SWITCHING CONTROL DEVICE FOR CONTROLLING FLOW RATE OF CESIUM GAS FROM CESIUM OVEN DEVICE FOR NEGATIVE ION SOURCE IN NEUTRON INCIDENCE DEVICE OF FUSION DEVICE

摘要

PROBLEM TO BE SOLVED: To prevent temperature from becoming nonuniform easily and to prevent a cold spot from being formed easily by using a bimetal shutter valve that performs self switching operation according to the temperature of a device itself without using any active drive force.;SOLUTION: For example, a cesium oven device that is used for a neutron incidence device for additional heating of the plasma of a tokamak-type nuclear fusion device is provided with a bimetal shutter valve for controlling the flow rate of a cesium gas. The bimetal shutter valve is provided with, for example, a fan-shaped opening 16 and is provided with a shutter where one end of a coil-shaped strip bimetal 10 is welded, and the other end of the bimetal 10 is welded to an inner cylinder flange 11. Then, when temperature increases, the curvature of the bimetal 10 increases and hence a shutter 9 rotates and is fully open, for example, at 230°C or higher. For fully closing it on emergency or the like, a nitrogen gas is allowed to flow to an air-cooling pipe 7 for cooling and the bimetal shutter valve itself is cooled to, for example, 180°C or less.;COPYRIGHT: (C)2000,JPO