A formalism is developed for optimizing the design of feedback coils placed around a tokamak plasma in order to control the resistive shell mode. It is found that feedback schemes for controlling the resistive shell mode fail whenever the distortion of the mode structure by the currents circulating in the feedback coils becomes too strong, in which case the mode escapes through the gaps between the coils, or through the centers of the coils. The main aim of the optimization process is to reduce this distortion by minimizing the coupling of different Fourier harmonics due to the feedback currents. It is possible to define a quantity which parametrizes the strength of the coupling. Feedback fails for The optimization procedure consists of minimizing subject to practical constraints. If there are very many evenly spaced feedback coils surrounding the plasma in the poloidal direction then the optimization can be performed analytically. Otherwise, the optimization must be performed numerically. The optimal configuration is to have many, large, overlapping coils in the poloidal direction.
Skip Nav Destination
Article navigation
June 1998
Research Article|
June 01 1998
Optimal design of feedback coils for the control of external modes in tokamaks
R. Fitzpatrick;
R. Fitzpatrick
Institute for Fusion Studies, Department of Physics, The University of Texas at Austin, Austin, Texas 78712
Search for other works by this author on:
E. P. Yu
E. P. Yu
Institute for Fusion Studies, Department of Physics, The University of Texas at Austin, Austin, Texas 78712
Search for other works by this author on:
Phys. Plasmas 5, 2340–2354 (1998)
Article history
Received:
October 27 1997
Accepted:
March 04 1998
Citation
R. Fitzpatrick, E. P. Yu; Optimal design of feedback coils for the control of external modes in tokamaks. Phys. Plasmas 1 June 1998; 5 (6): 2340–2354. https://doi.org/10.1063/1.872908
Download citation file:
Sign in
Don't already have an account? Register
Sign In
You could not be signed in. Please check your credentials and make sure you have an active account and try again.
Pay-Per-View Access
$40.00
Citing articles via
ICF target optimization using generative AI
M. Ben Tayeb, V. Tikhonchuk, et al.
The long road to ignition: An eyewitness account
Mordecai D. Rosen
Progress toward fusion energy breakeven and gain as measured against the Lawson criterion
Samuel E. Wurzel, Scott C. Hsu
Related Content
Toward a compact levitated superconducting dipole for positron-electron plasma confinement
AIP Conference Proceedings (January 2018)
Two-dimensional calculation of eddy currents on external conducting walls induced by low- n external modes
Phys. Plasmas (March 1998)
H-infinity controller design for efficiency optimization of magnetic bearings in a flywheel energy storage system
AIP Conference Proceedings (November 2022)
Equations for studies of feedback stabilization
Phys. Plasmas (September 1998)
Characterization of force factor on voice coil actuator for active vibration isolation system
AIP Conference Proceedings (July 2021)