The Behavior of Neutral Particles in NOVA-II Plasma

Abstract

We have investigated the behavior of neutral particles in a hydrogen plasma with a small tokamak NOVA-II by means of the H_α line intensity measurement. Our particular attention was paid to the contribution of the limiter to the recycling and the equilibrium balance of plasma particles. The H_α line intensity at the limiter was three times as strong as those at other positions. Transport of the neutrals injected by gas puffing in the toroidal direction was also investigated. No direct contribution of injected neutrals to the density distribution of neutral was observed at the position ±90° away from the gas injection valve in the toroidal direction.