scholarly journals INSTABILITIES INDUCED BY RESONANT ABSORPTION OF AN ELECTROMAGNETIC WAVE IN AN INHOMOGENEOUS PLASMA

1983 ◽  
Vol 44 (C2) ◽  
pp. C2-171-C2-179 ◽  
Author(s):  
J. C. Adam ◽  
A. Gourdin Servenière ◽  
G. Laval
Keyword(s):  
Electromagnetic Wave ◽  
Inhomogeneous Plasma ◽  
Resonant Absorption

Energy absorption in cold inhomogeneous plasmas: the Herlofson paradox

1972 ◽  
Vol 8 (3) ◽  
pp. 261-286 ◽  
Author(s):  
F. W. Crawford ◽  
K. J. Harker
Keyword(s):  
Energy Absorption ◽  
Inhomogeneous Plasma ◽  
Normal Modes ◽  
Delta Function ◽  
Underlying Mechanism ◽  
Resonant Absorption ◽  
Landau Damping ◽  
Dissipation Energy ◽  
Continuous Energy ◽  
Driving Signal

The Herlofson paradox is exemplified by a capacitor containing cold, collisionless, inhomogeneous plasma as the dielectric: its response to a sinusoidal driving signal can exhibit continuous energy absorption, even though the system is lossless. The underlying mechanism has been explained generally by Barston in terms of the transient response of the system. In this paper, we confirm Barston 's conclusions by examining in detail several analytically tractable cases of delta-function and sinusoidal excitation, and consider the effects of collisions and non-zero electron temperature in determining the steady state fields and dissipation. Energy absorption without dissipation in plasmas is analogous to that occurring after application of a signal to a network of lossless resonant circuits. This analogy is pursued, and extended to cover Landau damping in a warm homogeneous plasma, in which the resonating elements are the electron streams making up the velocity distribution. Some of the practical consequences of resonant absorption are discussed, together with a number of paradoxical plasma phenomena which can also be elucidated by considering a superposition of normal modes rather than a single Fourier component.

scholarly journals Coronal Heating Mechanism in the Presence of a Flow: A Numerical Approach

1998 ◽  
Vol 185 ◽  
pp. 469-470
Author(s):  
S. Parhi ◽  
T. Tanaka
Keyword(s):  
Magnetic Fields ◽  
Solar Corona ◽  
Plasma Heating ◽  
Inhomogeneous Plasma ◽  
Resonant Absorption ◽  
Numerical Approach ◽  
Coronal Heating ◽  
Heating Mechanism ◽  
Driving Current ◽  
Field Lines

The solar corona is a hot, tenuous plasma permeated with the structured magnetic fields. A variety of waves is generated in the corona due to the convective upwelling motion in the photosphere. The excitation of MHD fluctuations is generated by the footpoint motion of the field lines in the photosphere. Resonant absorption of the Alfvén waves in an inhomogeneous plasma has been suggested as a means of driving current and plasma heating in the corona (Sakurai et al., 1991). We study this problem in the presence of flow.

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