IMPROVED CONFINEMENT WITH REVERSED MAGNETIC SHEAR IN TFTR

A new tokamak confinement regime has been observed on the Tokamak Fusion Test Reactor (TFTR) where particle and ion thermal diffusivities drop precipitously by a factor of similar to 40 to the neoclassical level for the particles and to much less than the neoclassical value for the ions in the region with reversed shear. This enhanced reversed shear confinement mode allows the central electron density to rise from 0.45 x 10(20) m(-3) to similar to 1.2 X 10(20) m(-3) with T-i similar to 24 keV and T-e similar to 8 keV. This regime holds promise for significantly improved tokamak performance.