Ion acoustic waves in the plasma with the power-law q-distribution in nonextensive statistics

We investigate the dispersion relation and Landau damping of ion acoustic waves in the collisionless magnetic-field-free plasma when the plasma is described by the nonextensive q-distributions of Tsallis statistics. We show that the increased numbers of superthermal particles and low velocity particles can explain the strengthened and weakened modes of Landau damping, respectively, with the q-distribution. When the ion temperature is equal to the electron temperature, the weakly damped waves are found to be the distributions with small values of q. (C) 2008 Elsevier B.V. All rights reserved.