Stationary turbulent spectra of toroidal eta(i) mode

Toroidal ion temperature gradient (ITG) driven drift mode turbulence has been analyzed analyti- cally and numerically. By using weak nonlinearity arguments and random phase approximation, dynamic and wave kinetic equations are derived. Three different nonlinearities, namely ExB, convective, and diamagnetic nonlinearities, play important roles in the turbulent spectral transfer. The power spectra of the weak ITG-mode turbulence are obtained analytically for \k\much greater than 1 and \k\<1 ranges in the wave number space. Foward energy cascading due to convective and diamagnetic nonlinearities will balance the inverse energy cascading due to ExB nonlinearity at \k\approximate to 1/p(s) (k is the wave number, p(s)=c(s)/omega(ci), where c(s) is the sound velocity and omega(ci) is the ion cyclotron frequency and results in energy condensation at \k\approximate to 1/p(s). (C) 1996 American Institute of Physics.