Plugging regime in the pump limiter throat

The plugging regime in which there is no outstreaming neutral flux is studied for a closed configuration pump limiter (with a throat). The plugging length and the neutral density buildup at the neutralizer plate are derived by computations. The analytical expressions are supported by numerical evidence. Owing to the throat effect, an improved pump limiter ‘efficiency’ is found. This effect is mainly due to neutral-side wall interactions.