Theory and simulation of collisionless parallel shocks

Journal Article · Thu Sep 01 04:00:00 EDT 1988 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA093iA09p09649· OSTI ID:6919954

Quest, K B

A one-dimensional theory of shocks propagating parallel to the ambient magnetic field in a collisionless plasma is presented. We show that shock formation and plasma heating can result from parallel propagating electromagnetic ion beam-driven instabilities for a wide range of Mach numbers and upstream plasma conditions. The plasma upstream from a parallel shock overtakes the slower, downstream plasma in the absence of any electrostatic or electromagnetic wave fields. An interface region is created that is unstable to electromagnetic ion beam-driven growth. The waves grow until they can scatter and couple the upstream and downstream plasma populations and can provide the necessary entropy increase for the shock. The marginal firehose state is reached downstream from the shock if the Alfven Mach number M/sub A/ is high enough (M/sub A/equivalentU/sub u//C/sub A/, where U/sub u/ is the upstream shock velocity and C/sub A/ is the upstream Alfven speed). A one-dimensional compression of the ions along the magnetic field line direction results for weaker shocks. We solve a set of jump conditions and show that the marginal firehose state is first reached at a small magnetosonic Mach number (less than 2). We derive various conditions for creating and maintaining the shock via the ion beam-driven instability and show that these conditions are roughly equal.

• Research Organization: Inertial Fusion and Plasma Theory, Applied Theoretical Physics Division, Los Alamos National Laboratory, Los Alamos, New Mexico
• OSTI ID: 6919954
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 93:A9; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640104 -- Astrophysics & Cosmology-- Solar Phenomena
640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COLLISIONLESS PLASMA
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
HEATING
INSTABILITY
INSTABILITY GROWTH RATES
INTERPLANETARY SPACE
MACH NUMBER
ONE-DIMENSIONAL CALCULATIONS
PLASMA
PLASMA HEATING
PLASMA INSTABILITY
SHOCK WAVES
SOLAR ACTIVITY
SOLAR WIND
SPACE
VELOCITY
WAVE PROPAGATION