摘要
1 Introduction Internal kink mode driven by the supra-thermal electrons is reported on DⅢ-D tokamak. This instability is most active when electron cyclotron current drive （ECCD） is applied on the high field side of the flux surface. It has a bursting behavior with poloidal/toroidal mode number=n/n=1/1. In positive magnetic shear plasma this mode becomes fishbone instability. The mode frequency is about 10 kHz. Strong m=1 MHD activities are also observed in HL-IM tokamak during off-axis electron cyclotron resonance heating （ECRH） when the cyclotron location is placed just outside the q= 1 flux surface at high field side .
