Bermúdez Macias Ivette J, Düsterer Stefan, Ivanov Rosen, Liu Jia, Brenner Günter, Rönsch-Schulenburg Juliane, Czwalinna Marie K, Yurkov Mikhail V
Opt Express. 2021 Mar 29;29(7):10491-10508. doi: 10.1364/OE.419977.
Self-amplified spontaneous emission (SASE) pulses delivered by free electron lasers (FELs) are inherently fluctuating sources; each pulse varies in energy, duration, arrival time and spectral shape. Therefore, there is strong demand for a full characterization of the properties of SASE radiation, which will facilitate more precise interpretation of the experimental data taken at SASE FELs. In this paper, we present an investigation into the fluctuations of pulse duration, spectral distribution, arrival time and pulse energy of SASE XUV pulses at FLASH, both on a shot-to-shot basis and on average over many pulses. With the aid of simulations, we derived scaling laws for these parameters and disentangled the statistical SASE fluctuations from accelerator-based fluctuations and measurement uncertainties.
自由电子激光器（FEL）产生的自放大自发辐射（SASE）脉冲本质上是波动源；每个脉冲在能量、持续时间、到达时间和光谱形状上都会有所变化。因此，对SASE辐射特性进行全面表征的需求十分强烈，这将有助于更精确地解释在SASE FEL上获取的实验数据。在本文中，我们对FLASH装置上SASE极紫外脉冲的脉冲持续时间、光谱分布、到达时间和脉冲能量的波动进行了研究，包括逐次测量以及对多个脉冲的平均测量。借助模拟，我们推导了这些参数的标度律，并将基于加速器的波动和测量不确定性中的统计SASE波动区分开来。
