Contributions of nonlinear fluxes to the temporal response of fluid plasma

Abstract

Nonlinear energy fluxes are known to redistribute energy according to detailed conservation laws. In addition, the temporal response of plasma is altered by the linear reaction due to the nonlinear fluxes that are not involved in the transport of the energy. Simulations for three cases of the adiabaticity parameter , 1.0 and 10.0 are performed in relation to the Hasegawa–Wakatani model and the frequency alterations are found to be notable for where k is the Fourier scale and is the ion gyro-radius computed at the electron temperature. The levels of the density fluctuation and the potential get closer to each other as α increases and they are equal for . Yet, the frequencies are still discernible for . Non-transporting fluxes (NTFs) turned out to be anisotropic because the phase difference between and has symmetry so that is isotropic in the Fourier space while is odd in ky. The NTF of the energy is approximated to be proportional to the gradient of the energy in the y direction of the Fourier space with the proportionality coefficient being dimensionally advecting velocity.