Figure 2: Simulation of the longitudinal field.
From: Demonstration of a positron beam-driven hollow channel plasma wakefield accelerator
The Ez field due to an ultrarelativistic positron beam driving a wake in a hollow channel plasma, as simulated by QuickPIC34,35. The beam propagates to the left and the 1σ contour of the beam is shown by the white dashed line. The black dotted lines at ±240 and ±290 μm are the inner and outer radii of the plasma channel, respectively. Lineouts of the simulated and calculated on-axis Ez field at r=0 μm and the radial variation in Ez at the peak decelerating field at z=11 μm are shown with solid and dashed black lines, respectively. The simulated and calculated fields show excellent agreement up to z=80 μm, where the charge separation of the plasma electrons on the surface of the channel becomes significant.
