Abstract： The dispersion relation of the lower hybrid wave in the tokamak current drive regime (ω > 2ωLH, where ωLH is the lower hybrid frequency) is analysed. Toroidicity effects can shift the parallel refractive index upward or downward. The downward shift will lead to a mode conversion from the slow wave to the fast wave. It is indicated that this is the main mechanism limiting the effectiveness of tokamak lower hybrid current drive. Accordingly, a sufficient condition is obtained for the wave penetration, corresponding to a critical density, which is proportional to f4/3B2/3(A)4/3, with f being the wave frequency, B the magnetic field strength and A the aspect ratio. Quantitative agreement with experiments is found.
SHI Bing-Ren. Analytic Study of Density Limit Mechanism for Tokamak Lower
Hybrid Current Drive Experiments[J]. 中国物理快报, 2001, 18(2): 251-253.
SHI Bing-Ren. Analytic Study of Density Limit Mechanism for Tokamak Lower
Hybrid Current Drive Experiments. Chin. Phys. Lett., 2001, 18(2): 251-253.
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.
2001, Vol. 18 
