Ion temperature drift instabilities in a sheared magnetic field

Results from the first particle code simulations of the ion-temperature-gradient-driven instabilities in a sheared slab geometry are reported. In the linear stage of the instability, the results are in very good agreement with the theoretical calculations of the mode frequency, growth rate, and radial mode structure. Ion energy transport caused by the instability is found to be the process primarily responsible for nonlinear saturation. Enhanced fluctuations associated with marginally stable eigenmodes have been observed.