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Autori: Echim M., J. Lemaire
Editorial: Physical Review E, 72, p.036405, 2005.
We consider a two-dimensional stationary stream of a collisionless
plasma injected across an external stationary magnetic field
and a background stagnant plasma.
We compute the velocity distribution function (VDF) as well as the distribution of the
electromagnetic field consistent with this type of flow.
The solution is found by solving the Vlasov
equation for the VDF of each species (electrons and protons),
the Maxwell-Ampere equation for the magnetic vector potential and the equation of plasma quasi-neutrality
for the electrostatic potential.
The solution of the stationary Vlasov equation is given
in terms of two constants of motion and one adiabatic invariant.
The partial charge and current
densities are given by analytical expressions of the moments of the velocity distribution
functions for each particle species.
The 2D distribution of the plasma bulk velocity is
roughly uniform inside the jet.
There is no plasma bulk flow in the direction of the magnetic field.
Inside the boundary layer interfacing
the jet and the stagnant plasma, the bulk velocity has gradients
in the direction parallel as well perpendicular to the magnetic field.
The parallel component of this gradient, and the parallel gradient of the electron pressure
produce a non-zero electric field component parallel to the magnetic
field lines that is
a basic element allowing plasma elements to be transported across
magnetic field lines in astrophysical systems
as well as in laboratory experiments where plasmoids are injected across magnetic fields.
Cuvinte cheie: statistica, fizica neliniara // Statistical, nonlinear, soft matter physics