S. Cirant et al., MEASUREMENT AND CONTROL OF THE GROWTH OF ROTATING MAGNETIC ISLANDS BYELECTRON-CYCLOTRON CURRENT DRIVE IN A TOKAMAK, Fusion technology, 31(3), 1997, pp. 338-349
The design of a feedback system based on the application of electron c
yclotron (EC) current drive in high-density tokamak plasmas is present
ed. A realistic evaluation is given of the current drive produced by h
igh-power gyrotron tubes for EC-wave beams injected from the low field
side in the O-mode polarization. The driven current, calculated using
a relativistic analytical formalism along the ray trajectories, is in
serted in a consistent theory of nonlinear tearing-mode evolution. Res
ults of modeling calculations are presented, showing the possibility o
f controlling by means of a digital system the evolution of the width
of rotating magnetic perturbations by phase-locked modulation of the g
yrotron power source.