200-mm segmented cylindrical figured crystal for von Hamos x-ray spectrometer

Area of Science:

• Materials Science
• Spectroscopy
• Condensed Matter Physics

Background:

• X-ray emission spectroscopy (XES) is crucial for elemental characterization.
• Existing spectrometers often face limitations in efficiency and simultaneous spectral line measurement.
• The von Hamos geometry offers potential for improved XES performance.

Purpose of the Study:

• To describe a novel von Hamos Bragg crystal spectrometer developed for XES applications.
• To evaluate the spectrometer's efficiency and energy resolution.
• To demonstrate its capability for simultaneous measurement of characteristic X-ray emission lines.

Main Methods:

• Utilized diced Si crystals of various orientations ([111], [110], [100], [311]) on a planoconcave substrate.
• Employed a 200 mm crystal analyzer length to enhance spectrometer efficiency.
• Measured emission spectra of Cu, Fe foils and elastic scattering from Al foil.
• Tested different crystal analyzers (Si(440), Si(444), Si(800), Si(933)) at specific X-ray photon energies.
• Constructed a mixed crystal analyzer for simultaneous Kα and Kβ line detection.

Main Results:

• Spectrometer efficiency significantly increased with a 200 mm crystal analyzer length.
• Optimal energy resolution was achieved with the analyzer placed near 80° to the sample.
• Demonstrated simultaneous measurement of Fe Kα1, Kα2, and Kβ emission lines using a mixed crystal analyzer.
• Successfully measured emission spectra of Cu and Fe foils, and elastic scattering from Al foil.

Conclusions:

• The developed von Hamos spectrometer offers enhanced efficiency and simultaneous spectral line measurement capabilities for XES.
• This advancement is particularly beneficial for in situ and time-resolved XES studies.
• The high-efficiency spectrometer facilitates elemental characterization from low-intensity XES emission lines in catalytic reactions.