In this work, we present the CoESCA station for electron–electron coincidence spectroscopy from surfaces, built in a close collaboration between Uppsala University and Helmholtz-Zentrum Berlin at the BESSY II synchrotron facility in Berlin, Germany. We start with a detailed overview of previous work in the field of electron–electron coincidences, before we describe the CoESCA setup and its design parameters. The system is capable of recording shot-to-shot resolved 6D coincidence datasets, i.e. the kinetic energy and the two take off angles for both coincident electrons. The mathematics behind extracting and analysing these multi-dimensional coincidence datasets is introduced, with a focus on coincidence statistics, resulting in fundamental limits of the signal-to-noise ratio and its implications for acquisition times and the size of the raw data stream. The functionality of the CoESCA station is demonstrated for the example of Auger electron–photoelectron coincidences from silver surfaces for photoelectrons from the Ag 3d core levels and their corresponding MNN Auger electrons. The Auger spectra originating from the different core levels, $3d_{3∕2}$ and $3d_{5∕2}$ could be separated and further, the two-hole state energy distributions were determined for these Auger decay channels.

在这项工作中，我们展示了CoESCA站用于表面电子-电子符合光谱学，它是由Uppsala大学和Helmholtz-Zentrum Berlin在德国柏林的BESSY II同步加速器设施之间紧密合作建立的。在描述CoESCA设置及其设计参数之前，我们先对电子-电子符合领域的先前工作进行详细的概述。该系统能够记录逐枪分辨的6D重合数据集，即两个重合电子的动能和两个起飞角。介绍了提取和分析这些多维符合性数据集的背后的数学，重点是符合性统计数据，导致信噪比的基本限制及其对采集时间和原始数据流大小的影响。CoESCA站的功能以Ag 3d核心能级的光电子及其对应的MNN Auger电子的银表面俄歇电子与光电子重合为例进行了演示。来自不同核心水平的俄歇谱，$3d_{3∕\mathrm{2个}}$ 和 $3d_{5∕\mathrm{2个}}$ 可以分离并进一步确定这些俄歇衰变通道的两孔态能量分布。