The influence of RF current on the tearing mode in multi-harmonic theory

The tearing mode dispersion relation is calculated in the J-TEXT tokamak by the method of Fitzpatrick’s multi-harmonic Rutherford theory and the two-harmonic code. Calculations for two-harmonic approximation indicate that when the radio-frequency (RF) current is more concentrated at the O-point, whether radially or angularly, it tends to excite the second harmonic. The second harmonic component of the RF-current excitation is more beneficial for the stabilization of the tearing mode.