调制托卡马克等离子体电流对H模式行为和径向电场的影响(英文)

H-Mode Behavior and Radial Electric Field Induced by Modulated Plasma Current in Tokamak

HT—6M托卡马克装置边界湍流加热时观察到了欧姆相约束的改进,实验中,从低约束模式(L模)向高约束模式(H模)突然转换时的径向电场E_r的特性和空间结构进行了研究,实验发现,更负的径向电场E_r是在电流脉冲后0.2 ms形成的.同时形成了输运垒.输运垒的特征为:电子温度和电子密度分布的陡化,极向旋转速度和环向旋转速度增加的区域正好位于E_r位井中,径向电场E_r位井从最外层闭合磁面(LCFS)向内移动.E_r位井的位置和深度是与所感应的脉冲电流与欧姆电流的比值有关.在一次放电过程中,L-H转换被多个电流脉冲反复触发.

The improved Ohmic confinement phase (like H-mode) has been observed during the edge multi-pulse turbulent heating (EMTH) in the HT—6M Tokamak. The feature and spatial structure of the radial electric field E_r, suddenly formed at the L-H transition, have been investigated in the present experiment. It is discovered that the formation of the more negative Er well occurs with in 0.2 ms time scale after the current pulse. The transport barrier was formed during EMTH. This transport barrier, including the steep gradient regions of density, temperature and the region of the increasing poloidal rotation v_θ and toroidal rotation v_ψ, lies in the E_r well, and the E_r well was moved inward from the last closed flux surface (LCFS) . The positions and the depths of the E_r well are depended on the ratio of induced pulse current with plasma Ohmic current. The L-H transition are triggered repeatedly by multi-current pulses in one discharge process.