Foil backlighter development at the OMEGA laser facility for extended x-ray absorption fine structure experiments

Area of Science:

• * Plasma Physics
• * Materials Science
• * High-Energy-Density Physics

Background:

• * Extended X-ray Absorption Fine Structure (EXAFS) requires bright, continuous X-ray sources and high spectral resolution.
• * Laser-driven dynamic compression necessitates optimized X-ray backlighters for EXAFS measurements.

Purpose of the Study:

• * To characterize the X-ray emission spectra of various foil backlighters under laser irradiation.
• * To provide critical data for optimizing backlighter performance in dynamic compression EXAFS experiments.

Main Methods:

• * Experiments conducted at the OMEGA laser facility.
• * Characterization of titanium, iron, germanium, molybdenum, silver, and gold foil backlighters.
• * X-ray spectra recorded using a dual crystal spectrometer (DCS) covering 11 keV-45 keV and 19 keV-90 keV energy bands.

Main Results:

• * Detailed spectral intensity data were obtained for different foil materials and laser energies (3 kJ-12 kJ).
• * The dual crystal spectrometer (DCS) was calibrated for inter-campaign intensity comparisons.
• * This provides a foundational dataset for selecting optimal backlighters.

Conclusions:

• * The study successfully characterized multiple foil backlighters for laser-driven dynamic compression EXAFS.
• * The collected spectral data are vital for improving the efficiency and resolution of these experiments.
• * This research contributes to advancing in-situ material analysis under extreme conditions.