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Asymmetric self-injection of electrons in a laser wakefield accelerator via localized laser redshifting

Zsolt Lécz1,2,*, Adam Hughes3,†, Ahmed Ali Jasim Ajam1,2, Jasmin Hills3, Louis Forrester3, Szilárd Majorosi1, Daniel Papp1, Tamás Lucza1, Kristóf Nacsa1 et al.

Kwinten Nelissen1, Miklos Kiss1, Mikhail Kalashnikov1, Levente Lehotai1, Viktor Pajer1, Nóra Csernus-Lukács1, János Bohus1, Roland S. Nagymihály1, Zulfikar Najmudin3, Christos Kamperidis1, and Nasr A. M. Hafz1,2

  • *Contact author: zsolt.lecz@eli-alps.hu
  • †Contact author: a.hughes19@imperial.ac.uk
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Phys. Rev. Research 8, 023080 – Published 27 April, 2026

DOI: https://doi.org/10.1103/q9m2-czfl

Abstract

Propagation of intense laser pulses in underdense plasma always involves nonlinear evolution of the laser envelope, which leads to large deviations from the initial Gaussian intensity profile. The modulations in the intensity envelope have strong influence not only on the formation of the wakefield, but also in the process of electron injection; thus, it defines the final spectral and angular distribution of the accelerated electrons. Better understanding of the laser pulse evolution is crucial for the correct interpretation of the experimental results, especially in the highly relativistic regime. We developed a simple numerical tool, which adequately models the evolution of the laser envelope up to the point when the spectral broadening becomes significant. Our numerical modeling sheds light on the asymmetric wakefield generation and consequent off-axis injection of electrons, observed in experiments and particle-in-cell simulations.

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References (26)

  1. T. Tajima and J. M. Dawson, Laser electron accelerator, Phys. Rev. Lett. 43, 267 (1979).
  2. H. Peng et al., Coherent subcycle optical shock from a superluminal plasma wake, Phys. Rev. Lett. 131, 145003 (2023).
  3. J. Y. Hua et al., Narrowband THz radiation from laser wakefields driven in uniform plasma via tight laser focusing, Plasma Phys. Control. Fusion 67, 102501 (2025).
  4. E. Esarey and M. Pilloff, Trapping and acceleration in nonlinear plasma waves, Phys. Plasmas 2, 1432 (1995).
  5. K. Schmid et al., Density-transition based electron injector for laser driven wakefield accelerators, Phys. Rev. ST Accel. Beams 13, 091301 (2010).
  6. K. K. Swanson et al., Control of tunable, monoenergetic laser-plasma-accelerated electron beams using a shock-induced density downramp injector, Phys. Rev. Accel. Beams 20, 051301 (2017).
  7. A. Pak, K. A. Marsh, S. F. Martins, W. Lu, W. B. Mori, and C. Joshi, Injection and trapping of tunnel-ionized electrons into laser-produced wakes, Phys. Rev. Lett. 104, 025003 (2010).
  8. M. Chen et al., Electron injection and trapping in a laser wakefield by field ionization to high-charge states of gases, J. Appl. Phys. 99, 056109 (2006).
  9. M. J. V. Streeter et al., Observation of laser power amplification in a self-injecting laser wakefield accelerator, Phys. Rev. Lett. 120, 254801 (2018).
  10. B. Lei et al., Shot-to-shot electron beam pointing instability in a nonlinear plasma bubble, Phys. Rev. E 109, 015204 (2024).
  11. J. Kim et al., Subfemtosecond wakefield injector and accelerator based on an undulating plasma bubble controlled by a laser phase, Phys. Rev. Lett. 127, 164801 (2021).
  12. Y. Ma et al., Generation of femtosecond gamma-ray bursts stimulated by laser-driven hosing evolution, Sci. Rep. 6, 30491 (2016).
  13. R. Rakowski et al., Transverse oscillating bubble enhanced laser-driven betatron X-ray radiation generation, Sci. Rep. 12, 10855 (2022).
  14. E. N. Nerush and I. Yu. Kostyukov, Carrier-envelope phase effects in plasma-based electron acceleration with few-cycle laser pulses, Phys. Rev. Lett. 103, 035001 (2009).
  15. X. L. Chen and R. N. Sudan, Two-dimensional self-focusing of short intense laser pulse in underdense plasma, Phys. Fluids B 5, 1336 (1993).
  16. P. Sprangle, C.-M. Tang, and E. Esarey, Relativistic self-focusing of short-pulse radiation beams in plasmas, IEEE Trans. Plasma Sci. 15, 145 (1987).
  17. B. A. Shadwick et al., Nonlinear laser energy depletion in laser-plasma accelerators, Phys. Plasmas 16, 056704 (2009).
  18. P. Sprangle et al., Stable laser-pulse propagation in plasma channels for GeV electron acceleration, Phys. Rev. Lett. 85, 5110 (2000).
  19. S. Shiraishi et al., Laser red shifting based characterization of wakefield excitation in a laser-plasma accelerator, Phys. Plasmas 20, 063103 (2013).
  20. W. Lu et al., Generating multi-GeV electron bunches using single stage laser wakefield acceleration in a 3D nonlinear regime, Phys. Rev. ST Accel. Beams 10, 061301 (2007).
  21. Zs. Lecz et al., Single-mode laser guiding in non-parabolic plasma channels for high-energy electron acceleration, Plasma Phys. Control. Fusion 67, 115015 (2025).
  22. R. S. Nagymihály, The petawatt laser of ELI ALPS: Reaching the 700 TW level at 10 Hz repetition rate, Opt. Express 31, 44160 (2023).
  23. K. Gao et al., Online plasma diagnostics of a laser-produced plasma, Plasma Sci. Technol. 19, 015506 (2017).
  24. R. Lehe et al., A spectral, quasi-cylindrical and dispersion-free particle-in-cell algorithm, Comput. Phys. Commun. 203, 66 (2016).
  25. Sz. Majorosi et al., High-order exponential solver method for particle-in-cell simulations, Comput. Phys. Commun. 322, 110054 (2026).
  26. S. Kalmykov et al., Electron self-injection and trapping into an evolving plasma bubble, Phys. Rev. Lett. 103, 135004 (2009).

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Phys. Rev. Research 8, 023080– Published 27 April, 2026
  • Received 16 December 2025
  • Accepted 22 March 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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