Analysis of eta(i) mode by reactive and dissipative descriptions and the effects of magnetic q and negative shear on the transport

Ion temperature gradient driven modes are studied in the short wavelength region by using a three pole reactive fluid model and an adiabatic E x B convection model, as well as the gyro-Landau fluid model. In all of the above models the parallel ion dynamics is included and the results have been compared both analytically and numerically. Furthermore, the effects of the magnetic safety factor q on the growth rate and transport coefficient chi(i) have been investigated. The maximum of chi(i) as a function of the mode number is computed, and the stabilizing effect of the negative magnetic shear has been studied.