A diocotron instability is a plasma instability created by two sheets of charge slipping past each other. Energy is dissipated in the form of two surface waves propagating in opposite directions, with one flowing over the other. This instability is the plasma analog of the Kelvin-Helmholtz instability instability in Fluid Mechanics.
References
W. Knauer, "Diocotron Instability in Plasmas and Gas Discharges", Journal of Applied Physics, Vol. 37, Issue 2, page 602-611.
