Kinetic modes in a hot magnetized and weakly collisional plasma

Velocity space perturbations associated with low-frequency waves launched i n a weakly collisional plasma are shown to consist of a discrete spectrum o f modes. Collisions are modeled using an energy and momentum conserving one -dimensional Fokker-Planck operator. The linearized Vlasov-Poisson-Fokker-P lanck system of equations is solved by expanding the perturbed ion-distribu tion function in terms of Hermite polynomials, from which an eigenvalue pro blem is set up. The eigenvalues and eigenvectors yield the ion acoustic mod e that is weakly damped [J. Dougherty, Physics of Fluids 7, 1788 (1964)], a s well as a discrete spectrum of kinetic modes. (C) 1999 American Institute of Physics. [S1070-664X(99)00806-X].