Table-top source for x-ray absorption spectroscopy with photon energies up to 350 eV.

Area of Science:

• Physics
• Materials Science
• Spectroscopy

Background:

• X-ray Absorption Spectroscopy (XAS) is a powerful technique for material characterization.
• Traditional XAS setups often require large-scale synchrotron facilities.
• Developing compact, laboratory-based XAS sources is highly desirable.

Purpose of the Study:

• To demonstrate a novel table-top X-ray Absorption Spectroscopy (XAS) system.
• To utilize high harmonic generation (HHG) for producing X-ray radiation.
• To showcase the system's capability for near-edge X-ray absorption fine structure (NEXAFS) spectroscopy.

Main Methods:

• A table-top setup employing high harmonic generation (HHG) in noble gases was developed.
• Sub-millijoule, 1550 nm pump pulses were used to generate broadband HHG from 70-350 eV.
• Achieved millimeter coherence lengths by operating in the nonadiabatic regime of harmonic generation.

Main Results:

• Broadband high harmonic generation (HHG) in the 70-350 eV range was successfully demonstrated.
• High coherence lengths for HHG were achieved, enabling efficient spectroscopy.
• Near edge X-ray absorption fine structure (NEXAFS) spectroscopy was performed on boron foil and hexagonal boron nitride (hBN).

Conclusions:

• The developed table-top HHG-based XAS system is capable of performing high-resolution spectroscopy.
• The femtosecond pulse duration allows for time-resolved pump-probe XAS experiments.
• This compact setup offers a promising alternative to large-scale synchrotron facilities for certain XAS applications.