Magnetic reconnection in a non-Maxwellian neutral sheet. Interim report

Technical Report · Fri May 30 04:00:00 EDT 1986

OSTI ID:5383381

Chen, J; Palmadesso, P J; Lee, Y C

The collisionless tearing-mode instability is believed to play an important role in magnetospheric reconnection processes. It has been found that the linear growth rate for a non-Maxwellian neutral sheet can be enhanced by a few orders of magnitude in comparison with the conventional isotropic case and that the short-wavelength perturbations (k delta is greater than 1) are strongly favored, where delta is the characteristic half-width of the neutral sheet. For typical magnetotail parameters, it is found that the linear e-folding time can be reduced to a small function of a minute. The resulting small-scale islands are expected to coalesce rapidly. The additional free energy is the particle energy is the form of non-Maxwellian distribution. Differential-equation analysis and full integro-differential analysis using exact unperturbed orbits are discussed. Physically, if non-Maxwellian features are generated in the plasma distribution by changes in external conditions such as the solar wind conditions, then the magnetotail may become strongly unstable, resulting in rapid development of small-scale islands, coalescence, and reconnection. This process may manifest itself as triggering of substorms following such changes.

• Research Organization: Naval Research Lab., Washington, DC (USA)
• OSTI ID: 5383381
• Report Number(s): AD-A-168858/9/XAB; NRL-MR-5787
• Country of Publication: United States
• Language: English

Related Subjects

640203* -- Atmospheric Physics-- Magnetospheric Phenomena-- (-1987)
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107 -- Fusion Energy-- Plasma Research-- Instabilities
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COALESCENCE
COLLISIONLESS PLASMA
DIFFERENTIAL EQUATIONS
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
EQUATIONS
INSTABILITY
MAGNETIC RECONNECTION
MAGNETIC STORMS
MAGNETOTAIL
PLASMA
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
PLASMASPHERE
SOLAR ACTIVITY
SOLAR WIND
TEARING INSTABILITY