INITIAL BORONIZATION OF JT-60U TOKAMAK USING DECABORANE

A decaborane-based boronization system has been installed in the JT-60 U tokamak in order to reduce the influx of impurities during plasma di scharges. Boronization has been performed under a glow discharge using a helium-decaborane gas mixture. The properties of the boron films de posited through boronization and the effects of boronization on the to kamak discharges were investigated. It was found that the deposition o f a boron layer with high purity was achieved with few impurities othe r than hydrogen through boronization, and that the present boronizatio n deposited toroidally nonuniform boron film. It was also found that t he decaborane-based boronization resulted in good plasma performance s imilar to that of conventional boronization.