Generation and optimization of high quality multi-GeV electron beams using an evolving electron driver in the nonlinear blowout regime

Plasma-based acceleration (PBA) is promising approach for generating high quality ultrarelativistic beams to drive next-gen x-ray light sources and particle collider experiments. Over the years, research has largely focused on injection methods that use a density down ramp or field ionization to generate high quality beams. Recently, we proposed a new method of controllable injection that relies on focusing an electron drive beam in a nonlinear plasma wakefield [1]. Using the approach, injection was demonstrated in two different regimes using OSIRIS particle-in-cell (PIC) simulations. In this talk, we present a predictive model to characterize injection triggered by an electron drive beam that is self-focused by the plasma column. The model is used to describe how the wake evolution and final injected beam parameters scale with the drive bunch parameters. Parameter scans from PIC simulations for different drivers are shown and compared with the model predictions. PIC simulations indicate that injection and optimal beam loading can be achieved until the drive beam fully pump depletes. Based on the simulation results, the injected beam can be efficiently accelerated to 18.27 GeV with a projected energy spread of 0.5% and peak normalized brightness of 10^20 A/m^2/rad^2.



[1] T. N. Dalichaouch et al., Phys. Rev. Accel. Beams 23, 021304 (2020).