UC San Diego

The interactions between ion temperature gradient-driven drift waves (DITG) and electron temperature gradient (ETG) turbulence were studied using simple models for the individual instability dynamics. A generalized k-space diffusion tensor was derived to represent the random shearing action of the DITG turbulence. The shearing due to short-wavelength DITG modes was shown to have a significant impact on large-scale ETG structures. The results indicate that DITG-induced fluctuation effect is significant when the amplitude of the gradient modulation is comparable to the equilibrium deviation from marginality.