Improved confinement with reversed magnetic shear in TFTR

Abstract

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 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 × 1020 m-3 to 1.2 × 1020 m-3 with Ti24 keV and Te8 keV. This regime holds promise for significantly improved tokamak performance. © 1995 The American Physical Society.