Modelling of a plasma-accelerator-driven free-electron laser

Plasma-accelerator-driven linear accelerators can significantly reduce the footprint of future free-electron lasers, unlocking various applications in research and industry. The characteristic ultra-short femtosecond-level duration of plasma-accelerated electron bunches and the intrinsic coupling of bunch charge, peak current and energy spread constitutes a unique FEL operation mode demanding thorough optimisation and tolerance studies. Here, we model the FEL process of a plasma-accelerator-driven electron bunch to pinpoint the necessary optimisation of the 6D beam brightness and tolerances for competitive overall performance.