Shear-flow-driven ion cyclotron instabilities of magnetic field-aligned flow of inhomogeneous plasma

The effect of magnetic field-aligned flow with a transverse flow velocity gradient (velocity shear) on the generation of electrostatic ion cyclotron waves is studied analytically by using kinetic formalism. It is shown that flow shear not only modifies the frequency and growth rate of a known current-driven electrostatic ion cyclotron instability (CDEIC), but is the source of the development of specific kinetic and hydrodynamic shear-flow-driven ion cyclotron instabilities at the levels of current along the ambient magnetic field, which is subcritical for the development of the CDEIC instability. (c) 2006 American Institute of Physics.