托卡马克内部输运垒的判据-核工业西南物理研究院.pptVIP

托卡马克剪切流和内部输运垒触发机制初探 董家齐 龙永兴 牟宗泽 张锦华 核工业西南物理研究院 成都432信箱 托卡马克输运垒的特征 输运垒Internal Transport Barrier or External Transport Barrier （ITB或ETB）是先进托卡马克放电的特征； 托卡马克内部输运垒的定义 1）regions where the gradient length is reduced with respect to the L- and H-mode values: 托卡马克内部输运垒的定义 2) regions where 托卡马克内部输运垒的判据 =0.014 for JET discharges 托卡马克内部输运垒的形成条件 形成ITB或ETB的外部条件是非欧姆加热（即中性束或波）功率要高于一定的阈值； 这种阈值随非欧姆加热功率输入时等离子体的状态而变； 实验发现，ITB比较倾向于在低q的有理面附近形成； 实验发现，输运垒的形成与MHD不稳定性有密切的关系； 同时，理论和实验研究还发现，输运垒的形成总是伴随着剪切流； 托卡马克内部输运垒触发机制的现有理论 这些实验现象已经在世界各大装置上普遍观察到。但是，对剪切流和输运垒的触发机制，目前还没有比较统一的理论。 Coupling of external and internal MHD modes magnetic braking of plasma rotation at inner q surface; Fishbone instability: expulsion of fast resonant particle sheared plasma flow equivalent to a radial electric field; Double internal transport barrier triggering mechanismin tokamak plasmas ? 1, Introduction Non-monotonic q profiles are desirable for advanced tokamak (AT) operation with internal transport barriers (ITBs) Such configurations are prone to excitation of double tearing modes (DTMs) Possible causal relationship between DTMs and the experimentally observed Double ITBs around qmin surfaces is one important research topic in tokamak physics 2, Equilibrium and MHD equation We consider the standard sheared slab configuration, , (1) where equals zero at , The plasma sheet is of scale length a in x-direction, has a current in z-direction, The equilibrium flow velocity , The resistivity and the viscosity are both assumed to be constant Non-linear reduced MHD equations 1) Ohm’s la