Electron Plasma Waves in a Two-Temperature Plasma

Dispersion relations of electron waves of small amplitude in a plasma of two-temperature electrons are studied theoretically. Addition of small amount of hot electrons to the plasma increases the damping of electron plasma wave. For the temperature ratio of six, when the density of hot electrons exceeds about four percents, the wave separates into two modes. One is the plasma wave of cool electrons when \(\omega{\gtrsim}\omega_{\text{p}}\) and merges in one of higher-order modes when ω<ω p . The other mode which is cut off at ω=ω p also merges in higher-order modes when ω≫ω p . The non-dispersive mode when ω<ω p has much larger damping rate than the similar mode in the plasma of Maxwellian and water-bag electrons.