S. Ohdachi, K. Y. Watanabe, S. Sakakibara, H. Yamada, Y. Narushima,, H. Funaba, Y. Suzuki, K. Toi, I. Yamada, T. Minami, K. Narihara, K. Tanaka, T. Tokuzawa, K. Kawahata, A. Komori and the LHD Experimental Group
Two approaches to the reactoré–relevant high-beta plasmas with profile control in the Large Helical Device
Date of publication:
21 IAEA Fusion Energy Conference, EX/8-1Rb
From detailed optimization of configuration, volume averaged <beta>~5% has been achieved in the Large Helical Device(LHD). While the heating efficiency was the main point to be optimized in this approach, to form a more peaked pressure profile is another promising approach towards the high beta regime. A higher electron density profile with a steeper pressure gradient has been formed by pellet injection. From the MHD stability analysis, this peaked pressure profile is stable against the ideal MHD modes. By both approaches, the central plasma beta_0 reaches about 10%.