AI 中文总结
研究相对论激光驱动等离子体通道中直接激光加速的电子注入，提出波前引导注入机制，解释其高电荷能力，为紧凑型DLA粒子与辐射源研发提供物理支撑
AI 中文摘要
我们采用粒子模拟方法研究相对论激光驱动等离子体通道中直接激光加速（DLA）的电子注入过程，识别并表征了一种波前引导注入机制，该机制中电子通过激光脉冲前沿的密度堆积层持续馈入等离子体通道。相空间分析显示，堆积层内存在局域化的可注入区域，表明仅选定的电子子集满足后续直接激光加速所需条件。该机制为DLA的高电荷能力提供了物理解释，阐明了电子如何持续供给加速通道。除持续供给过程外，注入动力学还受激光脉冲前沿载波相位的周期性变化调制，发现注入电子的空间位置与激光相位调制下形成的磁岛结构密切相关，说明激光波前不仅提供电子，还组织电子进入加速通道。这些发现深化了对相对论激光驱动亚临界密度等离子体通道中高能电子产生的物理理解，与紧凑型基于DLA的粒子及辐射源的研发相关。
英文摘要
We investigate electron injection into direct laser acceleration (DLA) in relativistic laser-driven plasma channels using particle-in-cell simulations. We identify and characterize a wavefront-guided injection mechanism, in which electrons are continuously fed into the plasma channel through the density pile-up layer at the laser-pulse front. Phase-space analysis reveals a localized injectable region within the pile-up layer, indicating that only a selected subset of electrons satisfies the conditions required for the subsequent direct laser acceleration. This mechanism provides a physical interpretation for the high-charge capability of DLA by explaining how electrons are continuously supplied to the accelerating channel. Beyond this continuous supply process, the injection dynamics are further modulated by the periodic variation of the carrier phase at the laser-pulse front. The spatial locations of injected electrons are found to be closely associated with magnetic-island structures formed under laser-phase modulation, suggesting that the laser wavefront not only supplies electrons but also organizes their entry into the accelerating channel. These findings advance the physical understanding of energetic-electron generation in relativistic laser-driven subcritical-density plasma channels and are relevant to the development of compact DLA-based particle and radiation sources.
Journal refPlasma Phys. Control. Fusion 68, 095028 (2026)
