XFELs driven by LWFA-based e-beams are promising for generating high-brilliance X-ray lasers on a laboratory scale, and they are anticipated to enable significant applications. However, realizing FEL gain still a significant challenge, primarily due to the stringent requirements on beam quality, especially the energy spread and emittance, both on global and slice aspect. Here we introduce several strategies to optimise these parameters of e-beam within a down-ramp injection scheme in LWFA.
 

LWFA,XFEL