15-CENTIMETER-DIAMETER UHV TRANSFER SYSTEM FOR REMOTE PLASMA-WALL INTERACTION EXPERIMENTS

A versatile UHV apparatus is described which permits large (up to 10 multiplied by 10 cm) sample arrays or entire experiments to be inserted from air into an operating tokamak. This can be done without perturbing the tokamak vacuum. Samples or experiments may be exposed in the tokamak for studies of plasma-wall interactions and removed at any time without requiring tokamak shutdown. Samples or experiments may be accurately positioned in the region between the vacuum wall and the plasma limiter remotely. The apparatus provides up to 20 electrical connections for thermocouples, heaters, and signal leads. It also provides linear and rotary mechanical motion for operating experiments synchronized to tokamak discharges.