Dielectric current in a plasma
- National Aeronautics and Space Administration, Goddard Space Flight Center, Code 910.4, Greenbelt, Maryland 20771 (United States)
The {open_quote}{open_quote}dielectric{close_quote}{close_quote} current driven by a spatially dependent, suddenly applied, electric field {bold E} orthogonal ({perpendicular}) to the magnetic induction {bold B} in a collisionless plasma is investigated from first principles. Both {bold E} and {bold B} are assumed in fixed directions. The current is qualitatively different in two conditions, whether {bold {nabla}}{ital E}{lt}{ital B}{sup 2}{ital q}/{ital mc}{sup 2} or {bold {nabla}}{ital E}{approx_gt}{ital B}{sup 2}{ital q}/{ital mc}{sup 2} [K. D. Cole, Planet. Space Sci. {bold 24}, 515 (1976)], where {ital q} and {ital m} are the charge and mass, respectively, of charged particles. Here the current is verified in the first condition by a new argument. Nonadiabatically (NA) established uniform electric field orthogonal to a magnetic field causes an additional time-averaged pressure in the plasma, given by {rho}{sub {ital mc}}{sup 2}{ital E}{sup 2}/2{ital B}{sup 2}, where {rho}{sub {ital m}} is the mass density of the plasma, and a consequent accompanying additional magnetic moment per unit volume, given by {minus}{rho}{sub {ital mc}}{sup 2}{ital E}{sup 2}/2{ital B}{sup 3}. When the electric field has a gradient parallel to the field itself, there is produced a dielectric current which is balanced by a grad{ital p} current due to the pressure caused by the electric field. This analysis of the NA case leads to the identification of div{bold D}{sub {perpendicular}}, rather than div{bold E}{sub {perpendicular}}, with the net charge density, consistent with the Jean{close_quote}s theorem of the equivalence of free particle orbit theory with the collisionless Boltzmann equation. (Abstract Truncated)
- OSTI ID:
- 285590
- Journal Information:
- Physics of Plasmas, Vol. 3, Issue 7; Other Information: PBD: Jul 1996
- Country of Publication:
- United States
- Language:
- English
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