介质激光加速器中电子能量增益与三角光栅结构底角的关系
Electron energy gain in a dielectric laser accelerator as a function of the base angle of a triangular grating structure
浏览论文内容
中文总结 AI 辅助
本文通过粒子模拟研究三角光栅DLAs的电子加速，明确光栅底角等参数对加速率的影响，获得特定参数下的最大加速率，为优化三角光栅DLAs设计提供定量依据。
中文摘要 AI 辅助
介质激光加速器（DLAs）是传统射频加速器的紧凑且高性价比替代方案。尽管已研究了多种光栅几何结构，但对三角轮廓、特别是锯齿状光栅轮廓底角的影响仍缺乏全面研究。本文展示了基于三角轮廓双光栅的DLAs中电子加速的数值粒子模拟（PIC）结果：激光束入射的其中一块光栅为透明，另一块光栅对激光脉冲可为透明或反射，第一块光栅的几何结构固定。系统研究了第二块光栅的底角（α=5°-44°）、空间取向、是否存在反射金涂层，以及入射激光脉冲的形状（平面波与高斯轮廓）对加速率的影响。结果显示这些参数间存在复杂相互作用：对于初始能量10 MeV的电子束，当左旋反射光栅底角α=10°、由高斯脉冲激发时，获得最大加速率345 MeV/m；平面波激发时，底角α=25°的左旋反射光栅提供325 MeV/m的加速率。研究表明，对于单束团注入，可在0.5 fs的时间窗口内获得接近最大能量增益。所得结果为优化三角光栅DLAs设计提供了定量依据，凸显锯齿轮廓底角与光栅类型对实现下一代加速器高加速率的重要作用。
英文摘要
Dielectric laser accelerators (DLAs) represent a compact and cost-effective alternative to conventional RF accelerators. Despite the various grating geometries already studied, a comprehensive investigation of triangular profiles, particularly the effect of the base angle of the saw-tooth grating profile, remains insufficient. This paper presents the results of numerical particle-in-cell (PIC) simulations of electron acceleration in DLAs based on double gratings with a triangular profile. One of the gratings, onto which the laser beam is incident, is transparent, while the second grating was either transparent or reflective for the laser pulse. The geometry of the first grating was fixed. A systematic study was conducted on the influence of the base angle of the second grating ($α= 5^\circ - 44^\circ$), its spatial orientation, the presence of a reflective gold coating, and the shape of the incident laser pulse (plane wave versus Gaussian profile) on the acceleration rate. The results reveal a complex interplay between these parameters. For an electron beam with an initial energy of 10 MeV, a maximum accelerating rate of 345 MeV/m was achieved for the structure with a left-handed reflective grating and a base angle of $α= 10^\circ$ when excited by a Gaussian pulse. Under plane-wave excitation, the left-handed reflective grating with $α= 25^\circ$ provided a rate of 325 MeV/m. It is shown that for single-bunch injection, nearly the maximum energy gain can be attained within a temporal window of 0.5 fs. The obtained results provide a quantitative basis for optimizing DLA designs with triangular gratings, highlighting the significant role of the saw-tooth profile base angle and the grating type in achieving high rates for next-generation accelerators.
