First observation of novel satellites using high-resolution XR-HERFD measurement of Zn Kα emission

We discover satellites in Zn at emission energies of 8670-8675 eV. The satellite is detected with a significance exceeding 51.6 [Formula: see text] per pixel, enabled by the exceptional signal-to-noise ratio of the new dataset and novel technique. We have created the eXtended-range high-energy-resolution fluorescence detection (XR-HERFD) technique and applied it to Zn (Z = 30) using a novel 14-crystal analyser spectrometer. For this current work, data collection developed the first DOSE-S collection macros for Discovery-Onset-Spectrometry-Evolution of new Satellite processes. The energy dependence of the discovered satellite is tracked from the onset of the process at approximately 10791.7 eV through its evolution to higher energies. The satellite exhibits a clear manifold structure, consistent with multiple shake-off processes. We develop and apply Principal Component Analysis (PCA) and independently isolate the manifold of the satellite and prove the incident-energy evolution. We also fit the evolution to theoretical quantum mechanical models of such processes to provide strong confirmation of the physical origin. These findings demonstrate XR-HERFD's capability to resolve weak many-body features and suggest new opportunities for studying shake processes and the many-body reduction factor [Formula: see text]. By resolving these satellites in what many people believed was a nominally simple [Formula: see text] metal and revealing rich many-body behaviour, this work opens a pathway to a physically grounded understanding of many-body effects in X-ray spectroscopy.