Cold Plasma Waves

ISBN-13: 9789024729777 / Angielski / Twarda / 1984 / 349 str.

H. G. Booker; Henry G. Booker

Opis

The book aims to present current knowledge concerning the propagation of electro- magnetic waves in a homogeneous magnetoplasma for which temperature effects are unimportant. It places roughly equal emphasis on the radio and the . hydromagnetic parts of the electromagnetic spectrum. The dispersion properties of a magnetoplasma are treated as a function both of wave frequency (assumed real) and of ionization density. However, there is little discussion of propagation in a stratified medium, for of collisions is included only which reference may be made to Budden 1] . The effect in so far as this can be done with simplicity. The book describes how pulses are radiated from both small and large antennas embedded in a homogeneous magneto- plasma. The power density radiated from a type of dipole antenna is studied as a function of direction of radiation in all bands of wave frequency. Input reactance is not treated, but the dependence of radiation resistance on wave frequency is described for the entire electromagnetic spectrum. Also described is the relation between beaming and guidance for Alfven waves.

Spis treści

1. Elementary properties of a plasma.- Plasma.- Equations of drift motion.- Isothermal atmosphere in equilibrium.- Types of wave.- Effect of collisions.- The continuity equations.- 2. Maxwell’s equations.- Equations in terms of current and charge densities.- Equations in terms of electric moment per unit volume.- The exponential wave function.- The concept of a dispersion relation.- Calculation of the dispersion relation (electric current method).- Calculation of the dispersion relation (electric moment method).- 3. Isotropic plasma.- Mobility and conductivity of an isotropic plasma.- Susceptibility and dielectric constant of a collisionless isotropic plasma.- The plasma frequency.- Refractive index of a collisionless isotropic plasma.- Wave dispersion in a collisionless isotropic plasma.- Effect of collisions in an isotropic plasma.- Importance of ordered kinetic energy in a plasma.- Poynting’s theorem in a plasma.- The energy significance of the complex dielectric constant of an isotropic plasma.- 4. Alternating current in a magnetoplasma.- Mobility tensor for a magnetoplasma.- Conductivity tensor for a magnetoplasma.- Low-frequency conduction properties of an infinite homogenous magnetoplasma.- Low-frequency conduction properties of a slab of magnetoplasma.- Effect of plasma scale on wave propagation.- 5. General properties of phase propagation in a magnetoplasma.- Susceptibility tensor for a magnetoplasma.- Alternative expressions for the susceptibility tensor components in the absence of multiple ion species.- Dispersion relation for a magnetoplasma.- Elliptic polarization.- Alternative derivation of the dispersion relation for a magnetoplasma.- The radio and hydromagnetic approximations.- Effect of collisions in a magnetoplasma.- 6. General properties of group propagation in a magnetoplasma.- Frequency and angular spectra.- Velocity of a wave packet.- Relation between phase and group propagation.- Method for calculating group velocity in a magnetoplasma.- Formulae for group velocity in a magnetoplasma.- Beam radiation in a magnetoplasma.- 7. Propagation of phase along the imposed magnetic field.- Circular polarization.- The dispersion relation for longitudinal propagation.- Longitudinal Alfvén waves.- The violin-string approach to longitudinal Alfven waves.- The hydromagnetic approximation for longitudinal propagation.- The radio approximation for longitudinal propagation.- The Eckersley approximation for longitudinal propagation.- Comparison of approximations.- Pass and stop bands of frequency for longitudinal propagation.- Particle vibration for longitudinal propagation.- Plasma motion in a longitudinal Alfvén wave.- Longitudinal propagation in low-density and high-density magnetoplasmas.- Effect of collisions on longitudinal propagation.- Effect of an additional ion species on longitudinal propagation.- Pass and stop bands of ionization density for longitudinal propagation.- 8. Energy flow and group velocity for longitudinal propagation.- Electromagnetic energy density for longitudinal propagation.- Kinetic energy density for longitudinal propagation.- Energy flow and group velocity for longitudinal propagation.- Energy in a longitudinal Alfvén wave.- Faraday rotation for longitudinal Alfvén waves.- A resonator for longitudinal Alfvén waves.- The mode of operation of a hydromagnetic violin-string.- Freezing of the magnetic field in the plasma (longitudinal Alfven waves).- Energy in a longitudinal whistler wave in the band ?Mi ? ? ? ?Me.- A resonator for longitudinal whistler waves in the band ?Mi ? ? ? ?Me.- Freezing of the magnetic field in the electron gas (longitudinal whistler wave).- Solid-state plasmas.- 9. Propagation of phase transverse to the imposed magnetic field.- The O wave.- The X wave.- Superposition of the O and X waves.- Pass and stop bands of frequency for transverse propagation.- The hybrid resonant frequencies.- Transverse propagation in a low-density magnetoplasma.- Pass and stop bands of ionization density for transverse propagation.- Effect of collisions on transverse propagation.- 10. Elliptic polarization of the X wave for transverse propagation.- The electric ellipse for transverse propagation of the X wave.- Frequency dependence of the electric ellipse.- Particle vibration for transverse propagation of the X wave.- Plasma compressions and dilations for transverse propagation of the X wave.- Non-reciprocity.- 11. Energy behaviour of the X wave for transverse propagation.- Electromagnetic energy density for transverse propagation of the X wave.- Kinetic energy density for transverse propagation of the X wave.- Energy flow and group velocity for transverse propagation of the X wave.- A resonator for transverse Alfvén waves.- The mode of operation of a hydromagnetic organ-pipe.- Freezing of the magnetic field in the plasma (transverse Alfvén waves).- 12. Propagation at any angle to the imposed magnetic field..- The zeros in the frequency dispersion curves.- Nomenclature for the characteristic waves.- The cross-connection phenomenon for frequency dispersion curves.- Frequency dispersion curves for nearly transverse propagation.- Frequency dispersion curves for nearly longitudinal propagation.- The elliptic polarizations of the O and X waves at the plasma frequency.- Effect of an additional ion species on cross-connection phenomena.- The infinities in the frequency dispersion curves.- Permitted regions for the frequency dispersion curves.- The cross-connection phenomenon for ionization dispersion curves.- Permitted regions for the ionization dispersion curves.- Propagation into a magnetoplasma from free space.- 13. The radio approximation.- The radio approximation to the dispersion relation.- Frequency dispersion curves in the radio band.- Frequency dependence of elliptic polarization in the radio band.- Frequency dependence of the direction of group propagation in the radio band.- Variation in the angle of squint of a rotating broadside antenna in the radio band.- Dependence of refractive index on ionization density in the radio band.- Dependence of elliptic polarization on ionization density in the radio band.- Dependence of the direction of group propagation on ionization density in the radio band.- 14. The hydromagnetic approximation.- The hydromagnetic approximation to the dispersion relation.- Frequency dispersion curves in the hydromagnetic band.- Effect of ionic collisions in the hydromagnetic band.- The fit between the hydromagnetic and radio approximations.- Frequency dependence of elliptic polarization in the hydromagnetic band.- Frequency dependence of the tilts of the electronic and current ellipses in the hydromagnetic band.- Frequency dependence of the direction of group propagation in the hydromagnetic band.- Polar diagrams for group velocity in the hydromagnetic band.- Dependence of refractive index on ionization density in the hydromagnetic band.- Dependence of elliptic polarization on ionization density in the hydromagnetic band.- Dependence of the direction of group propagation on ionization density in the hydromagnetic band.- 15. The quasi-longitudinal and quasi-transverse approximations.- The transition angle between the quasi-longitudinal and quasi-transverse approximations.- The regions of validity for the first- order angular approximations.- Importance of avoiding angular approximations that upset an infinity of a refractive index.- The regions of validity for angular approximations of practical value.- Accuracy of ?2n/??p2 using angular approximations.- The quasi-transverse approximation when ? ? ?Mi.- The quasi-longitudinal approximation when ? ? Max(?N,?Me).- The quasi-longitudinal approximation when ?Mi ? ? < ?Me ? ?N.- Group propagation for the whistler wave when ??1 ? ? < ?Me ? ?N.- Comparison of the zero-order quasi-longitudinal approximation in the whistler band with the unapproximated formulae.- 16. Directional behaviour of group velocity in a magnetoplasma.- Group propagation of the X wave in the pass band ? > ?C2.- Group propagation of the O wave in the pass band ? > ?N.- Group propagation in the upper part of the whistler band [??1 < ? < Min(?N,?Me)].- Group propagation in the lower part of the whistler band (? ? ??1).- Group propagation of the O wave in the pass band ? < ?Mi.- Group propagation of the X wave in the pass band ?C1 ?Me.- Group propagation of the X wave in the pass band ?C1 < ? < ??2 when ?N < ?Me.- 17. The field of an antenna in a magnetoplasma.- Axes of coordinates.- Angular spectra of O and X waves.- The predominant directions of group and phase propagation in the far field.- The method of steepest descent.- Simplification of the notation.- The power density in the far field.- Use of the angle of phase propagation as an independent variable.- Radiation from a gaussian dipole in a homogeneous magnetoplasma.- A reference isotropic medium.- Radiation ?C2.- Radiation in the frequency band ?C2 > ? > ??2.- Radiation in the frequency band ?? > ? > ?N.- Radiation in the frequency band ?N > ? > ?C1.- Radiation in the frequency band ?Me > ? > ??1.- Radiation in the frequency band ??1 > ? > ?Mi.- Radiation in the frequency band ? < ?Mi.- Frequency dependence of radiation resistance.- The relation between beaming and guidance in a homogeneous magnetoplasma.- The relation between beaming and guidance for the whistler wave when ??1 < ? ? Min (?N, ?Me).- The relation between beaming and guidance for the O wave when ? ? ?Mi.- The relation between beaming and guidance for the combined O and X waves when ? ? ?Mi.- Effect of energy absorption on Alfvén guidance.- Symbols.- Index of subjects.