Transient beam-head dynamics and start-up stability require analysis

Develop a transient start-up analysis for the head of a relativistic electron beam propagating through underdense space plasma, quantifying the onset and mitigation of hose instability during electron expulsion and transition to the ion-focused regime, and establishing methods for initial beam capture and guidance to the receiver.

Background

Initiating the beam involves expelling background plasma electrons to form the ion-focused channel. During this transition from background to steady state, the beam is susceptible to hose instability, and the pointing and capture problem is compounded by start-up transients.

The authors suggest that a positively biased receiver might assist in drawing in the initial pulses to establish the channel, but emphasize that a full transient analysis of the beam-head behavior is still required to ensure stable start-up and guidance.