18th IAEA Fusion Energy Conference

High-Radiation and High-Density Experiments in JT-60U

H. Kubo, S. Sakurai, N. Asakura, S. Konoshima, H. Tamai, S. Higashijima, A. Sakasai, H. Takenaga, K. Itami, K. Shimizu, T. Fujita, Y. Kamada, Y. Koide, H. Shirai, T. Sugie, T. Nakano, N. Oyama, H. Urano¹⁾, T. Ishijima²⁾, K. W. Hill³⁾, D. R. Ernst³⁾, A. W. Leonard⁴⁾, the JT-60 Team
Japan Atomic Energy Research Institute, Naka Fusion Research Establishment, Naka-machi, Naka-gun, Ibaraki-ken, 311-0193, Japan
1) Graduate School of Engineering, Hokkaido University, Sapporo, 060-8628, Japan
2) Graduate School of Engineering, Nagoya University, Nagoya, 464-8603, Japan
3) Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, NJ 08543, USA
4) General Atomics, P. O. Box 85608, San Diego, CA, 92186-5608, USA

Abstract.
In order to obtain confinement improved plasmas with high radiation at high density, Ar gas was injected into ELMy H-mode plasmas in JT-60U. A confinement improvement of HH98 (y,2) ~ 1 was obtained with a high radiation loss power fraction (~ 80 %) at an electron density of ~ 0.65 nGW. The HH-factor was about 50% higher than that in plasmas without Ar injection.