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Title: The effects of strong temperature anisotropy on the kinetic structure of collisionless slow shocks and reconnection exhausts. I. Particle-in-cell simulations

Journal Article · · Physics of Plasmas
DOI:https://doi.org/10.1063/1.3601760· OSTI ID:21546940
; ;  [1]
  1. University of Maryland, College Park, Maryland 20742 (United States)

A 2-D Riemann problem is designed to study the development and dynamics of the slow shocks that are thought to form at the boundaries of reconnection exhausts. Simulations are carried out for varying ratios of normal magnetic field to the transverse upstream magnetic field (i.e., propagation angle with respect to the upstream magnetic field). When the angle is sufficiently oblique, the simulations reveal a large firehose-sense (P{sub ||}>P{sub perpendicular}) temperature anisotropy in the downstream region, accompanied by a transition from a coplanar slow shock to a non-coplanar rotational mode. In the downstream region the firehose stability parameter {epsilon}=1-{mu}{sub 0}(P{sub ||}-P{sub perpendicular})/B{sup 2} tends to plateau at 0.25. This balance arises from the competition between counterstreaming ions, which drive {epsilon} down, and the scattering due to ion inertial scale waves, which are driven unstable by the downstream rotational wave. At very oblique propagating angles, 2-D turbulence also develops in the downstream region.

OSTI ID:
21546940
Journal Information:
Physics of Plasmas, Vol. 18, Issue 6; Other Information: DOI: 10.1063/1.3601760; (c) 2011 American Institute of Physics; ISSN 1070-664X
Country of Publication:
United States
Language:
English