Kelvin--Helmholtz vortex formation and particle transport in a cross-field plasma sheath. II. Steady state

摘要: The steady‐state behavior of the magnetized plasma–wall sheath has been studied through two‐dimensional particle simulations, which have shown that maintains itself in a strongly nonlinear, turbulent equilibrium, continuously driven by edge Kelvin–Helmholtz instability. assumes thickness order lx∼5ρi, and large, long‐lived vortices, with amplitudes δφ∼2.5Ti/e, drift parallel to wall at half ion thermal velocity. also spatially averaged potential drop from plasma Δφ≊−2Ti/e, opposite sign unmagnetized sheath. Accompanying long‐wavelength vortices are shorter‐wavelength fluctuations, induce an anomalous cross‐field transport, scaling accordance Bohm diffusion when ωpi≥2ωci. At lower densities, ωpi<2ωci, coefficient additional factor, proportional density. These results permit modeling simple effective boundar...