PLASMA OSCILLATIONS AND DISPERSION IN THE PRESENCE OF A MAGNETIC FIELD

Technical Report · Wed Nov 26 04:00:00 EST 1958

OSTI ID:4273840

Kantor, M

A study is made of harmonic oscillations which may exist in a fully ionized, collision-free, homogeneous plasma subjected to a steady magnetic field. The plasma consists of a binary mixture of electrons and ions for which electrical neutrality is preserved. The system is described by writing the Maxwell second-order electrodynamic wave equation and the linearized equations of macroscopic motion of the particles. By transforming the vector equations to a homogeneous set of scalar algebraic equations and equating the determinant of the system to zero, one obtains for the characteristic aquation of the plasma a quartic in the square of the propagation vector. This fourth degree polynomial implies, in general, the existence of four distinct modes of plasma wave propagation. It is shown that the various kinds of hydromagnetic waves, including positive-ion oscillations and Alfven waves, all belong to the fundamental or lowest of the four modes of propagation. In general, the group and phase velocities are frequency dependent (the medium is dispersive) and are complicated functions of the angle B between the steady magnetic field and the propagation vector or wave normal. For the limiting angles = 0, The effects of /2, the quartic can be factored and the roots calculated explicitly, leading to precise dispersion formulas in agreement with known results. For intermediate angles the factorization is discouragingly complex. However, an approximation for the fundamental mode is given and yields dispersion formulas valid for arbitrary . (auth)

• Research Organization: Space Technology Labs., Inc. Physical Research Lab., Los Angeles
• NSA Number: NSA-13-011975
• OSTI ID: 4273840
• Report Number(s): NP-7473; GM-TR-0165-00526
• Country of Publication: United States
• Language: English

Related Subjects

ALFVEN WAVES
ANGULAR DISTRIBUTION
DIFFRACTION
ELECTRODYNAMICS
ELECTROMAGNETIC WAVES
ELECTRONS
EQUATIONS
FLUID FLOW
FREQUENCY
HOMOGENEOUS REACTORS
IONIZATION
IONS
MAGNETIC FIELDS
MATRICES
MAXWELL EQUATIONS
MIXING
MOTION
OSCILLATIONS
PHYSICS AND MATHEMATICS
PLASMA
VECTORS
VELOCITY
WAVE PROPAGATION