Collisional transport treatment of surface plasma structures
| Autor: | L. M. Montierth, W. A. Neuman, R. L. Morse |
|---|---|
| Rok vydání: | 1989 |
| Předmět: |
Fluid Flow and Transfer Processes
Physics Computational Mechanics General Physics and Astronomy Electron Plasma Condensed Matter Physics Thermal conduction Kinetic energy Ion Distribution function Physics::Plasma Physics Mechanics of Materials Quantum mechanics Fokker–Planck equation Atomic physics Electron ionization |
| Zdroj: | Physics of Fluids B: Plasma Physics. 1:1911-1925 |
| ISSN: | 0899-8221 |
| Popis: | Calculations are shown of the structure of plasmas in equilibrium with solid surfaces that reemit incident plasma ions as relatively cold neutral gas. A numerical transport model that includes a Fokker–Planck treatment of ion–ion collisions obtains the distribution function for ions in a phase space of one spatial coordinate and two velocities. This is done self‐consistently with an electrostatic potential, a Maxwell–Boltzmann description of electrons, and electron impact ionization of the reemited neutrals. Solutions are obtained from a higher temperature kinetic regime where Coulomb collisions are nearly negligible to a lower temperature regime where plasma behavior is approximately fluidlike. A result of these calculations is the resolution of an ambiguity posed by previous kinetic regime calculations that omitted ion–ion collisions and obtained a family of solutions for each set of physical parameters [Phys. Rev. Lett. 49, 650 (1982); Phys. Fluids B 1, 448 (1989)]. The physically correct solution for semi‐infinite surface plasmas is shown to be the member of each family that maximizes the ion thermal conduction to the surface and the magnitude of a maximum in the electrostatic potential that is found in these and the previous calculations. Further results are in agreement at lower temperatures with solutions obtained from a fluid model and the identification of the correct boundary condition on normal flow velocity to be used in fluid models. |
| Databáze: | OpenAIRE |
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