Comparison of particle confinement in the high confinement mode plasmas with the edge localized mode of the Japan Atomic Energy Research Institute Tokamak-60 Upgrade and the DIII-D tokamak

Particle confinement was compared for the high confinement mode plasmas wit h the edge localized mode in the Japan Atomic Energy Research Institute Tok amak-60 Upgrade (JT-60U) [S. Ishida, JT-60 Team, Nucl. Fusion 39, 1211 (199 9)] and the DIII-D tokamak [J. L. Luxon , Plasma Physics and Controlled Nuc lear Fusion Research 1986 (International Atomic Energy Agency, Vienna, 1987 ), Vol. 1, p. 159] considering separate confinement times for particles sup plied by neutral beam injection (NBI) (center fueling) and by recycling and gas-puffing (edge fueling). Similar dependence on the NBI power was obtain ed in JT-60U and DIII-D. The particle confinement time for center fueling i n DIII-D was smaller by a factor of 4 in the low density discharges and by a factor of 1.8 in the high density discharges than JT-60U scaling, respect ively, suggesting the stronger dependence on the density in DIII-D. The par ticle confinement time for edge fueling in DIII-D was comparable with JT-60 U scaling in the low density discharges. However, it decreased to a much sm aller value in the high density discharges. (C) 2001 American Institute of Physics.