Wavelength and decay length of density overshoot structure in supercritical, collisionless bow shocks

Journal Article · Sun May 15 04:00:00 EDT 2005 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.1900093· OSTI ID:20722103

Saxena, R; Bale, S D; Horbury, T S ^[1]

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1. Department of Physics and Space Sciences Laboratory, University of California, Berkeley, California 94720-7450 (United States)

Above some critical Mach number, quasiperpendicular collisionless shocks are known to exhibit 'overshoot' and 'undershoot' structure thought to be associated with the motion of ions trapped at the shock front. Using spacecraft potential data from the Cluster spacecraft, the overshoot/undershoot density structure at 56 crossings of the quasiperpendicular bow shock is studied. The envelope of the absolute value of the density, in most cases, decays exponentially and these envelopes are fitted to a decaying function from which we calculate the decay length scale. The overshoot/undershoot wavelength is also estimated using the zero crossings of the density profile and a good correlation between the average wavelength and the convected ion gyroradius is found: the wavelength is approximately two to three times the ion gyroradius. There is no evidence of a strong correlation between the wavelength and the ion inertial length. Similar results are found for the decay length, which also seems to be ordered by the convected ion gyroradius.

• OSTI ID: 20722103
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 5 Vol. 12; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
MACH NUMBER
PLASMA
PLASMA DENSITY
SHOCK WAVES
SOLAR WIND
WAVELENGTHS