Transport of poloidal momentum induced by ion cyclotron range of frequencies waves

Abstract

By using the Lie-transform method, transport of the poloidal momentum induced by the ion cyclotron range of frequencies waves is calculated in the slab geometry. The poloidal momentum equation is derived in the cases with the equilibrium distribution function adopted as a Maxwellian distribution and an anisotropic distribution in the velocity space; in both cases, the poloidal Reynolds stress (PRS) is due to the correlation between the deviation of particle position and the deviation of particle energy, and the poloidal momentum source term is due to the correlation between the deviation of particle poloidal velocity and the deviation of particle energy. The PRS can be partly canceled out by the poloidal momentum source term, resulting in an effective PRS, which is related to the symmetry of poloidal spectrum and the order of cyclotron resonance. In the basic frequency cyclotron resonance case, by adopting the long-wave-limit approximation, the effective PRS is related to the gradient of electric field energy; this term dominates in the case with a strong asymmetry of poloidal spectrum. The calculation is extended to the case with a spatially inhomogeneous equilibrium distribution. The contribution from the inhomogeneity in the configuration space to the effective PRS is derived, which is found to be comparable to the part driven by the inhomogeneity in the velocity space in the case with a symmetric poloidal spectrum.