Impurity transport in temperature gradient driven turbulence

Impurity transport driven by ion temperature gradient turbulence in tokamak plasmas

Impurity transport driven by electrostatic turbulence is analyzed in weaklycollisional tokamak plasmas using a semi-analytical model based on a boundary-layer solution of the gyrokinetic equation. Analytical expressions for the perturbed density responses are derived and used to determine the stability boundaries and the quasilinear particle fluxes. For moderate impurity charge number Z, the st...

Electron temperature gradient driven turbulence*

Collisionless electron-temperature-gradient-driven ~ETG! turbulence in toroidal geometry is studied via nonlinear numerical simulations. To this aim, two massively parallel, fully gyrokinetic Vlasov codes are used, both including electromagnetic effects. Somewhat surprisingly, and unlike in the analogous case of ion-temperature-gradient-driven ~ITG! turbulence, we find that the turbulent electr...

Impurity Transport in Plasma Edge Turbulence

where θ is the density of impurities, μθ the collisional diffusivity, and ζ = mθ qθ e mi ρs Ln the influence of inertia, which enters via the polarization drift. The latter makes the flow compressible, consequently for ideal (massless) impurities, ζ = 0 and advection is due to the incompressible electric drift only. In all cases the impurity density is assumed to be so low compared to the bulk ...

Impurity Transport in 3D Plasma Edge Turbulence

with τe being the electron collision time. nEQ is an equilibrium density associated with neoclassical fields and currents. K (nEQ) =−∇qJPS, which in turn is driven by the corresponding neoclassical potential JPS = 1 C (φPS). The contribution of impurities to the gross plasma density ni,0 is assumed to be negligible, i. e. ni = ni,0+nimp ≈ ni,0. For cold impurities the ion-drift velocity is give...

Ion temperature gradient driven turbulence with strong trapped ion resonance