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Collisionless slow shocks in magnetotail reconnection
Author(s) -
Cremer Michael,
Scholer Manfred
Publication year - 1999
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 - 10.1029/1999gl900592
Subject(s) - physics , current sheet , magnetic reconnection , cyclotron , instability , bow wave , lower hybrid oscillation , bow shock (aerodynamics) , magnetic field , plasma , magnetosheath , atomic physics , computational physics , magnetohydrodynamics , shock wave , magnetosphere , magnetopause , solar wind , mechanics , quantum mechanics
The kinetic structure of collisionless slow shocks in the magnetotail is studied by solving the Riemann problem of the collapse of a current sheet with a normal magnetic field component using 2‐D hybrid simulations. The collapse results in a current layer with a hot isotropic distribution and backstreaming ions in a boundary layer. The lobe plasma outside and within the boundary layer exhibits a large perpendicular to parallel temperature anisotropy. Waves in both regions propagate parallel to the magnetic field. In a second experiment a spatially limited high density beam is injected into a low beta background plasma and the subsequent wave excitation is studied. A model for slow shocks bounding the reconnection layer in the magnetotail is proposed where backstreaming ions first excite obliquely propagating waves by the electromagnetic ion/ion cyclotron instability, which lead to perpendicular heating. The T ⟂ / T ∥ temperature anisotropy subsequently excites parallel propagating Alfvén ion cyclotron waves, which are convected into the slow shock and are refracted in the downstream region.