Sadler James D, Nathvani Ricky, Oleśkiewicz Piotr, Ceurvorst Luke A, Ratan Naren, Kasim Muhammad F, Trines Raoul M G M, Bingham Robert, Norreys Peter A
Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU.
Central Laser Facility, STFC Rutherford Appleton Laboratory, Didcot, Oxon, OX11 0QX.
Sci Rep. 2015 Nov 16;5:16755. doi: 10.1038/srep16755.
State of the art X-ray Free Electron Laser facilities currently provide the brightest X-ray pulses available, typically with mJ energy and several hundred femtosecond duration. Here we present one- and two-dimensional Particle-in-Cell simulations, utilising the process of stimulated Raman amplification, showing that these pulses are compressed to a temporally coherent, sub-femtosecond pulse at 8% efficiency. Pulses of this type may pave the way for routine time resolution of electrons in nm size potentials. Furthermore, evidence is presented that significant Landau damping and wave-breaking may be beneficial in distorting the rear of the interaction and further reducing the final pulse duration.
目前，最先进的X射线自由电子激光设施可提供现有的最亮X射线脉冲，其能量通常为mJ，持续时间为几百飞秒。在此，我们展示了一维和二维粒子模拟，利用受激拉曼放大过程，结果表明这些脉冲以8%的效率被压缩成时间相干的亚飞秒脉冲。这种类型的脉冲可能为在纳米尺寸势场中对电子进行常规时间分辨铺平道路。此外，有证据表明，显著的朗道阻尼和波破裂可能有助于扭曲相互作用的尾部并进一步缩短最终脉冲持续时间。
