INFN-Milano and Università di Milano, Via Celoria, 16 20133 Milano, Italy.
Phys Rev Lett. 2013 Sep 13;111(11):114802. doi: 10.1103/PhysRevLett.111.114802.
We present the experimental demonstration of a new scheme for the generation of ultrashort pulse trains based on free-electron-laser (FEL) emission from a multipeaked electron energy distribution. Two electron beamlets with energy difference larger than the FEL parameter ρ have been generated by illuminating the cathode with two ps-spaced laser pulses, followed by a rotation of the longitudinal phase space by velocity bunching in the linac. The resulting self-amplified spontaneous emission FEL radiation, measured through frequency-resolved optical gating diagnostics, reveals a double-peaked spectrum and a temporally modulated pulse structure.
我们提出了一种基于多峰电子能分布的自由电子激光（FEL）发射产生超短脉冲串的新方案的实验演示。通过用两个 ps 间隔的激光脉冲照射阴极，随后在直线加速器中通过速度聚束使纵向相空间旋转，产生了能量差大于 FEL 参数 ρ 的两个电子束。通过频率分辨光学门控诊断测量的自生放大自发辐射 FEL 辐射显示出双峰光谱和时间调制的脉冲结构。
