Speaker
Dr
Irina Schweigert
(ITAM SB RAS)
Description
A series of stationary two-dimensional
(both parallel and transverse to the magnetic field) weak
double layers with three, four, or more potential steps
has been observed in a laboratory experiment in magnetized plasma
in Ref. [1].
In this work, we present the results of kinetic and experimental study
of the effect of magnetic
field configuration on the nonthermal plasma ($T_i$=0.1 eV, $T_e$=1-10 eV)
at low gas pressure (P=0.1 mTorr) bounded by cylindrical chamber.
The periodical plasma structures with peaked plasma density
were found both in 2D Particle in cell Monte Carlo collision
(PIC MCC) simulations
and in the experiment for the condition
when the electron Larmor radius is
comparable to the Debye length.
We calculated the electron and ion densities, charge distributions,
electrical potential distribution and etc for different
angles between magnetic field and wall.
We solved the system of equations which includes
Boltzmann equations for electron and ion distribution functions
(with elastic and inelastic collisions) and Poisson equation for
the electric potential distribution. The calculations were performed
with PlasmaNov code developed by Schweigert V. A. and Schweigert I. V.
(see, for example [2]) with PIC MCC method.
The intense electrical current was found to flow along the magnetic field
lines in narrow periodical channels.
The multiple weak double layers (electrical potential steps) were associated
with the peaked plasma (charge) distribution.
The transverse spatial size scales of the periodical plasma structure
depend on the oblique magnetic field magnitude (B $<$ 200G),
magnetic field angle relative to the axis of symmetry of the chamber
and mean electron energy.
1. T. Intrator, J. Menard, and N. Hershkowitz,
Multiple magnetized double layers in the laboratory
Physics of Fluids B 5, 806 (1993); doi: 10.1063/1.860933
2. I.V. Schweigert, S.J. Langendorf, M. L. R. Walker, M. Keidar,
Sheath structure transition controlled by secondary electron emission.
Plasma Sources Sci. Technol. 24 (2) (2015) 025012
Primary author
Dr
Irina Schweigert
(ITAM SB RAS)
Co-authors
Dr
Joseph Lukas
(GWU, Washington, USA)
Dr
Michael Keidar
(GWU, Washington, USA)
