Physics
Scientific paper
Mar 1995
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995jgr...100.3601p&link_type=abstract
Journal of Geophysical Research (ISSN 0148-0227), vol. 100, no. A3, p. 3601-3611
Physics
19
Collisionless Plasmas, Current Sheets, Earth Magnetosphere, Magnetic Equator, Magnetic Field Reconnection, Shear Layers, Tearing Modes (Plasmas), Computerized Simulation, Electron Mass, Equilibrium Equations, Gyrofrequency, Ion Exchanging, Particle Trajectories
Scientific paper
Two-dimensional (x,z) particle simulations are used to investigate the influence of a minimum in the equatorial magnetic field profile and of a B(sub y) field component (sheared magnetic field) on the occurrence of collisionless reconnection in thin current sheets (R(sub i)/L is approximately 1, where R(sub i) is the ion gyroradius based on the lobe field B(sub 0) and L is the current sheet half thickness). It is shown that the pure ion tearing mode (ion to electron mass ratio M(sub i)/m(sub e) = 1) first produces an X line in a region of minimum average (over a tearing wavelength) normal field B(sub z) (x,0) and in the region of minimum current sheet thickness; this need not coincide with the actual minimum in B(sub z). With a mass ratio M(sub i)/m(sub e) greater than 1 the tearing growth rate is strongly reduced as krho(sub e) tends towards 1, where rho(sub e) is the electron gyroradius in the B(sub z) field. This is an extension of the stabilization associated with electron confinement to a flux tube previously predicted and observed for a constant equatorial field profile. If the slow growth allowed for krho(sub e) greater than or approximately = 1 eventually produces an X line, then an 'explosive' stage of reconnection occurs in which the electron dynamics no longer exhibits the tearing mode displacement, and the growth rate approaches that for the one-dimensional neutral sheet. The addition of a uniform and static shear field B(sub y) greater than or approximately = B(sub z) is found not to remove the stabilizing effect associated with the electron dynamics. The significant differences between the parameter regime of the present simulations and that of analytic treatments of the effect of B(sub y) on thick (R(sub i)/L less than 0.1) current sheets are discussed in detail.
Büchner Jörg
Pritchett Philip L.
No associations
LandOfFree
Collisionlessf reconnection in configurations with a minimum in the equatorial magnetic field and with magnetic shear 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 Collisionlessf reconnection in configurations with a minimum in the equatorial magnetic field and with magnetic shear, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Collisionlessf reconnection in configurations with a minimum in the equatorial magnetic field and with magnetic shear will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-844857