Simulations of transverse dynamics in a laser-plasma accelerator

Abstract Laser wakefield accelerators offer a promising solution for producing highenergy electron beams in compact setups. Beyond obtaining the required energy, the applications require achieving precise transverse parameters of the accelerated beam. This study investigates the evolution of the emittance and Twiss parameters through the plasma stage, including the density plateau, upramp, and downramp and their connection to conventional transport lines. Particular attention is given to the matching conditions between the plasma and the transport line, with recommendations proposed to mitigate emittance growth. A new approach is used, based on tracking through a series of special quadrupoles simulating the plasma transverse focusing, with a computational speed-up of over four orders of magnitude compared to laser-plasma Particle-In-Cell simulations.