论文标题
直接激光加速对低密度自我调节的激光韦克菲尔德加速器中高能电子光谱的主要贡献
Predominant Contribution of Direct Laser Acceleration to High-Energy Electron Spectra in a Low-Density Self-Modulated Laser Wakefield Accelerator
论文作者
论文摘要
从低密度（$ 3 \ times10^{17} $ 〜cm $ $^{ - 3} $）自调制的激光Wakefield Accelerator（SM-LWFA）的两个温度相对论电子频谱被观察到温度在$ 19 \ pm0.65 $ $ 46 \ $ 46 \ pm2.45 $ 22.45 $ 22.46 \ mev之间过渡到过渡时。当电子与激光极化正交分散时，它们的光谱高于60 MEV，显示了直接激光加速（DLA）的分叉结构特征。在Quasi-3d \ textsc {Osiris}中复制了两个温度的分布和叉子结构，对1-PS的相互作用，中等振幅（$ a_ {0} = 2.7 $）激光脉冲与低密度等离子体的相互作用进行了模拟。粒子跟踪表明，虽然SM-LWFA机制占主导地位以下40 MEV，但最高能量（$> 60美元的MEV）电子通过DLA获得了大部分能量。通过将模拟电场分离为模式，显示DLA主导的电子与纵向激光场的显着能量与紧密的聚焦几何形状失去了重要的能量，从而比以前可能更准确地衡量了净DLA能量增益。
The two-temperature relativistic electron spectrum from a low-density ($3\times10^{17}$~cm$^{-3}$) self-modulated laser wakefield accelerator (SM-LWFA) is observed to transition between temperatures of $19\pm0.65$ and $46\pm2.45$ MeV at an electron energy of about 100 MeV. When the electrons are dispersed orthogonally to the laser polarization, their spectrum above 60 MeV shows a forking structure characteristic of direct laser acceleration (DLA). Both the two-temperature distribution and the forking structure are reproduced in a quasi-3D \textsc{Osiris} simulation of the interaction of the 1-ps, moderate-amplitude ($a_{0}=2.7$) laser pulse with the low-density plasma. Particle tracking shows that while the SM-LWFA mechanism dominates below 40 MeV, the highest-energy ($>60$ MeV) electrons gain most of their energy through DLA. By separating the simulated electric fields into modes, the DLA-dominated electrons are shown to lose significant energy to the longitudinal laser field from the tight focusing geometry, resulting in a more accurate measure of net DLA energy gain than previously possible.
