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Merging formation and current amplification of field‐reversed configuration
Author(s) -
Inomoto Michiaki,
Ono Yasushi
Publication year - 2007
Publication title -
ieej transactions on electrical and electronic engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.254
H-Index - 30
eISSN - 1931-4981
pISSN - 1931-4973
DOI - 10.1002/tee.20183
Subject(s) - field reversed configuration , toroid , reversed field pinch , tokamak , physics , pinch , magnetic field , current (fluid) , joule heating , diamagnetism , atomic physics , spheromak , plasma , kink instability , magnetohydrodynamics , electromagnetic coil , nuclear magnetic resonance , magnetic confinement fusion , thermodynamics , nuclear physics , quantum mechanics
The merging formation of the field‐reversed configuration (FRC) has been developed in the TS‐3 merging experiment, leading us to a new scenario of FRC slow formation, heating and current amplification. Two force‐free spheromaks with opposing toroidal fields were merged together in the axial direction to form a high‐β FRC with higher efficiency than the conventional field‐reversed theta‐pinch method. This unique relaxation from the force‐free (β ∼ 0.05 − 0.1) spheromaks to the high‐β (β ∼ 0.7 − 1) FRC is attributed to the conversion of toroidal magnetic energy into ion thermal energy through the reconnection outflow. A central ohmic heating (OH) coil worked successfully to amplify the FRC plasma current by a factor of 2. Toroidal mode analysis of magnetic structure indicated that the tilting stability of the oblate FRC was provided by an ion kinetic effect. This oblate FRC is also useful as an initial equilibrium to produce a high‐β p spherical tokamak (ST) with diamagnetic toroidal magnetic field, suggesting the close relationship between FRCs and high‐β p STs in the second stable region of the ballooning mode. © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.