Other
Scientific paper
Apr 1994
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994jgr....99.6609s&link_type=abstract
Journal of Geophysical Research (ISSN 0148-0227), vol. 99, no. A4, p. 6609-6635
Other
30
Collisionless Plasmas, Electron Distribution, Electron Plasma, Magnetohydrodynamic Stability, Magnetosonic Resonance, Shock Waves, Particle Density (Concentration), Self Consistent Fields, Wave Propagation
Scientific paper
Two- and one-dimensional fully electromagnetic, bounded, particle (for both electrons and ions) codes are used in order to study electron dynamics in collisionless magnetosonic shocks propagating in supercritical regime and quasi-perpendicular direction (90 deg greater than theta (sub zero) greater than 45 deg); theta (sub zero) is the angle between the shock normal and the upstream magnetic field. The purpose of the study consists in comparing electrons behavior in one-dimensional ('pseudo-oblique') nonresistive shocks and in two-dimensional resistive oblique shocks. Resistive effects related to plasma microinstabilities can be self-consistently included in two-dimensional particle codes in contrast with one-dimensional particle codes. Present two-dimensional results reproduce local electron distribution functions (in particular, downstream 'flat tops') in a self-consistent way and in good agreement with observational results. On the other hand, one-dimensional results exhibit either local wenlarged Maxwellian distributions with a partial tail, or a flat top distribution according to the particle density n. These results emphasize that (1) the differences observed between one- and two-dimensional codes may be explained in terms of a critical particle density n (sub c) used in the one-dimensional code; (2) the evidence of flat tops in both two- and one-dimensional results (provided that n greater than n(sub c)) proves that the macroscopic potential jump at the shock front is mainly responsible for their formation; (3) m icroscopic effects (herein related to the self-consistent cross-field/field-aligned currents instabilities) may represent a complementary mechanism for filling the flat top distribution; (4) some relaxation of the unstable electron flat top distribution (T(sub parallel)/T(sub perpendicular to) much greater than 1) is observed when penetrating further into the downstream region, which means that the main filling mechanisms are localized in the ramp of the shock. Moreover, a detailed study of two-dimensional results shows that both resistive and nonresistive configurations can be easily distinguished for theta (sub zero) approximately equals 90 degs, but not any more for large deviations of theta (sub zero) from 90 degs, for which the self-consistent magnetic field rotates noticeably out of the coplanarity plane at the shock front.
Lembege Bertand
Savoini Philippe
No associations
LandOfFree
Electron dynamics in two- and one-dimensional oblique supercritical collisionless magnetosonic shocks does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Electron dynamics in two- and one-dimensional oblique supercritical collisionless magnetosonic shocks, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electron dynamics in two- and one-dimensional oblique supercritical collisionless magnetosonic shocks will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1259087