Recent Progress in Plasma Control Studies on the Improvement of Plasma Performance in Heliotron J

• Published in: Plasma science & technology Vol. 13; no. 1; pp. 21 - 25
• Main Authors: Mizuuchi, Tohru, Nagasaki, Kazunobu, Okada, Hiroyuki, Kobayashi, Shinji, Yamamoto, Satoshi, Minami, Takashi, Ohshima, Shinsuke, Takeuchi, Masaki, Mukai, Kiyofumi, Lee, Hyunyong, Zang, Linge, Nomura, Kohta, Suwa, Masashige, Yamamoto, Kento, Yashiro, Hiroaki, Yoshino, Hayao, Arai, Shouhei, Kagawa, Tasuku, Minami, Takayuki, Mizuno, Kouji, Wada, Yoshinobu, Watada, Hiroto, Nishino, Nobuhiro, Nakashima, Yosuke, Hanatani, Kiyoshi, Nakamura, Yuji, Konoshima, Shigeru, Sano, Fumimichi
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.02.2011
• Subjects: 回旋共振频率; 性能改进; 电子回旋波; 离子温度; 等离子体密度; 资助计划; 超声分子束注入; 进展控制
• ISSN: 1009-0630
• DOI: 10.1088/1009-0630/13/1/05

Recent progress in plasma control studies on the improvement of plasma performance in Heliotron J is reviewed. The supersonic molecular beam injection （SMBI） fueling is successfully applied to Heliotron J plasma. A supersonic H2-beam is effectively injected to increase fueling efficiency and generate a peaked density profile. Local fueling with a short-pulsed SMBI can increase the core plasma density and avoid the degradation arising from edge cooling. Second harmonic electron cyclotron current drive （ECCD） experiments were conducted by launching a focused Gaussian beam with a parallel refractive index of -0.05 ≤ Nil 〈 0.6. Results show that the electron cyclotron （EC） driven current is determined not only by Nil but also by local magnetic field （B） structure where the EC power is deposited. Detailed analysis of the observed NI and B dependences is in progress with a ray-tracing simulation using the TRAVIS code. Fast ion velocity distribution was investigated using fast protons generated by ion cyclotron resonant frequency （ICRF） minority heating. For the standard configuration in Heliotron J, charge ex- change neutral particle analysis （CX-NPA） measurements show higher effective temperature of fast minority protons in the on-axis resonance case compared to that in the HFS （high field side） off-axis resonance case. However, the increase in bulk ion temperature in the HFS resonance case is larger than that in the on-axis resonance.