Gyrokinetic simulation of microinstabilities in high temperature tokamaks

A new numerical approach to investigate the stability of low-frequency fluctuations in high temperature tokamaks is developed by solving the gyrokinetic equations for the ion and electron directly as an initial value problem. The advantage of this approach is the inclusion of many important kinetic features of the problem without approximations. The ion-temperature- gradient mode is investigated as an example of this new simulation technique. Both the adiabatic electron model and the full drift-kinetic electron model are studied. Numerical results show that the full drift-kinetic electron model is more unstable.