High-frequency flute instability with loss-cone distribution function

1976 ◽  
Vol 19 (2) ◽  
pp. 272 ◽  
Author(s):  
A. Hirose
1976 ◽  
Vol 15 (3) ◽  
pp. 325-333 ◽  
Author(s):  
L. Gomberoff ◽  
S. Cuperman

It is shown that an ion loss cone distribution function with m ≥ 1 becomes unstable against electrostatic waves with ω ≫ Ωp and k0 = 0 in the presence of a cold plasma population, in contrast with pure warm systems, which require m ≥ 3 for instability. This result is an extension to high frequencies, ω ≫ Ω of similar conclusions reached by Pearlstein et al. (1966) and Farr & Budwine (1968), for ω-values equal to the first few harmonics of the proton gyrofrequency.


1975 ◽  
Vol 39 (3) ◽  
pp. 795-802 ◽  
Author(s):  
Yoshihide Yamamoto ◽  
Shun-Ichi Kishimoto ◽  
Hideo Akimune ◽  
Tokuo Suita

2007 ◽  
Vol 73 (6) ◽  
pp. 981-992 ◽  
Author(s):  
O. A. POKHOTELOV ◽  
O.G. ONISHCHENKO ◽  
M. A. BALIKHIN ◽  
L. STENFLO ◽  
P. K. SHUKLA

AbstractThe nonlinear theory of large-amplitude magnetosonic (MS) waves in highβ space plasmas is revisited. It is shown that solitary waves can exist in the form of ‘bright’ or ‘dark’ solitons in which the magnetic field is increased or decreased relative to the background magnetic field. This depends on the shape of the equilibrium ion distribution function. The basic parameter that controls the nonlinear structure is the wave dispersion, which can be either positive or negative. A general dispersion relation for MS waves propagating perpendicularly to the external magnetic field in a plasma with an arbitrary velocity distribution function is derived.It takes into account general plasma equilibria, such as the Dory–Guest–Harris (DGH) or Kennel–Ashour-Abdalla (KA) loss-cone equilibria, as well as distributions with a power-law velocity dependence that can be modelled by κdistributions. It is shown that in a bi-Maxwellian plasma the dispersion is negative, i.e. the phase velocity decreases with an increase of the wavenumber. This means that the solitary solution in this case has the form of a ‘bright’ soliton with the magnetic field increased. On the contrary, in some non-Maxwellian plasmas, such as those with ring-type ion distributions or DGH plasmas, the solitary solution may have the form of a magnetic hole. The results of similar investigations based on nonlinear Hall–MHD equations are reviewed. The relevance of our theoretical results to existing satellite wave observations is outlined.


2007 ◽  
Vol 73 (2) ◽  
pp. 207-214 ◽  
Author(s):  
R. P. SINGHAL ◽  
A. K. TRIPATHI

Abstract.The components of the dielectric tensor for the distribution function given by Leubner and Schupfer have been obtained. The effect of the loss-cone index appearing in the particle distribution function in a hot magnetized plasma has been studied. A case study has been performed to calculate temporal growth rates of Bernstein waves using the distribution function given by Summers and Thorne and Leubner and Schupfer. The effect of the loss-cone index on growth rates is found to be quite different for the two distribution functions.


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