Drift-Alfven wave turbulence induced particle and heat transport in I-mode pedestal plasmas

In this work, most of the weakly coherent mode (WCM) characteristics and the level of transport coefficients observed in I-mode pedestal plasmas of C-Mod are reproduced theoretically. The dispersion relation of drift-Alfv & eacute;n wave (DAW) is analytically solved for both drift-wave (DW)and Alfv & eacute;n wave branches, and the WCM is identified to be the DW branch. The frequency ofDW branch in the laboratory frame is about 200 kHz, the poloidal phase velocity propagating inthe direction of electron diamagnetic drift is around7.0 km<middle dot>s(-1), and the relative magnitude ofnormalized fluctuations of electron temperature, density and magnetic field are| Te/Te0|/| n(e/)n(0)| approximate to 0.1and| b|/| n(e/)n(0)| approximate to 8.3x10(-4), respectively, which are all consistent with the characteristics ofWCM observed in C-Mod experiment. Moreover, the modulation-induced transport coefficientsin the presence of DAW turbulence are calculated. It is found that the electromagnetic part oftransport coefficient is about 10% of the electrostatic part. The particle diffusivity is0.21m(2)<middle dot>s(-1), which is about twice of the experimental value. Meanwhile, the electron thermalconductivity is0.27m(2)<middle dot>s(-1), and is in very good agreement with the correspondingexperimental and simulation values. These results may advance the understanding of theunderlying physics of turbulence and transport in the I-mode pedestal plasmas.