SCALING OF CONFINEMENT WITH MAJOR AND MINOR RADIUS IN THE TOKAMAK FUSION TEST REACTOR

Plasma-size scans have been performed in the Tokamak Fusion Test Reactor to investigate the effect of major and minor radius upon energy confinement in high-recycling plasmas heated by neutral-beam injection. The major radius, minor radius, and aspect ratio were varied over a large range (a = 0.4-0.9 m, R = 2.08-3.2 m, R/a = 2.8-8.0). The energy confinement measured with diamagnetic and kinetic diagnostics scales strongly with major radius, and weakly or negatively with minor radius.