ABSTRACT
A magnetized inhomogeneous plasma can sustain a particular low frequency electrostatic wave type called “drift-waves” because they propagate in the direction of the electron diamagnetic drift. The driving mechanism is the pressure gradient perpendicular to the externally imposed magnetic Àeld. The plasma can reach an energetically favorable state by smoothing out the gradients in pressure, and there is thus free energy available for driving the waves linearly unstable. Alternatively, though more formally, it can be argued that the source of free energy is the gradient drift current associated with the pressure gradient.
