Flat bubble regime and laminar plasma flow in a plasma wakefield accelerator

Abstract

A simple 2D model of the bubble formation in a plasma wakefield accelerator is developed and investigated. We show that in the case of a flat driver, the bubble may consist of two parts. The first part corresponds to a laminar flow where plasma electron streams do not cross and the second to the two-stream (turbulent) flow. The laminar flow turns out to be robust to the symmetry breaking. Building off of the developed model, we demonstrate that, in the case of the laminar flow and nonrelativistic plasma electrons, the transverse wakefield is absent inside the bubble even in the case of a transversely nonuniform plasma.