Abstract: Lower-hybrid current drive (LHCD) experiments were carried out in the HL-1M hydrogen plasmas. The suppression of sawtooth instabilities by LHCD has been observed in the sawtoothing discharges, an improvement in the global energy confinement time of up to 20% is observed. There is an optimal rf-power range for the complete suppression of the central MHD instabilities. Possible mechanisms for the stabilization of the sawtooth instability are discussed from the measurement of internal inductance and current profile reconstruction using an equilibrium code. A large long-lived snake-like oscillation is newly observed at the end of sawtooth-stabilization phase of the LHCD operation in the HL-1M tokamak. It is evident that such perturbation is due to a temperature depression caused by impurity accumulation during LHCD.
LIU Yi;QIU Xiao-Ming;DONG Yun-Bo;GUO Gan-Cheng;ZHONG Yun-Ze;FU Bing-Zhong;LIU Yong. Sawtooth-Stabilization and Snake-Excitation during LHCD on the HL-1M[J]. 中国物理快报, 2004, 21(2): 360-363.
LIU Yi, QIU Xiao-Ming, DONG Yun-Bo, GUO Gan-Cheng, ZHONG Yun-Ze, FU Bing-Zhong, LIU Yong. Sawtooth-Stabilization and Snake-Excitation during LHCD on the HL-1M. Chin. Phys. Lett., 2004, 21(2): 360-363.
YANG Qing-Wei;ZHOU Hang-Yu;FENG Bei-Bin;LIU Yi;PAN Yu-Dong;LI Wei;DUAN Xu-Ru;CHEN Wei;CUI Zheng-Ying;JI Xiao-Quan;DING Xuan-Tong;HL-A team. A New Criterion for Disruption Prediction on HL-2A[J]. 中国物理快报, 2006, 23(4): 891-894.