Dynamic effects in plasma wakefield excitation

We have used 2D cylindrically symmetric particle-in-cell simulations to investigate the dynamics of a high energy electron beam propagating through an underdense plasma. The simulation parameters are relevant to a recent plasma wakefield experiment conducted at the Stanford Linear Accelerator Center [R. Assmann et al., Stanford Linear Accelerator Center Proposal, 1997]. We model the dynamic development of the beam and wakefield excitation over meters of propagation length. To most clearly illustrate the dynamics of both the beam and the wakefield, a video of the simulation data is presented. The main observation is that the beam dynamics, i.e., its betatron motion in the resulting ion channel, agree well with the theoretical predictions while the plasma wake remains almost invariant over the entire propagation distance. The video illustrates subtle details regarding the interplay between the beam dynamics and wakefield generation. The results presented here complement results published separately [S. Lee et al., Phys. Rev. E 61, 7014 (2000)].