Approaching the Lower Temporal Limit of Laser-Produced Plasma Sources for Table-Top Soft X-Ray NEXAFS Measurements

Area of Science:

• Physics
• Materials Science
• Chemistry

Background:

• Time-resolved X-ray absorption spectroscopy is vital for understanding dynamic processes in molecular and material systems.
• Table-top sources for pulsed X-rays are advancing, enabling more accessible research.
• Laser-produced plasma (LPP) sources offer potential for high-resolution X-ray generation.

Purpose of the Study:

• To characterize a novel table-top laser-produced plasma (LPP) source for soft X-ray (SXR) and near-edge X-ray absorption fine structure (NEXAFS) measurements.
• To evaluate the performance of a 23 ps pulse duration LPP source against longer pulse duration sources.
• To demonstrate the feasibility of high temporal resolution X-ray absorption studies using compact sources.

Main Methods:

• Utilized a table-top LPP source driven by a 23 ps pulsed laser.
• Performed soft X-ray (SXR) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy.
• Characterized source parameters including brilliance, resolution, and stability.
• Acquired NEXAFS spectra of Si3N4 and TiO2 thin films.

Main Results:

• The 23 ps LPP source achieved high temporal resolution for X-ray absorption measurements.
• Despite lower SXR flux compared to longer pulse sources, high signal-to-noise ratios (100) and resolving power (E/ΔE=424) were obtained.
• Measurement acquisition times were reduced to 2.5 minutes.
• Source instability due to gas jet nozzle degradation was identified and potential solutions noted.

Conclusions:

• Table-top LPP sources with short pulse durations are feasible for time-resolved X-ray absorption spectroscopy.
• This technology enables higher temporal resolution studies of molecular and material dynamics.
• Further optimization of source design, particularly nozzle stability, is recommended for long-term applications.