Fully kinetic plasma-sheath theory for a cold-electron emitting surface

Publisher Website
Google Scholar
Abstract
The fully kinetic, one‐dimensional, plasma‐sheath theory by Schwager and Birdsall [Phys. Fluids B 2, 1057 (1990)] is further developed. A cold‐electron emitting surface is included and a three‐dimensional plasma is considered. The sheath potential is not assumed to equal the floating potential so that the theory applies to a current‐carrying sheath. Appropriate values are found for higher‐order moments of the velocity distribution which depend on the three‐dimensional velocity distribution width. Distribution functions in terms of energy and angle are derived. The (effective) temperature, the total energy flux, and the heat flux are evaluated in terms of exact analytic functions. The normalized magnitude of the floating potential for a deuterium plasma with equal ion and electron temperatures is calculated to be ψf=3.2 for δ=0 and ψf=1.8 for δ=0.75 where δ is the electron emission coefficient. The normalized magnitude of the sheath potential for the same plasma (with δ=0) is calculated to be ψs=3.9 for γ=0.02 and ψs=2.8 for γ=−0.02 where γ is the normalized current density. A self‐consistent integral solution for the electrostatic potential profile within the sheath is derived.

This publication has 3 references indexed in Scilit: