2025/08/14 by Angella, A., Löfquist, E., Gustafsson, C. +7 · 1 citation
#Accelerator Physics (physics.acc-ph) #FOS: Physical sciences #Plasma Physics (physics.plasm-ph)
paper · doi:10.48550/arxiv.2508.10829
We report the first experimental observation of carrier-envelope phase-driven energy bunching in laser wakefield acceleration. Using a few-cycle (~9 fs), multi-terawatt laser pulse and ionization injection in a helium-nitrogen gas mixture, we observe electron spectra composed of multiple quasi-monoenergetic peaks with regular narrow energy spacing. This comb structure arises from intermittent injection from successive half-cycles of the laser field, enabled by the evolving carrier-envelope phase during propagation in the plasma. These findings establish sub-cycle ionization injection as a potential route to attosecond control in plasma acceleration, enabling injection and beam structuring synchronized to the optical waveform on sub-femtosecond timescales.