Stimulated L-H transition with SMBI in the HL-2A tokamak

ORAL

Abstract

In the HL-2A plasmas, the transition from low confinement mode (L-mode) to high confinement mode (H-mode) externally stimulated by supersonic molecular beam injection (SMBI) has been observed. SMBI, a fuelling tool with higher fuelling efficiency than that of gas puffing, can abruptly increases the electron density and its gradient. Then it helps to build the pedestal with steep gradient. It was found that more intense SMBI induces large turbulence intensity. Interesting, the intensity of geodesic acoustic mode (GAM) was enhanced by SMBI, then the turbulence intensity was clamped. When the plasma transited into the H-mode, the GAM disappeared. The enhanced GAM can also transits into another oscillating shear flow, limit cycle oscillation (LCO). The interplay between oscillating flows and turbulence was studied. The result suggests that the oscillating flows can be enhanced or triggered by SMBI and those flows initiate the L-H transition. Further, they play a important role in the continuous increase of the mean shear flow prior to the transition.

Authors

  • Wulv Zhong

    • Southwestern Institute of Physics, PO Box 432, Chengdu 610041, China
    • Southwestern Institute of Physics

  • Xiaolan Zou

    • CEA, IRFM, F-13108 Saint-Paul-lez-Durance, France

  • Aushu Liang

    • Southwestern Institute of Physics, PO Box 432, Chengdu 610041, China

  • Xuru Duan

    • Southwestern Institute of Physics, PO Box 432, Chengdu 610041, China

  • Min XU

    • Southwestern Institute of Physics, PO Box 432, Chengdu 610041, China

  • Beibin Feng

    • Southwestern Institute of Physics, PO Box 432, Chengdu 610041, China

  • Chengyuan Chen

    • Southwestern Institute of Physics, PO Box 432, Chengdu 610041, China

  • Guoliang Xiao

    • Southwestern Institute of Physics, PO Box 432, Chengdu 610041, China

  • Zhongbing Shi

    • Southwestern Institute of Physics, PO Box 432, Chengdu 610041, China

  • Zengchen Yang

    • Southwestern Institute of Physics, PO Box 432, Chengdu 610041, China

  • Min Jiang

    • Southwestern Institute of Physics, PO Box 432, Chengdu 610041, China

  • Peiwan Shi

    • Southwestern Institute of Physics, PO Box 432, Chengdu 610041, China

  • Jie Wen

    • Southwestern Institute of Physics, PO Box 432, Chengdu 610041, China

  • Xianming Song

    • Southwestern Institute of Physics, PO Box 432, Chengdu 610041, China

  • Deliang Yu

    • Southwestern Institute of Physics, PO Box 432, Chengdu 610041, China

  • Linge Zang

    • Southwestern Institute of Physics, PO Box 432, Chengdu 610041, China

  • Longwen Yan

    • Southwestern Institute of Physics, PO Box 432, Chengdu 610041, China

  • Jiaqi Dong

    • Southwestern Institute of Physics, PO Box 432, Chengdu 610041, China

  • Xuantong Ding

    • Southwestern Institute of Physics, PO Box 432, Chengdu 610041, China

  • Yong Liu

    • Southwestern Institute of Physics, PO Box 432, Chengdu 610041, China