Excitation of waves at 2 iωsubp,e/sub/i and back propagating waves at iωsubp,e/sub/i: a parametric study

摘要

We present a parametric study of electrostatic waves generated with angular frequencies 2 wp,e and - wp,e by an electron beam using a one-dimensional Vlasov code. We consider a background plasma consisting of three components: two electron populations (a background and a beam) and a proton population (with a mass ratio mp /me = 400 and temperatures Tp = Te = T ). We investigate the influence of different beam parameters on the nonlinear growth rate of waves with angular frequency 2wp,e and compare the results of the numerical experiments to theoretical predictions. We also examine the presence and excitation of back propagating waves with angular frequency wp,e. A discussion on the possible generating mechanisms of the different modes observed in these simulations is also presented.