GEOMETRY EFFECTS ON PARTICLE REMOVAL WITH THE PUMP LIMITER ALT-I
In the course of the ALTI pump limiter experiments on TEXTOR, limiter heads of different shapes, exhaust channels and materials have been applied and their performance has been compared. Particle removal rates up to 10 Torr 1/s have been observed in the case of TiC surfaces. Values with the graphite head at the same radial position are typically a factor of 23 lower. The removal rate for a "detached plasma" discharge is 3050% reduced as compared to a normal one. The removal efficiency reaches values in excess of 50%. The results suggest a guiding rule for the design of pump limiters with high removal efficiency: The effective pumping speed at the neutralizer plate should be large compared to the conductance for neutral particles backstreaming from the neutralizer plate to the main plasma.
Bibliographic Reference: JOURNAL OF NUCLEAR MATERIALS, NOS. 145-147 (1987), PP. 825-829
Record Number: 1989126004500 / Last updated on: 1988-02-01
Available languages: en