VELOCITY SHEAR-INDUCED EFFECTS ON ELECTROSTATIC ION PERTURBATIONS

Linear evolution of electrostatic perturbations in an unmagnetized ele ctron-ion plasma shear flow is studied. New physical effects, arising due to the non-normality of linear dynamics are disclosed. A new class of nonperiodic collective mode with vortical motion of ions, characte rized by intense energy exchange with the mean flow, is found. It is a lso shown that the velocity shear induces extraction of the mean how e nergy by ion-sound waves and that during the shear-induced evolution t he ion-sound waves turn eventually into ion plasma oscillations. (C) 1 997 American Institute of Physics.