Speaker
Description
The advent of high-peak-power laser technology [1] has enabled compact charged-particle acceleration with a higher acceleration gradient than conventional RF accelerators. One of the most promising schemes is laser wakefield acceleration of electrons [2], and significant progress has been made in achieving 10 GeV energy [3], a few-fs pulse duration [4], a transverse emittance of <1 mm-mrad [5], etc. However, these record values are not simultaneously achieved (or measured), and the parameter stability is not comparable to that of state-of-the-art linear accelerators.
Recently, we developed two schemes that improve both quality and stability. With these schemes, we demonstrated a high-quality electron beam with an energy of 376±16 MeV, a relative energy spread of 1.5±0.5%, a charge of 25.3±7.4 pC, a divergence of 0.5 mrad, and a pointing stability of 0.41ｘ0.23 $\mu$rad (error bars show standard deviations over multiple shots). With the improved quality, free-electron lasing around 20-50 nm was observed using a 2-m-long undulator with the undulator parameter of $K$=0.4-1.4 [6].
These stable electron beams further improved the system; more recently, we have removed some thermal effects, and electron-beam stability has improved [7].
In addition, we discuss the perspective of LWFA for higher electron energy and more stable electron-beam generation.
Acknowledgement
This work was supported by JST-Mirai Program Grant Number JPMJMI17A1, Japan.
References
[1] D. Strickland and G. Mourou, Opt. Commun. 56, 219 (1985).
[2] T. Tajima and J. M. Dawson, Phys. Rev. Lett. 43, 267 (1979).
[3] C. Aniculaesei et al., Matter Radiat. Extremes 9, 014001 (2024); E. Rockafellow et al., Phys. Plasmas 32, 053102 (2025).
[4] O. Lundh et al., Nat. Phys. 7, 219 (2011).
[5] S. K. Barber et al., Phys. Rev. Lett. 119,104801 (2017).
[6] Z. Jin, M. Kando et al., Phys. Rev. Res. 8, 013207 (2026).
[7] Z. Jin et al., Phys. Rev. Res. (submitted).