Sharp boundary analysis of electrostatic flute modes

A linear, electrostatic, stability analysis of a magnetized cross-field drifting plasma with a sharp boundary is presented. The analysis corrects an error in a previously published sharp boundary theory [Phys. Fluids 19, 882 (1976)] and extends another theory [Geophys. Res. Lett. 14, 60 (1987)] to include finite electron mass and non-neutral perturbations. The instability’s long wavelength structure is associated with the classical flute instability, while the peak of the growth rate curve, at much shorter wavelengths, is a Buneman-like instability.