亚GeV级质子的双脉冲微喷嘴加速
Dual-pulse micronozzle acceleration of sub-GeV-class protons
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中文总结 AI 辅助
该研究提出双脉冲微喷嘴加速方案，通过延迟调谐同步窗口实现激光驱动质子锁相加速，减轻能量与效率权衡。模拟表明改进源于时间同步和几何限制，确立了锁相加速为紧凑型、高产亚GeV质子驱动器的实用设计原则。
中文摘要 AI 辅助
我们提出了一种双脉冲微喷嘴加速方案，可实现激光驱动质子的锁相加速，减轻最大质子能量与激光-质子转换效率之间的权衡。通过延迟调谐同步窗口，将整形预脉冲产生的紧凑质子前沿注入微喷嘴腔中由延迟主脉冲驱动的准静态轴向电场。锁相可保持质子束与加速场之间的相对相位，抑制热散束并延长加速阶段。在主脉冲强度约为10^21 W/cm^2时，可获得亚GeV质子截止能量，总激光-质子转换效率约为20%。能量高于100 MeV的质子效率超过约13%。模拟表明改进源于时间同步和几何限制。分析同步模型与模拟结果相符。三维粒子模拟证实了在狭缝喷嘴几何结构中锁相和光谱硬化得以保持，截止能量比无限制氢棒高约60%。这些结果确立了锁相加速作为用于次级粒子应用的紧凑型、高产亚GeV质子驱动器的实用设计原则。
英文摘要
We propose a dual-pulse micronozzle acceleration scheme that enables phase-locked acceleration of laser-driven protons, mitigating the trade-off between maximum proton energy and laser-to-proton conversion efficiency. A delay-tuned synchronization window injects a compact proton front generated by a shaping prepulse into a quasistatic axial electric field driven by a delayed main pulse in a micronozzle cavity. Phase locking preserves the relative phase between the proton bunch and the accelerating field, suppresses thermal debunching, and prolongs the acceleration stage. At main-pulse intensities of order 10^21 W/cm^2, sub-GeV proton cutoff energies are obtained with a total laser-to-proton conversion efficiency of about 20%. The efficiency for protons above 100 MeV exceeds about 13%, indicating preferential energy loading into a compact proton population. Simulations with an unconfined dual-pulse hydrogen rod show that the improvement results from temporal synchronization and geometric confinement, which sustain a long-lived axial accelerating channel. An analytical synchronization model agrees with the simulations. Three-dimensional particle-in-cell simulations confirm that phase locking and spectral hardening are preserved in slit-nozzle geometries, with cutoff energies about 60% higher than those of an unconfined hydrogen rod. These results establish phase-locked acceleration as a practical design principle for compact, high-yield sub-GeV proton drivers for secondary-particle applications.
