Two-stream instability analysis for propagating charged particle beams with a velocity tilt

The linear growth and saturation of the two-stream instability for a charged particle beam that is longitudinally compressing as it propagates through a background plasma (due to an applied velocity tilt) has recently been examined. Detailed, 1D particle-in-cell simulations are carried out to examine the growth and saturation of a wavepacket produced by a small amplitude density perturbation in the background plasma. The resultant electrostatic wave spectra that evolves due to the coupling of the primary (resonant) unstable wave packet with the plasma is examined.