A quasi-linear theory of dissipative ion-acoustic instability

Abstract

The authors consider the instability of an electron beam in a plasma with a hot electron component. The presence of the beam means that waves with negative energy may be propagated through the plasma. If the pair collision frequency or the collisionless Landau damping decrement is greater than the beam growth rate, a dissipative instability is created in the plasma/cold beam system.They indicate the conditions under which the dissipative ion-acoustic instability originates, together with its growth rate and threshold excitation current. On the basis of quasi-linear theory equations, they derive the noise level created by development of the instability and also the distribution of the energy lost by the beam in terms of degrees of freedom (increase in the effective beam temperature and heat-up of electrons and plasma ions).