Dense Attosecond Electron Sheets from Laser Wakefields Using an Up-Ramp Density Transition
Dense Attosecond Electron Sheets from Laser Wakefields Using an Up-Ramp Density Transition
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DOI：
10.1103/physrevlett.110.135002
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发表时间：
2013-03-26
影响因子：
8.6
通讯作者：
Zhang, J.
中科院分区：
文献类型：
--
作者：
Li, F. Y.;Sheng, Z. M.;Zhang, J.
基于粒子模拟方法研究了电子在激光驱动的韦克菲尔德中的受控注入。关键的新颖成分是欠密等离子体靶，其具有上升斜坡密度分布，随后是平台和相当大的激光焦点直径，其导致激光韦克菲尔德的基本上一维（1D）状态，这不同于对于紧密聚焦的驱动光束发生的气泡（完全熄灭）状态。上升斜坡轮廓导致在上升斜坡-平台过渡处急剧发生1D波破碎。结果，它产生了一个极高密度的相对论性电子片（几纳米，相当于阿秒），在韦克菲尔德中被注入并加速。峰值电子能谱和高电荷（类似于nC）区分最终的片。DOI：10.1103/PhysRevLett.110.135002
Controlled electron injection into a laser-driven wakefield at a well defined space and time is reported based on particle-in-cell simulations. Key novel ingredients are an underdense plasma target with an up-ramp density profile followed by a plateau and a fairly large laser focus diameter that leads to an essentially one-dimensional (1D) regime of laser wakefield, which is different from the bubble (complete blowout) regime occurring for tightly focused drive beams. The up-ramp profile causes 1D wave breaking to occur sharply at the up-ramp-plateau transition. As a result, it generates an ultrathin (few nanometer, corresponding to attosecond duration), strongly overdense relativistic electron sheet that is injected and accelerated in the wakefield. A peaked electron energy spectrum and high charge (similar to nC) distinguish the final sheet. DOI: 10.1103/PhysRevLett.110.135002