Characterization of electron beams from laser wakefield accelerations using external injection for soft x-ray free-electron lasers

Abstract

Laser plasma wakefield accelerations (LWFA) are the most promising candidates for future compact accelerators and also can be used for next-generation free-electron lasers (FELs). However, due to the insufficient electron beam quality, such as a few percent of energy spread, stability, and reproducibility, the electron beam from the LWFA has difficulty to be directly used for FELs with a range from soft X-ray to hard X-ray. To overcome this limitation of the beam quality from the laser wakefield acceleration using various injection techniques, one of the most reliable way is to use the electron beam with short duration, lower energy spread, and emittance from the RF photocathode. This external injection technique is planning with conventional S-band RF photocathode gun and final energy of 70 MeV, few tens fs duration, and lower emittance at Pohang Accelerator Laboratory Injector Test Facility (PAL-ITF). In this presentation, we show a simulation result on the characterization of the electron beam from LWFA using external injection for soft X-ray free-electron lasers.