Numerical study of generating high-quality electron beam in laser wakefield acceleration using plasma density bump

We have demonstrated the tunable electron beams into the laser-driven wakefield1 using a suitable plasma density bump to generate good quality sub-femtosecond electron bunches. The controlled electron injection is reported at a well-defined space and time is reported using quasi-3D particle-in-cell simulations2. An intense Terawatt short laser pulse propagates through the plasma with a localized density bump region. The phase velocity of the wakefield is varied by density modulation, which controls the electron injection3. A comprehensive set of simulations showed the generation of about sub-pico-Coulomb, sub-femtosecond electron bunches with average energy up to 500 MeV. The electron beam reported can be crucial in the generation of the desirable electron beam for FEL drivers.


[1] E. Esarey, C. B. Schroeder, and W. P. Leemans, “Physics of laser-driven plasma-based electron accelerators,” Rev. Mod. Phys.81, 1229–1285 (2009).

[2] R. Lehe, M. Kirchen, I. A. Andriyash, B. B. Godfrey, and J. L. Vay, Computer Physics Communications203, 66–82 (2016).

[3] M. P. Tooley, B. Ersfeld, S. R. Yoffe, A. Noble, E. Brunetti, Z. M. Sheng, M. R. Islam, and D. A. Jaroszynski, “Towards attosecond high-energy electron bunches: Controlling self-injection in laser-wakefield accelerators through plasma-density modulation,” Phys. Rev. Lett.119, 044801 (2017).