Design, Construction and Testing of a Model Fast Shutter for the ITER Negative Ion Injectors

A Fast Shutter system for the ITER Negative Ion Injectors has been designed. The system incorporates an external primary pneumatic drive system with translation of motion across the vacuum boundary being achieved via a magnetic coupling. Sealing of the Fast Shutter in the closed position is achieved by utilisation of a metallic race track seal whose design characteristics incorporate the properties of high deflection with low linear load. The design has been conceived along modular lines in order to minimise installation and maintenance problems. A one quarter scale model of the Fast Shutter system has been constructed and tested. To date 55,000 cycles have been completed with a maximum conductance across the seal of 0.93 l/s (Deuterium equivalent).