Oblique electromagnetic instabilities for an ultra relativistic electron beam passing through a plasmaA. Bret
ETSI Industriales, Universidad de Castilla-La Mancha - 13071 Ciudad Real, Spain
received 10 March 2006; accepted in final form 13 April 2006
published online 10 May 2006
We present an investigation of the electromagnetic instabilities which are triggered when an ultra relativistic electron beam passes through a plasma. The linear growth rate is computed for every direction of propagation of the unstable modes, and temperatures are modelled using simple waterbag distribution functions. The ultra relativistic unstable spectrum is located around a very narrow band centered on a critical angle whose value is given analytically. The growth rate of modes propagating in this direction decreases like k-1/3.
52.35.Qz - Microinstabilities (ion-acoustic, two-stream, loss-cone, beam-plasma, drift, ion- or electron-cyclotron, etc.).
52.40.Mj - Particle beam interactions in plasmas.
52.35.Hr - Electromagnetic waves (e.g., electron-cyclotron, Whistler, Bernstein, upper hybrid, lower hybrid).
© EDP Sciences 2006