Observation of Resistive Wall Modes in JT-60U

• Published in: Journal of Plasma and Fusion Research Vol. 78; no. 5; pp. 447 - 454
• Main Authors: TAKEJI, Satoru, TOKUDA, Shinji, KURITA, Genichi, SUZUKI, Takahiro, ISAYAMA, Akihiko, TAKECHI, Manabu, OYAMA, Naoyuki, FUJITA, Takaaki, IDE, Shunsuke, ISHIDA, Shinichi, KAMADA, Yutaka, OIKAWA, Toshihiro, SAKAMOTO, Yoshiteru, TUDA, Takashi, Team, the JT-60
• Format: Journal Article
• Language: English
• Published: Nagoya The Japan Society of Plasma Science and Nuclear Fusion Research 2002; Japan Society of Plasma Science and Nuclear Fusion Research
• Subjects: current-driven kink; ideal magnetohydrodynamics; JT-60U; low n kink; pressure-driven kink; resistive wall mode; reversed shear; thermal quench; tokamak
• ISSN: 0918-7928
• DOI: 10.1585/jspf.78.447

Resistive wall modes (RWM) associated with ideal magnetohydrodynamic current-driven (βN < 0.2) and pressure-driven (βN > 2.4) kink modes with low toroidal mode number n (n = 1) have been identified in JT-60U. The pressure-driven RWM occurs at the plasma toroidal rotation of about 1% the Alfvén speed without clear continuous slowing down of the plasma toroidal rotation. Occurrence of n = 1 RWMs result in thermal quench accompanied by higher n (n ≥ 2) modes. In the case of current-driven (˜ zero β) RWMs, a thermal quench occurs only at the peripheral region just after the RWM. In contrast, a thermal quench occurs in the whole plasma region following a drastic increase in the growth rate of the RWM from the order of τw-1 (τw is the resistive diffusion time of the wall) to larger than 102 τw-1in the case of pressure-driven (high β) RWMs.