Limiter of plasma confinement means using pyrolytic graphite

Object: To restrict temperature elevation of the surface of a limiter in an ultra-high temperature plasma confinement means, while increasing the allowable level of plasma contamination by using pyrolytic graphite. Structure: This limiter is constructed by stacking a plurality of plate-like pieces made of pyrolytic graphite into a bricklike arrangement. The limiter surface of the pyrolytic graphite is constituted by the aligned surfaces of the individual plate-like pieces extending in the direction of low thermal conductivity. A support means for supporting the limiter is provided and protected by a cover made of graphite. When the limiter receives a high heat load from plasma, it dissipates heat by making use of high thermal conductivity portions parallel to the stacking surface, thereby preventing a rise in surface temperature. Since a limiter made of pyrolytic graphite is utilized, the allowable level of plasma contamination is increased to about 50 times that of a molybdenum limiter. (Seki, T.)