Open AccessA theoretical and simulation study of the contact discontinuities based on a Vlasov simulation code
Author(s) -
Tsai T. C.,
Lyu L. H.,
Chao J. K.,
Chen M. Q.,
Tsai W. H.
Publication year - 2009
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2009ja014121
Subject(s) - vlasov equation , physics , electron temperature , magnetohydrodynamics , classification of discontinuities , electron , heat flux , mechanics , particle in cell , oscillation (cell signaling) , boundary value problem , instability , plasma , heat transfer , chemistry , quantum mechanics , mathematics , mathematical analysis , biochemistry
Contact discontinuity (CD) is the simplest solution that can be obtained from the magnetohydrodynamics (MHD) Rankine‐Hugoniot jump conditions. Due to the limitations of the previous kinetic simulation models, the stability of the CD has become a controversial issue in the past 10 years. The stability of the CD is reexamined analytically and numerically. Our theoretical analysis shows that the electron temperature profile and the ion temperature profile must be out of phase across the CD if the CD structure is to be stable in the electron time scale and with zero electron heat flux on either side of the CD. Both a newly developed fourth‐order implicit electrostatic Vlasov simulation code and an electromagnetic finite‐size particle code are used to examine the stability and the electrostatic nature of the CD structure. Our theoretical prediction is verified by both simulations. Our results of Vlasov simulation also indicate that a simulation with initial electron temperature profile and ion temperature profile varying in phase across the CD will undergo very transient changes in the electron time scale but will relax into a quasi‐steady CD structure within a few ion plasma oscillation periods if a real ion‐electron mass ratio is used in the simulation and if the boundary conditions allow nonzero heat flux to be presented at the boundaries of the simulation box. The simulation results of this study indicate that the Vlasov simulation is a powerful tool to study nonlinear phenomena with nonperiodic boundary conditions and with nonzero heat flux at the boundaries of the simulation box.