High-Repetition-Rate Proton Acceleration Above 20 MeV from a Liquid Microjet at L3-HAPLS

ORAL

Abstract

High-flux, high-repetition-rate laser-driven proton beams are of interest for applications in inertial fusion energy, cancer therapy, and material damage studies. Realizing these beams requires stable, debris-free, self-refreshing targets compatible with modern high-repetition-rate lasers. Liquid microjets have demonstrated this capability in prior campaigns at ALEPH (CSU), Neptun (TAU), and Gemini (RAL), establishing them as an ideal platform for advanced ion acceleration. Building on this foundation, we implemented a converging liquid water jet target at the L3-HAPLS laser using the ELIMAIA beamline (30 fs, 1-5 J, 3.3 Hz) to explore advanced acceleration regimes and target density shaping. Over 19,000 shots, including 2,000 consecutive, were delivered, demonstrating robust and stable operation. We performed systematic scans of target thickness (0.5-1.7 µm), focal spot size, and laser phase. A synchronized few-mJ pre-pulse precisely controlled pre-expansion to access near-critical density conditions. Ion spectra and angular emission were characterized using absolutely calibrated Thomson parabola spectrometers, TOF detectors, and an ion imager. To monitor the interaction, we measured the laser specular reflection and transmission profiles, the reflected laser spectrum, and XUV emission from the plasma. This presentation will introduce the platform and highlight preliminary results demonstrating a stable, high-repetition-rate proton source exceeding 20 MeV.

*This work was funded by the DOE Office of Science, Fusion Energy Science under FWP100182 and in part by the NSF Grant No. 1632708. Portions of this research were carried out at the ELI Beamlines Facility, a European user facility operated by the Extreme Light Infrastructure ERIC. The authors would like to thank the ELIMAIA station team, the L3-HAPLS laser team and the support team involved in the experiment. The work was partially supported by the European Union, the Romanian Government and the Health Program, within the project "Medical applications of high-power lasers - Dr. LASER", SMIS Code: 326475. CAJP, JW, PP acknowledge the support of the Vulcan dark period community support programme 24-3.

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Publication: Treffert, F., et al, Physics of Plasmas 29, 123105 (2022).
Loughran, B., et al, High Power Laser Science and Engineering 11, e35 (2023).
Streeter, M.J.V., et al. Stable laser-acceleration of high-flux proton beams with plasma collimation. Nat Commun 16, 1004 (2025).

Presenters

  • Maxence Gauthier

    • SLAC National Accelerator Laboratory

Authors

  • Maxence Gauthier

    • SLAC National Accelerator Laboratory

  • Griffin D Glenn

    • SLAC National Accelerator Laboratory

  • Girik Jain

    • SLAC National Accelerator Laboratory

  • Stefano Faubel

    • SLAC National Accelerator Laboratory

  • Charlotte A Palmer

    • Queen's University Belfast

  • Peter Parsons

    • Queen's University Belfast

  • James Weeks

    • Queen's University Belfast

  • Stefan Popa

    • Extreme Light Infrastructure-Nuclear Physics (ELI-NP), Horia Hulubei National Institute of Physics and Nuclear Engineering (IFIN-HH)

  • Daniel Ursescu

    • Extreme Light Infrastructure-Nuclear Physics (ELI-NP), Horia Hulubei National Institute of Physics and Nuclear Engineering (IFIN-HH)

  • Raz H Levi

    • Tel Aviv University

  • Milenko Vescovi

    • Helmholtz-Zentrum Dresden-Rossendorf

  • Martin Rehwald

    • HZDR

  • Siegfried H Glenzer

    • SLAC National Accelerator Laboratory

  • Lorenzo Guiffrida

    • ELI Beamlines

  • Filip Grepl

    • ELI Beamlines

  • Francesco Schillaci

    • ELI Beamlines

  • Andriy Velyhan

    • ELI Beamlines

  • Maksym Tyrus

    • ELI Beamlines

  • Helena Lefebvre

    • ELI Beamlines