Self-consistent study of a perpendicular collisionless and nonresistive shock

Journal Article · Mon Jun 01 00:00:00 EDT 1987 · Phys. Fluids; (United States)

DOI:https://doi.org/10.1063/1.866191· OSTI ID:6488784

Lembege, B; Dawson, J M

Particle dynamics and field behavior associated with a perpendicular collisionless supercritical and viscous shock are investigated by use of numerical simulation. A one-dimensional, relativistic, fully electromagnetic and nonperiodic particle simulation code (for both electrons and ions) is used where self-consistent space-charge effects and induced effects are totally included. The principal field patterns of the shock (trailing wave train, ramp, and foot region) are studied in detail and are shown to have scale lengths mainly dictated by ion dynamics; the behavior of the corresponding plasma currents associated with the different field components is also presented. Ions are shown to suffer successive ''acceleration--trapping--detrapping'' at the shock front, and locally in the trailing wave train of the downstream region through combined effects of the electrostatic and magnetic fields. While detrapped, the reflected ions describe very large Larmor orbits and cause a ring distribution; a large rapid nonstochastic ion heating results from this ion gyration. This heating (resistivity-free) is the main source of dissipation and is responsible for large field damping. Competitive effects such as particle stochasticity, particle trapping, wave damping, wave overtaking, and dispersion effects are shown to interact with each other and to affect the overall dissipation mechanism. Comparison with previous works is also discussed. Various Mach number situations are considered, leading to the definition of a transitory regime between subcritical and supercritical regimes and of a corresponding critical threshold of the electrostatic field. In contrast with the supercritical regime, the subcritical regime is characterized by a low density of trapped-reflected ions, a broad ion distribution function with a weak tail, and a weak adiabatic bulk ion heating.

• Research Organization: Department of Physics, University of California, Los Angeles, California 90024
• OSTI ID: 6488784
• Journal Information: Phys. Fluids; (United States), Vol. 30:6
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
COLLISIONLESS PLASMA
SHOCK WAVES
ELECTROMAGNETISM
ELECTRONS
IONS
MAGNETIZATION
MAGNETOACOUSTIC WAVES
NONLINEAR PROBLEMS
NUMERICAL SOLUTION
ONE-DIMENSIONAL CALCULATIONS
PLASMA INSTABILITY
PLASMA SIMULATION
RELATIVISTIC PLASMA
SIMULATION
SPACE CHARGE
TURBULENCE
VISCOSITY
CHARGED PARTICLES
ELEMENTARY PARTICLES
FERMIONS
HYDROMAGNETIC WAVES
INSTABILITY
LEPTONS
MAGNETISM
PLASMA
700108* - Fusion Energy- Plasma Research- Wave Phenomena