Extension of integrated high performance regimes with impurity and deuterium particle control in Japan Atomic Energy Research Institute Tokamak-60 Upgrade (JT-60U)

摘要

In JT-60U [Horiike , Fusion Eng. Des. 16, 285 (1991)] extension of high performance plasmas toward high density, high radiation-loss-power fraction and high fuel purity has been explored by pellet injection, Ar injection and study of impurity production. By pellet injection from the high-field-side, the density range for the high-poloidal-beta high-confinement mode plasmas with edge localized modes (high-beta(p) ELMy H-mode plasmas) has been extended to 70% of the Greenwald density (n(GW)). In ELMy H-mode plasmas with Ar injection, confinement time given by the International Thermonuclear Experimental Reactor ELMy H-mode scaling IPB98(y,2), electron density of 0.8 n(GW) and radiation-loss-power fraction of 0.8 have been achieved simultaneously. Type-I ELMs disappeared, and the heat flux to the divertor plates due to ELMs decreased by a factor of 10. At the carbon divertor plates, the chemical sputtering yields due to C2Hx/C2Dx (where x=2, 4, and 6) production in addition to CH4/CD4 production have been measured systematically. It was shown that the C2Hx/C2Dx production was dominant in the low temperature divertor plasmas. (C) 2002 American Institute of Physics. [References: 39]