Plasma waves driven by non-neutral fireball beams with applications to positron acceleration

Plasma-based positron acceleration is a long-standing challenge to the advanced accelerators community in the pathway to a compact electron-positron collider. Some of the most prominent solutions rely on hollow laser beams [1] or electrons beams [2] as drivers of the wakefield structure.

One concept that has recently drawn attention in the context of plasma micro-instabilities is the fireball beam [3], which consists of spatial overlap between an electron and a positron beam. This work shows that standard Gaussian, non-neutral fireball beams in certain conditions evolve self-consistently to a hollow shape electron beam with the positron beam focused on-axis, thus enabling conditions for stable positron acceleration studied in [1,2].

We use theory and particle-in-cell simulations to demonstrate stable positron acceleration with the scheme, perform a systematic tolerances study, and study the analogous system with a laser replacing the electron beam.

[1] J.Vieira et al., Physical Review Letters 112, 215001 (2014)

[2] N.Jain et al., Physical Review Letters 115, 215001 (2015)

[3] N Shukla et al., New Journal of Physics 22, 013030 (2020)