Gyrokinetic simulation of electron turbulence spectrum

Kawai, Chika; Idomura, Yasuhiro   ; Maeyama, Shinya*; Ogawa, Yuichi*

To investigate relations between self-organization and flow structure formation in magnetized plasmas, energy spectrum structures of electron turbulence are estimated by gyrokinetic simulations. It is found that the existence of zonal flow formation is affected by the plasma density and the temperature ratio between ions and electrons, which change wave dispersion induced by diamagnetic rotation. Depending on saturation amplitudes of turbulence, zonal flow formation processes are varied from an inverse energy cascade due to self-organization to a modulational instability due to direct mode coupling. These results suggest that structures of electron turbulence are significantly changed by macroscopic plasma parameters.