a1 Plasma Physics Research Institute, Department of Physics, University of Natal, Durban, South Africa
We discuss critical curves that allow us to predict, qualitatively, the topological behaviour of higher-order modes in a two-electron-temperature plasma as wavenumber and hot electron fraction are varied. The relationship of these higher-order modes to the electron-acoustic wave is elucidated.
(Received May 18 1989)
(Revised January 29 1990)