Progress on Ultra-relativistic Electron Acceleration from Laser Wakefield Acceleration

Abstract

Laser wakefield acceleration (LWFA) has emerged as a revolutionary approach for developing compact particle accelerators by exploiting ultra-intense femtosecond laser pulses to drive plasma waves that sustain electric fields exceeding 100 GV/m. LWFA experiments have rapidly advanced from proofof-concept demonstrations to the generation of multi-GeV, quasi-monoenergetic electron beams. Progress in controlled electron injection, plasma-density tailoring, and guiding techniques has enabled stable, high-charge, low-emittance beams suitable for many applications. LWFA also plays a key role in the development of compact radiation sources. Betatron radiation is directly produced during LWFA, and when combined with undulators, a compact free-electron laser can be realized. LWFA-driven electron beams can also be used to produce X- and γ-rays via bremsstrahlung or Compton scattering. Since the electron beam produced by LWFA is naturally synchronized with the driving laser pulse, it provides a unique platform for exploring strong-field quantum electrodynamics. This review summarizes recent advances in LWFA physics, key performance metrics such as energy, charge, divergence, emittance, and efficiency, and emerging applications in ultrafast imaging, radiotherapy, and fundamental QED studies. The continuing integration of petawatt-class lasers, precise plasma-wave control, and machine-learningbased optimization is expected to drive a new generation of compact, high-performance accelerators and radiation for applications.