Current Profile Control for High Bootstrap Current Operation in ITER

• Published in: Plasma and Fusion Research Vol. 7; p. 2403124
• Main Authors: MANO, Junji, YAMAZAKI, Kozo, OISHI, Tetsutarou, ARIMOTO, Hideki, SHOJI, Tatsuo
• Format: Journal Article
• Language: English
• Published: The Japan Society of Plasma Science and Nuclear Fusion Research 2012
• Subjects: bootstrap current; current-diffusive ballooning mode; external current; steady state; TOTAL code
• ISSN: 1880-6821; 1880-6821
• DOI: 10.1585/pfr.7.2403124

For the achievement of steady-state fusion power plant, non-inductively current-driven plasma operation should be maintained in tokamak fusion reactors. Total non-inductive current is a summation of bootstrap current proportional to the plasma pressure gradient and externally driven non-inductive current such as neutral beam driven current. Especially in order to establish a commercial reactor, it is necessary to reduce the amount of external current-drive power and to maintain the majority of the plasma current with bootstrap current. Burning plasma has high autonomy, so the change in current density profile including changes in particle and heat transports should be checked. In this study time-evolution analysis of the current density profile for burning plasmas in the ITER machine has been conducted by using 2.0-dimensional equilibrium, 1.5-dimensional-transport code (TOTAL code). Here current-diffusive ballooning mode model was adopted as a heat transport model. It is concluded that external current-drive is required both in the center and near the periphery of the plasma in order to maintain steady-state profiles of temperature and density with high bootstrap current fraction.