential heating of alpha (He<sup>+2</sup>) ions relies on a process similar to a second order Fermi acceleration mechanism. In this model, heavy ions are able to resonate with multiple counter-propagating ion-cyclotron waves, while protons can encounter only single resonances, resulting in the subsequent preferential energization of minor ions. In this work, we address and test this idea by calculating the number of plasma particles that are resonating with ion-cyclotron waves propagating parallel and anti-parallel to an ambient magnetic field in a proton/alpha plasma with cold electrons. Resonances are calculated through the proper kinetic multi-species dispersion relation of Alfven waves. We show that 100% of the alpha population can resonate with counter-propagating waves below a threshold ΔU<sub>αp</sub>/v<sub>A</sub><U<sub>0</sub>+a(β+β<sub>0</sub>)<sup>b</sup> in the differential streaming between protons and alpha particles, where U<sub>0</sub>=-0.532, a=1.211, β<sub>0</sub>=0.0275, and b=0.348 for isotropic ions. This threshold seems to match with constraints of the observed ΔU<sub>αp</sub> in the Solar Wind for low values of the proton plasma beta<strong>.</strong> Finally, it is also shown that this process is limited by the growth of plasma kinetic instabilities, a constraint that could explain alpha-to-proton temperature ratio observations in the Solar Wind at 1 AU.</p>

scholarly journals First results of low frequency electromagnetic wave detector of TC-2/Double Star program

2005 ◽  
Vol 23 (8) ◽  
pp. 2803-2811 ◽  
Author(s):  
J. B. Cao ◽  
Z. X. Liu ◽  
J. Y. Yang ◽  
C. X. Yian ◽  
Z. G. Wang ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Geomagnetic Storms ◽  
Low Frequency ◽  
Wave Detector ◽  
Ion Cyclotron Waves ◽  
Satellite Platform ◽  
Ion Cyclotron ◽  
First Results

Abstract. LFEW is a low frequency electromagnetic wave detector mounted on TC-2, which can measure the magnetic fluctuation of low frequency electromagnetic waves. The frequency range is 8 Hz to 10 kHz. LFEW comprises a boom-mounted, three-axis search coil magnetometer, a preamplifier and an electronics box that houses a Digital Spectrum Analyzer. LFEW was calibrated at Chambon-la-Forêt in France. The ground calibration results show that the performance of LFEW is similar to that of STAFF on TC-1. The first results of LFEW show that it works normally on board, and that the AC magnetic interference of the satellite platform is very small. In the plasmasphere, LFEW observed the ion cyclotron waves. During the geomagnetic storm on 8 November 2004, LFEW observed a wave burst associated with the oxygen ion cyclotron waves. This observation shows that during geomagnetic storms, the oxygen ions are very active in the inner magnetosphere. Outside the plasmasphere, LFEW observed the chorus on 3 November 2004. LFEW also observed the plasmaspheric hiss and mid-latitude hiss both in the Southern Hemisphere and Northern Hemisphere on 8 November 2004. The hiss in the Southern Hemisphere may be the reflected waves of the hiss in the Northern Hemisphere.

scholarly journals Ion cyclotron waves at Mars: Occurrence and wave properties

2014 ◽  
Vol 119 (7) ◽  
pp. 5244-5258 ◽  
Author(s):  
H. Y. Wei ◽  
M. M. Cowee ◽  
C. T. Russell ◽  
H. K. Leinweber
Keyword(s):  
Ion Cyclotron Waves ◽  
Ion Cyclotron ◽  
Wave Properties
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