title: Plasma-wakefield acceleration of a positron beam.
abstract: Plasma-wakefield excitation by positron beams is examined in a regime for which the plasma dynamics are highly nonlinear. Three dimensional particle-in-cell simulations and physical models are presented. In the nonlinear wake regime known as the blowout regime for electrons, positron wakes exhibit an analogous "suck-in" behavior. Although analogous, the two wakefield cases are quite different in terms of their amplitudes, wavelengths, waveforms, transverse profiles, and plasma density dependence. In a homogenous plasma, nonlinear positron wakes are smaller than those of the corresponding electron case. However, hollow channels are shown to enhance the amplitude of the positron wakes.
authors.affiliation: University of Southern California, Los Angeles, California 90089, USA.
authors.forename: S
authors.initials: S
authors.lastname: Lee
authors.forename: T
authors.initials: T
authors.lastname: Katsouleas
authors.forename: R G
authors.initials: RG
authors.lastname: Hemker
authors.forename: E S
authors.initials: ES
authors.lastname: Dodd
authors.forename: W B
authors.initials: WB
authors.lastname: Mori