Quasilinear diffusion coefficients in a finite Larmor radius expansion for ion cyclotron heated plasmas

摘要

In this paper, a reduced model of quasilinear diffusion by a small Larmorradius approximation is derived to couple the Maxwell's equations and theFokker-Planck equation self-consistently for ion cyclotron range of frequencywaves in a tokamak. The reduced model ensures the important properties of thefull model by Kennel-Engelmann diffusion, such as diffusion directions, wavepolarizations, and H-theorem. The kinetic energy change (W-dot) is used toderive the reduced model diffusion coefficients for the fundamental damping andthe second harmonic damping to the lowest order of the finite Larmor radiusexpansion. The quasilinear diffusion coefficients are implemented in a coupledcode (TORIC-CQL3D) with the equivalent reduced model of dielectric tensor. Wealso present the simulations of the ITER minority heating scenario, in whichthe reduced model is verified within the allowable errors from the full modelresults.