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A hybrid simulation of contact discontinuity
Author(s) -
Wu B. H.,
Chao J. K.,
Tsai W. H.,
Lin Y.,
Lee L. C.
Publication year - 1994
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/94gl01579
Subject(s) - classification of discontinuities , discontinuity (linguistics) , ion , electric field , electron , plasma , materials science , atomic physics , electron density , physics , condensed matter physics , mathematical analysis , mathematics , quantum mechanics
Contact discontinuities in a collisionless plasma are studied by hybrid simulations, in which ions are treated as particles and electrons are considered as a fluid. It is demonstrated that contact discontinuity with a stable density ramp can exist in cases with a finite electron temperature. An electron pressure gradient is present across the contact discontinuity, leading to the presence of a parallel electric field and hence field‐aligned potential increase (ΔΦ ∥ ) in the transition region. By reflecting ions at the discontinuity, this parallel electric potential peak reduces the interpenetration between hot and cold ions and maintains a stable density ramp across the contact discontinuity. The ratio of the field‐aligned electric potential energy to ion thermal energy, e ΔΦ ∥ / kT i , is found to be an increasing function of T e / T i , where T e and T i are respectively the electron and ion temperature.