Vacuum exhaust device for thermonuclear devices

Purpose: To enhance the economy by improving the utility rate without disposing hydrogen isotope of fuel. Constitution: Gas produced by thermonuclear reaction is introduced from a vacuum vessel to a trap, and steam contained in the gas is condensed and removed in the vessel. Thereafter, hydrogen isotope is mainly condensed by a cryogenic condensation pump, and helium is adsorbed by a cryogenic adsorption pump. A partition valve is closed in this state, a gate valve is opened, but when vacuum exhaust operation is not executed, the valve is opened, and the gate valve is closed, thereby isolating the condensation pump and the adsorption pump and revovering separately the hydrogen isotope and the helium stored so far. Accordingly, the hydrogen isotope is not disposed with the helium, bue can be reutilized. (Yoshihara, H.)