Influence of elastic collisions on neutral gas transport in boundary plasmas
An analytical solution to the one-dimensional linear kinetic transport equation (slab model) is presented and applied to investigations of the influence of elastic collisions between neutral atoms and plasma ions on neutral gas transport under typical tokamak boundary conditions. By comparing solutions obtained for neutral helium and neutral hydrogen, the possibility of local helium enrichment in divertors or pump limiters is considered in detail. This paper reinvestigates the inverted pump limiter concept of Prinja and Conn, however with applications to the issue of helium removal in general, such as by divertors. By using a general Monte Carlo algorithm to solve the same kinetic equations, the analytical solutions are verified. Furthermore some of the simplifying approximations, which were necessary to obtain closed form analytical solutions, are then removed in the Monte Carlo solution. This allows a critical assessment of such approximations.
Bibliographic Reference: Report: IPP 8/1 EN (1992) 26 pp.
Availability: Available from Max-Planck-Institut für Plasmaphysik, 8046 Garching bei München (DE)
Record Number: 199211271 / Last updated on: 1994-11-29
Original language: en
Available languages: en