An anisotropic character of nonlinear fluxes not involved in the plasma energy transport in the Hasegawa-Wakatani model

초록

Fluxes of both the vorticity and the plasma density due to the nonlinear E x B convective derivatives are divided into two parts. One part, which is almost isotropic, is well known to engage in the transfer of energies from the energy-producing scale where the phase mismatch between the density and the electric potential is large. The other part, in the Fourier space , is found to be highly anisotropic. If it is summed over k (y) , the result is nearly random around zero in k (x) while the sum over k (x) is approximately proportional to k (y) . In Fourier space, such anisotropic fluxes are found to be closely related to the gradients of the squares of the vorticity and the electric potential, respectively. We argue that the advecting velocities in Fourier space may be predicted on dimensional grounds.

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