A laboratory five-crystal x-ray emission spectrometer in von Hámos geometry

X-ray emission spectroscopy (XES) is a powerful, element-specific tool for probing chemical valence states and electronic structures. While XES has traditionally been limited to high-flux synchrotron facilities, the move toward laboratory-based XES is crucial for routine characterization and long-term in situ studies. We report the development of a laboratory-based five-crystal XES spectrometer based on the von Hámos geometry, using crystal analyzers with a bending radius of 500 mm. In contrast to scanning-based Rowland configurations, this energy-dispersive setup enables simultaneous data collection across the entire spectral range without mechanical scanning, thereby ensuring temporal consistency across the spectrum. A bending radius of 500 mm was selected for the crystal analyzers to optimize the trade-off between collection efficiency, energy resolution, and the spatial requirements of complex sample environments. The impact of source size and focal spot alignment on energy resolution was systematically evaluated. Kα spectra of various Cu and Fe compounds were collected using the Si(444) and Si(333) Bragg reflections, respectively. Deconvolution of the metallic Cu spectrum revealed an instrumental broadening of 1.03 eV. Furthermore, the Kα1 peak positions were extracted to demonstrate the sensitivity of our laboratory system to subtle changes in the chemical environment, as validated by a linear correlation between the Kα1 energy shifts and Bond Valence Sums. This high-efficiency, high-resolution spectrometer provides a robust platform for routine chemical state analysis and in situ characterization in the laboratory.