Note: A novel normalization scheme for laser-based plasma x-ray sources

Area of Science:

• Ultrafast Science
• Materials Science
• X-ray Physics

Background:

• Ultrafast X-ray diffraction requires stable X-ray sources.
• Laser-driven plasma X-ray sources offer high repetition rates but suffer intensity fluctuations.
• Existing normalization methods can be complex or insufficient for high-repetition-rate systems.

Purpose of the Study:

• To develop and validate a simple, reliable normalization method for kHz repetition rate laser pump-X-ray probe systems.
• To minimize the impact of X-ray pulse intensity fluctuations on ultrafast X-ray diffraction data.
• To demonstrate the method's efficacy in high-resolution measurements.

Main Methods:

• Setup of a kHz repetition rate laser pump-X-ray probe system utilizing a laser-driven plasma X-ray source.
• Development of a simultaneous sample and reference signal recording technique using a single X-ray area detector.
• Application of the normalization method to reflectivity oscillation measurements of a superlattice sample.

Main Results:

• A robust normalization approach was successfully implemented.
• The method effectively mitigated data quality issues caused by X-ray pulse intensity variations.
• Sub-picosecond resolution reflectivity oscillation measurements of a superlattice were achieved with improved accuracy.

Conclusions:

• The developed normalization method is effective for kHz laser pump-X-ray probe systems.
• This approach enhances the reliability and precision of ultrafast X-ray diffraction experiments.
• The technique is suitable for studying dynamic processes in materials with sub-picosecond resolution.