ABSTRACT
A plasma is known to exhibit instabilities if it is spatially nonuniform or inhomogeneous. The plasma in a spatially nonuniform state, retaining a higher free energy, tries to release it by modulating itself to form an energy release channel much more rapidly than the otherwise collisional process. The plasma in space and astrophysical settings has been increasingly found to have naturally a quite nonuniform structure, such as a bundle of filaments or a sponge-like structure. The properties of these instabilities vary, of course, depending upon the nature of the plasma nonuniformity and other conditions, and the properties of ensuing turbulence driven by these instabilities vary as well. The drift wave instability has a double personality, kinetic and fluid-like. It is driven by the presence of a density gradient across the magnetic field that permeates the plasma. Nonuniformities and inhomogeneities of other types in a plasma lead to other types of plasma instabilities and often to a turbulent plasma.
