Advanced Real-Time Feedback Control in JT-60U High Performance Discharges for Application to Fusion Reactor Plasmas

Journal Article · Sun Sep 15 00:00:00 EDT 2002 · Fusion Science and Technology

OSTI ID:20845857

Fukuda, T; Oikawa, T; Takeji, S; Isayama, A; Kawano, Y; Neyatani, Y; Nagashima, A; Nishitani, T; Konoshima, S; Tamai, H; Fujita, T; Sakamoto, Y; Kamada, Y; Ide, S; Koide, Y; Takenaga, H; Kurihara, K; Sakata, S; Ozeki, T; Kawamata, Y ; Miura, Y M ^[1]

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1. Japan Atomic Energy Research Institute (Japan)

The significance of real-time feedback control is emphasized in this paper as an indispensable method to improve and sustain the improved plasma characteristics in JT-60U high fusion performance discharges as well as to operate the fusion reactor under the optimal divertor conditions with respect to the heat load and exhaust pumping. In accordance, substantial improvement in the equivalent fusion amplification gain of over unity has been reproducibly achieved at the JT-60U tokamak in the reversed shear mode of operation with the robust feedback controls, where the value of target density was deliberately optimized for the reliable internal transport barrier formation, and the magneto-hydrodynamic stability control was performed with the stored energy feedback. The feedback control techniques also demonstrated the effectiveness to produce quasi-steady-state high-performance plasmas. In addition, three major parameters associated with the fusion reactor instrumentations, namely the neutron production rate, operating density, and divertor radiation power, were simultaneously feedback controlled in the ELMy H-mode plasmas. Here, the matrix response function was evaluated to identify the limitations involved with the linear combination of independent controls. Other advanced feedback schemes, such as the feedback suppression of the neoclassical tearing mode required to sustain high plasma pressure in a steady-state, are also described. Finally, the controversial issues for the future intelligent plasma control necessary for the advanced steady-stated tokamak reactor are addressed.

• OSTI ID: 20845857
• Journal Information: Fusion Science and Technology, Vol. 42, Issue 2,3; Other Information: Copyright (c) 2006 American Nuclear Society (ANS), United States, All rights reserved. http://epubs.ans.org/; Country of input: International Atomic Energy Agency (IAEA); ISSN 1536-1055
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CONTROL
DIVERTORS
EDGE LOCALIZED MODES
FEEDBACK
GAIN
H-MODE PLASMA CONFINEMENT
HEATING LOAD
JT-60U TOKAMAK
MAGNETOHYDRODYNAMICS
NEOCLASSICAL TRANSPORT THEORY
NEUTRONS
OPERATION
PERFORMANCE
PLASMA
PLASMA DENSITY
PLASMA PRESSURE
RESPONSE FUNCTIONS
REVERSED SHEAR
STEADY-STATE CONDITIONS
STORED ENERGY
TEARING INSTABILITY
THERMONUCLEAR REACTORS