Dr. Ishida also reported success in simplifying the method used for startup and current drive in tokamaks. Recently in JT-60U, startup and current drive was achieved using a combination of radiofrequency power and neutral beam injection, as opposed to the more traditional use of central solenoid (CS) coils. Up to ninety percent of the total plasma current (so-called bootstrap current) was driven this way, creating a plasma with high energy confinement comparable to that previously obtained only with central solenoid coils. Ishida said, "The demonstration of CS-less tokamak operation suggests the substantial simplification and the associated size reduction and increase in fusion power density of tokamak devices leading to the economical fusion power plant." These latter results were obtained via a collaboration among JAERI, University of Tokyo, Kyoto University, Kyushu University and Kyushu Tokai University.

Further information is at http://www-jt60.naka.jaeri.go.jp