Analytic expression for mode conversion of Langmuir and electromagnetic waves

1989 ◽  
Vol 62 (23) ◽  
pp. 2680-2682 ◽  
Author(s):  
Denise E. Hinkel-Lipsker ◽  
Burton D. Fried ◽  
G. J. Morales
Keyword(s):  
Electromagnetic Waves ◽  
Mode Conversion ◽  
Analytic Expression

The theory of radio windows in planetary magnetospheres

1987 ◽  
Vol 412 (1842) ◽  
pp. 1-23 ◽  
Keyword(s):  
Plasma Wave ◽  
Electromagnetic Waves ◽  
Cold Plasma ◽  
Mode Conversion ◽  
Special Method ◽  
Concentration Gradients ◽  
Linear Mode ◽  
Full Wave ◽  
Warm Plasma ◽  
Partial Linear

The theory of radio windows given in two previous papers for a stratified cold plasma is extended to apply in a warm plasma. It is used to investigate one suggested mechanism for the production of non-thermal continuum radiation in magnetospheric cavities. The source is a plasma wave that enters a region where there is a gradient of electron concentration and there undergoes partial linear mode conversion to give ordinary and extraordinary electromagnetic waves and a reflected plasma wave. This theory is needed particularly for the plasmapause and magnetopause where the concentration gradients may be large. It is therefore necessary to use a full-wave integration of the governing differential equations. These are derived for a warm plasma. When they are integrated, the problem of numerical swamping is severe and is dealt with by a special method. Some typical results are presented and discussed.

Nonlinear electromagnetic waves in an inhomogeneous plasma

1992 ◽  
Vol 47 (1) ◽  
pp. 1-14
Author(s):  
Gabriele Cicconi
Keyword(s):  
Electromagnetic Waves ◽  
Ponderomotive Force ◽  
Mode Conversion ◽  
Inhomogeneous Plasma ◽  
Critical Conditions ◽  
Slab Geometry ◽  
Hydrodynamic Approximation ◽  
Varying Coefficients ◽  
Plasma Density Profile ◽  
Monochromatic Electromagnetic Wave

A stationary theoretical model giving an asymptotic description of the propagation of nonlinear electromagnetic waves in an inhomogeneous plasma is presented. The plasma, considered within the hydrodynamic approximation and assumed to be cold, collisionless, unmagnetized and electroneutral, is described in terms of a nonlinear dielectric function giving the effect of the Miller ponderomotive force. In an infinitely extended slab geometry, a variable transverse density gradient, assumed to be parabolic, is considered in the case when a monochromatic electromagnetic wave is incident upon the slab at an arbitrary angle. The transverse structure of the wave electric field is determined along with the perturbed plasma density profile. The nonlinear wave equation with slowly varying coefficients derived using this model is solved in first and second approximations using an asymptotic multiple-space-scale method due to Bogolyoubov and Mitropolskii. The critical conditions for resonant electrostatic absorption and mode conversion are derived and discussed within these approximations, and some reference numerical calculations are performed.

scholarly journals Mode Conversion and Reflection of Langmuir Waves in an Inhomogeneous Solar Wind

2001 ◽  
Vol 18 (4) ◽  
pp. 355-360 ◽  
Author(s):  
A. J. Willes ◽  
Iver H. Cairns
Keyword(s):  
Solar Wind ◽  
Electromagnetic Waves ◽  
Plasma Frequency ◽  
Mode Conversion ◽  
Langmuir Wave ◽  
Solar Wind Plasma ◽  
Langmuir Waves ◽  
Transverse Electromagnetic ◽  
Solar Wind Parameters ◽  
Conversion Efficiencies

AbstractBeam-driven Langmuir waves in the solar wind are generated just above the electron plasma frequency, which fluctuates in the inhomogeneous solar wind plasma. Consequently, propagating Langmuir waves encounter regions in which the wave frequency is less than the local plasma frequency, where they can be reflected, mode converted to transverse electromagnetic waves, and trapped in density wells. The aim here is to investigate Langmuir wave reflection and mode conversion at a linear density gradient for typical solar wind parameters. It is shown that higher mode conversion efficiencies are possible than previously calculated, but that mode conversion occurs in a smaller region of parameter space. In addition, the possibility of detecting mode conversion with in situ spacecraft Langmuir wave observations is discussed.

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