Description:
<jats:p>It is shown that, during the burst of the high frequency twisting mode induced by energetic ions, significant reconnected flux can be transiently generated due to toroidal coupling with tearing-parity mode. This forced reconnection is accompanied by a sudden jump of the local plasma rotation frequency, induced by electromagnetic torque, which tends to “lock” the twisting mode to the tearing mode at the coupled rational surface. Results are applied to interpret early experiments on the DIII-D tokamak [Luxon et al., Plasma Physics and Controlled Nuclear Fusion Research, 1986 (International Atomic Energy Agency, Vienna, 1987), Vol. 1, p. 159], where sawtooth inversion has been observed during high frequency (f∼100 kHz), intermediate mode number (m∼10) bursting activity [Heidbrink et al., Nucl. Fusion 31, 1635 (1991)].</jats:p>