Ion dynamics in high-mach-number quasi-parallel shocks

Journal Article · Mon Nov 01 04:00:00 EST 1993 · Journal of Geophysical Research

DOI:https://doi.org/10.1029/93JA01423· OSTI ID:146547

Lyu, L H ^[1]; Kan, J R ^[2]

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1. National Central Univ., Taiwan (China)
2. Univ. of Alaska, Fairbanks, AK (United States)

Ion heating in high-Mach-number (M{sub A}{>=}3) quasi-parallel shocks is accomplished by ion reflections at the shock ramp and nonadiabatic pitch angle scattering through nonlinear waves in the shock transition region. Two types of ion reflection events are observed in high-Mach-number shock simulations: (1) the reflecting-reentering event and (2) the backstreaming-gyrating event. The behavior of ion reflection depends on the orientation of the ramp field to the upstream field. A gyroreflection model is proposed to provide a physical explanation for the two types of ion reflection events observed in the high-Mach-number shocks. The rotation of the ramp field with time leads to alternative occurrence of the two types of ion reflection events, which in turn leads to shock front reformation in the high-Mach-number shocks. The rotation of the ramp field with time leads to alternative occurrence of the two types of ion reflection events, which in turn leads to alternative occurrence of the two types of ion reflection events, which in turn leads to shock front reformation in the high-Mach-number quasi-parallel shock. The time scale for the shock front reformation is estimated to be about 1 to 2 upstream ion gyroperiods, which is about 10 ion gyroperiods for ions experiencing overshot magnetic field in the shock ramp. 36 refs., 11 figs., 1 tab.

• Sponsoring Organization: USDOE
• OSTI ID: 146547
• Journal Information: Journal of Geophysical Research, Journal Name: Journal of Geophysical Research Journal Issue: A11 Vol. 98; ISSN JGREA2; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
DYNAMICS
HEATING
IONS
MACH NUMBER
SHOCK WAVES