1 SLAC National Accelerator Laboratory , Linac Coherent Light Source , Menlo Park , CA 94025 , USA.
2 SLAC National Accelerator Laboratory , Stanford Pulse Institute , Menlo Park , CA 94025 , USA.
Philos Trans A Math Phys Eng Sci. 2019 May 20;377(2145):20180386. doi: 10.1098/rsta.2018.0386.
The ability to produce ultrashort, high-brightness X-ray pulses is revolutionizing the field of ultrafast X-ray spectroscopy. Free-electron laser (FEL) facilities are driving this revolution, but unique aspects of the FEL process make the required characterization and use of the pulses challenging. In this paper, we describe a number of developments in the generation of ultrashort X-ray FEL pulses, and the concomitant progress in the experimental capabilities necessary for their characterization and use at the Linac Coherent Light Source. This includes the development of sub-femtosecond hard and soft X-ray pulses, along with ultrafast characterization techniques for these pulses. We also describe improved techniques for optical cross-correlation as needed to address the persistent challenge of external optical laser synchronization with these ultrashort X-ray pulses. This article is part of the theme issue 'Measurement of ultrafast electronic and structural dynamics with X-rays'.
产生超短、高光强 X 射线脉冲的能力正在彻底改变超快 X 射线光谱学领域。自由电子激光（FEL）设施正在推动这一革命，但 FEL 过程的独特方面使得对脉冲的特性描述和使用具有挑战性。在本文中，我们描述了在产生超短 X 射线 FEL 脉冲方面的一些进展，以及在林可coherent 光源（Linac Coherent Light Source）对其进行特性描述和使用所需的实验能力方面的相应进展。这包括亚飞秒硬 X 射线和软 X 射线脉冲的产生，以及这些脉冲的超快特性描述技术。我们还描述了改进的光学互相关技术，以解决外部光学激光与这些超短 X 射线脉冲同步的持续挑战。本文是主题为“用 X 射线测量超快电子和结构动力学”的特刊的一部分。
