RIKEN SPring-8 Center, Kouto 1-1-1 Sayo, Hyogo 679-5148, Japan.
Phys Rev Lett. 2012 Oct 5;109(14):144801. doi: 10.1103/PhysRevLett.109.144801. Epub 2012 Oct 1.
We determined the pulse duration of x-ray free electron laser light at 10 keV using highly resolved single-shot spectra, combined with an x-ray free electron laser simulation. Spectral profiles, which were measured with a spectrometer composed of an ultraprecisely figured elliptical mirror and an analyzer flat crystal of silicon (555), changed markedly when we varied the compression strength of the electron bunch. The analysis showed that the pulse durations were reduced from 31 to 4.5 fs for the strongest compression condition. The method, which is readily applicable to evaluate shorter pulse durations, provides a firm basis for the development of femtosecond to attosecond sciences in the x-ray region.
我们使用高分辨率单次光谱，结合自由电子激光模拟，确定了 10keV 时的 X 射线自由电子激光光的脉冲持续时间。当我们改变电子束的压缩强度时，使用由超精密加工的椭圆反射镜和硅（555）分析晶体组成的光谱仪测量的光谱轮廓发生了明显变化。分析表明，在最强的压缩条件下，脉冲持续时间从 31 到 4.5fs 减少。该方法易于应用于评估更短的脉冲持续时间，为 X 射线区域的飞秒到阿托秒科学的发展提供了坚实的基础。
