Effects of temperature gradients on the toroidicity induced drift mode

Summary Form only given, as follows. Stability analysis has been carried out for the toroidicity-induced drift mode in tokamaks with T/sub i/=T/sub e/ (thus eta i= eta /sub e/), (k perpendicular to rho )/sup 2/<<1 (hydrodynamic ion response). In the core region of the tokamak discharge, the temperature gradients tend to stabilize the drift mode over the entire range of (k/sub 0/ rho )/sup 2/<0.1. The critical temperature gradients tend to stabilize the critical temperature gradient for stability is eta >or=2. However, in the outer region long-wavelength modes, (k/sub 0/r)/sup 2/=0.01 is further destabilized by the temperature gradient. When the ion temperature gradient is artificially suppressed, the electron temperature gradient alone is always stabilizing. Electron kinetic effects on the hydrodynamic ion temperature gradient mode ( eta mode) have also been examined. It has been found that the nonresonant electron contribution is strongly stabilizing, thus confirming an earlier conclusion that the eta /sub i/ mode is unlikely to exist in tokamaks.<>