Open AccessSuppression of MHD modes with active phase-control of probe-injected currents
Author(s) -
J. W. Brooks,
J. Bialek,
Chris Hansen,
J.P. Levesque,
M. E. Mauel,
G.A. Navratil,
A. Saperstein,
I. G. Stewart
Publication year - 2021
Publication title -
nuclear fusion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.774
H-Index - 120
eISSN - 1741-4326
pISSN - 0029-5515
DOI - 10.1088/1741-4326/ac1544
Subject(s) - tokamak , physics , magnetohydrodynamic drive , magnetohydrodynamics , resistive touchscreen , wavelength , current (fluid) , electromagnetic coil , plasma , atomic physics , optics , engineering , quantum mechanics , electrical engineering , thermodynamics
Active phase-control of probe-injected current is shown to both suppress and amplify long-wavelength rotating magnetohydrodynamic instabilities in the HBT-EP tokamak. Four probes are connected in quadrature and energized to drive non-axisymmetric currents through the edge of the tokamak, creating magnetic perturbations comparable to previously-studied saturated kink modes or resonant magnetic perturbations that are generated by an external control coil array. Measurements of the magnetic perturbations from the probe-injected currents determine a set of current-carrying helical filaments used to model active feedback control of resistive wall modes. These experiments suggest current-injection feedback may be an effective alternative to external control coils for control of RWMs and other long-wavelength kink-like modes at the edge of tokamaks.