Ad. Rogava et al., SHEAR LANGMUIR VORTEX - AN ELEMENTARY MODE OF PLASMA COLLECTIVE BEHAVIOR, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics, 57(6), 1998, pp. 7103-7110
Linear evolution of electrostatic perturbations in a cold, unmagnetize
d, two-component plasma with shear flow is studied. It is shown that t
he velocity shear induces, due to the non-normality of the linear dyna
mics, a new elementary mode of plasma nonperiodic collective behavior-
the ''shear Langmuir vortex.'' The mode, characterized by intense ener
gy exchange with the mean flow, is associated with nonoscillatory moti
on of the plasma species. In the low-shear limit, the vortex patterns
can be described by extremely simple analytic solutions both for the t
wo-dimensional and three-dimensional cases. It is shown that the two-d
imensional vortices are able to extract the mean flow energy only tran
siently, while the three-dimensional structures can grow asymptoticall
y. In moderate and high shear regimes, the conversion of shear Langmui
r vortexes into Langmuir oscillations becomes possible; the latter has
nonresonant character and happens abruptly in time.