Anomalous transport in tokamak by drift waves

Abstract

The recent laser and microwave scattering measurement of density fluctuations in tokamaks show the existence of broad band large amplitude fluctuations in the frequency range of the drift waves. Therefore the drift wave model is used to interpret the anomalous electron and ion thermal flux from tokamak. The anomalous energy flux is obtained from vlasov equation averaged over phase without classical collision. The distribution function is expanded in powers of electric field and perturbed distribution function is obtained to third order. For the electrons, taking only the first order distribution function, the anomalous heat flux is obtained. For the ions, the wave-particle resonance is possible in the third order, thus the anomalous heat flux is obtained taking the third order perturbed distribution. Compared with the recent experimental data for the ion and electron heat flux, it is found that driftwave model can explain the anomalous transport to some degree.