Self-stabilizing positron acceleration in a plasma column*

Stable acceleration of high-quality positron beams in a plasma-based accelerator is a highly-challenging task, but necessary to realize a plasma-based linear collider. Recently, we proposed a plasma-based positron acceleration scheme in which a wake suitable for efficient, high-quality positron acceleration is produced in a plasma column by means of an electron drive beam [1,2]. 

Here we analyze the performance of the scheme from the point of view of stability when offsets and/or tilts of the driver and witness beams with respect to the plasma column symmetry axis are present. By means of particle-in-cell simulations, we show that propagation of both beams is inherently stable. Finally, we provide tolerances that allow for stable positron acceleration while retaining feasible beam quality.

[1] S. Diederichs, et al. "Positron transport and acceleration in beam-driven plasma wakefield accelerators using plasma columns." Physical Review Accelerators and Beams 22.8 (2019): 081301.

[2] S. Diederichs, et al. "High-quality positron acceleration in beam-driven plasma accelerators." Physical Review Accelerators and Beams 23.12 (2020): 121301.