Compact toroid injection experiment in JFT-2M

Abstract

Compact toroid (CT) injection experiments with H mode plasmas were carried out for the first time in the JFT-2M tokamak. The soft X ray emission profile shows deep CT penetration into the core region of H mode plasmas heated by 1.2 MW NBI as well as in OH plasmas, with a toroidal magnetic field of 0.8 T. The line averaged electron density rapidly increased by Δe ≈ 0.2 × 1019 m-3 at a rate of 4 × 1021 m-3·s-1 in H mode and the fuelling efficiency was roughly 20%. An asymmetric radial profile in the soft X ray emission was produced for ∼50 μs by deep penetration of the CT.