Electrostatic ion-temperature-gradient modes and anomalous transports in acollision-dominated plasma

By employing a two fluid model, a set of equations for ion pressure gradien t driven low-frequency (in comparison with the ion-gyrofrequency) electrost atic waves in a collisional magnetoplasma has been derived. The equations e xhibit a coupling between the electrostatic potential, the parallel ion vel ocity and ion-temperature perturbations. In the linear limit, a new dispers ion relation has been derived and analyzed numerically to demonstrate the e xistence of ion-temperature-gradient driven drift-dissipative modes. Since in a highly collisional plasma there is a departure from the Boltzmann elec tron response, there appears anomalous particle and ion-energy transports d ue to nonthermal fluctuations. Taking some typical tokamak parameters, the transport coefficients are numerically depicted for maximally growing drift wave fluctuations. The results of our investigation are useful for the und erstanding of fluctuation driven transports in tokamak edges in which colli sions are dominant.