Milli-electronvolt monochromatization of hard X-rays with a sapphire backscattering monochromator

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nuclear Physics

Background:

• High-resolution X-ray spectroscopy requires narrow bandwidth monochromators.
• Sapphire crystals offer potential for advanced optical applications due to their properties.

Purpose of the Study:

• To develop and characterize a sapphire backscattering monochromator with ultra-narrow bandwidth for hard X-rays.
• To demonstrate the monochromator's capability for nuclear inelastic scattering experiments.

Main Methods:

• Studied optical quality of multiple sapphire crystals to select the optimal one.
• Optimized crystal volume and quality for narrow energy bandwidth.
• Tested the monochromator at specific nuclear resonance energies (20-40 keV) using various isotopes.

Main Results:

• Achieved an energy bandwidth of 1.1(1) meV for hard X-rays (20-40 keV).
• Successfully operated the monochromator at nuclear resonance energies of Sb-121, Te-125, Sn-119, Sm-149, and Eu-151.
• Demonstrated applicability for nuclear inelastic scattering experiments.

Conclusions:

• The sapphire backscattering monochromator provides a highly precise tool for hard X-ray applications.
• The developed monochromator is suitable for sensitive nuclear inelastic scattering studies on selected isotopes.