Kinetic modes in a hot magnetized and weakly collisional plasma

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