X-ray optics for the cavity-based X-ray free-electron laser

Area of Science:

• Physics
• Optics
• Materials Science

Background:

• Cavity-based X-ray free-electron lasers (CBXFELs) represent a promising advancement for generating fully coherent X-ray pulses.
• The development of CBXFELs necessitates specialized optical components capable of preserving wavefronts and minimizing losses within the X-ray cavity.

Purpose of the Study:

• To design, manufacture, and characterize critical X-ray optical components for a CBXFEL cavity.
• To assess the suitability of these components for enabling high-performance FEL interactions and achieving saturation.

Main Methods:

• Design and fabrication of near-100%-reflectivity diamond crystal mirrors and thin diamond membranes.
• Development of beryllium refractive lenses and channel-cut silicon monochromators for aberration-free focusing and outcoupling.
• Characterization of all optical components at the Advanced Photon Source.

Main Results:

• Successful design and manufacturing of high-reflectivity diamond mirrors and a diamond drumhead crystal with thin membranes.
• Fabrication of beryllium refractive lenses and silicon monochromators meeting CBXFEL specifications.
• Experimental validation of all components' performance at the Advanced Photon Source, confirming their suitability for the CBXFEL cavity.

Conclusions:

• The developed X-ray optical components are suitable for use in CBXFEL cavities.
• These components are essential for the successful operation and advancement of future fully coherent X-ray sources.
• The collaborative effort has yielded key technologies for next-generation FEL facilities.