Hybrid simulations of intermediate shocks: Coplanar and noncoplanar solutions

Journal Article · Fri Sep 04 04:00:00 EDT 1992 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/92GL01994· OSTI ID:5213660

Karimabadi, H; Omidi, N ^[1]

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1. Univ. of California, San Diego, CA (United States)

The kinetic structure and stability of subfast intermediate shocks (IS) are investigated using a hybrid code. The shocks are formed dynamically by the interaction between a flowing plasma and a stationary piston. For [theta][sub BN] = 60[degrees] and plasma [beta] = 0.46, the strong IS is found to be stable with a width in the range of 10 to 20 ion inertial lengths ([lambda][sub i]). The rotation of the transverse component of the magnetic field is in the ion sense. The weak IS has a more complex structure and consists of both Alfven and slow waves. The leading edge of the shock is dominated by the Alfven mode and is associated with a S-shape electron sense field rotation with a small decrease (increase) in the magnetic field (density) across it. Some of the ion dissipation occurs within this layer, which is relatively thin ([approximately]17-20[lambda][sub i]). However, the transition to the downstream density and magnetic field occurs in the much wider ([approximately]150[lambda][sub i]) trailing slow wave. The main heating associated with this trailing edge occurs in the direction parallel to the magnetic field. This slow wave has a phase velocity larger than the Alfven speed due to kinetic corrections to linear wave properties. As a result, the slow wave stays attached to the leading edge of the shock which remains time-stationary. The classification of IS's, based on phase velocity on MHD modes, becomes ambiguous in the kinetic limit. When the magnetic field is noncoplanar, the strong IS becomes time-dependent and expands self-similarly in time, whereas the weak IS disintegrates into a rotational discontinuity (RD). 16 refs., 4 figs.

• OSTI ID: 5213660
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Journal Name: Geophysical Research Letters (American Geophysical Union); (United States) Vol. 19:17; ISSN GPRLAJ; ISSN 0094-8276
• Country of Publication: United States
• Language: English

Related Subjects

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Ionospheric
& Magnetospheric Phenomena-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COMPUTERIZED SIMULATION
MAGNETOPAUSE
PLASMA
SHOCK WAVES
SIMULATION
SOLAR ACTIVITY
SOLAR WIND