Turbulence & Instability

[HEDS4-02(Invited)] Spontaneous Plasma Confinement Transition in Magnetically Confined Fusion Plasmas

*Tatsuya Kobayashi^1,2,3 (1. National Institute for Fusion Science, National Institutes of Natural Sciences, 2. The Graduate University for Advanced Studies, SOKENDAI, 3. Research Institute for Applied Mechanics, Kyushu University)

A long-standing mystery, low-to-high confinement transition was clarified by a detailed measurement of the radial electric field (Er) and turbulence. Across the transition, an edge localized Er structure was spontaneously excited that leaded to transport reduction. The radial charge separation due to different trajectories of ions and electrons was found to play a role for the Er excitation.