Modulation of proton beams by relativistic electron beam-plasma instability

Abstract

Two-dimensional electromagnetic particle-in-cell simulations are performed to investigate the transport of relativistic electron beams co-moved with a proton beam in background plasmas. For the beam with the radius much larger than the plasma skin depth, the current filamentation instability excited by the relativistic electron beam can be clearly observed and the transverse magnetic fields in the plasma increase significantly. The proton beam is modulated strongly by the electromagnetic fields in plasmas, and a netlike structure in the beam profile is formed with a high density contrast, which can be provided as an effective tool to diagnose the instability. The dynamic effects of plasma ions are shown to be important and play a significant role in the dynamic evolution of the proton beam.