Modeulated toroidal current suppression of MHD activity on the HT-7 superconducting tokamak

摘要

Modulation of the plasma current has been used successfully to suppress MHD activity. This was achieved in discharges near the density limit where large MHD m=2 tearing modes were Suppressed by sufficiently large plasma current oscillations. The modulation of the plasma current must Be large enough to move the resonance q=2 surface outside the island width on a timescale faster Than the growth time of the instability. These observations resemble those predicted in a previous Study of non - linear effects on the m = 1 mode.