Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China.
SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
Phys Rev Lett. 2014 Oct 31;113(18):184802. doi: 10.1103/PhysRevLett.113.184802. Epub 2014 Oct 30.
It has long been known that lasers can interact with relativistic electrons in magnetic undulators to imprint sinusoidal modulations that can be used to slice electrons into microbunches equally separated at the laser wavelength. Here we report on the first direct measurement of laser-induced microbunching of a relativistic electron beam with femtosecond resolution in the time domain. Using a modified zero-phasing technique to map the electron beam's temporal structures into the energy space, we show that this method can be used to directly quantify the time and spectral content of coherent current modulations imprinted on the beam for harmonic and multicolor lasing applications in accelerator-based light sources.
长期以来，人们已经知道激光可以与磁场中的相对论电子相互作用，从而产生正弦调制，可以用来将电子切成等间隔的激光波长的微束。在这里，我们报告了首次在时域中用飞秒分辨率直接测量激光诱导的相对论电子束微束化。我们使用一种改进的零相位技术将电子束的时域结构映射到能量空间，证明了该方法可用于直接量化相干电流调制在光束中的时间和光谱内容，这对于基于加速器的光源中的谐波和多色激光应用很有意义。
