Resolving multiphoton processes with high-order anisotropy ultrafast X-ray scattering.

Area of Science:

• Chemical Physics
• Ultrafast Spectroscopy
• Molecular Dynamics

Background:

• Studying molecular dynamics requires high temporal and spatial resolution.
• Ultrafast X-ray scattering offers a powerful probe for transient molecular states.
• Anisotropy in scattering signals contains rich information about molecular motion.

Purpose of the Study:

• To present the first experimental results of ultrafast X-ray scattering on strongly driven molecular iodine.
• To develop and apply a method for analyzing high-order anisotropic components of scattering signals.
• To disentangle and characterize simultaneous dissociation and vibrational motions.

Main Methods:

• Experimental measurement of ultrafast X-ray scattering.
• Retrieval of high-order anisotropic scattering components.
• Legendre decomposition for signal analysis.
• Fourier analysis of simulated anisotropic scattering signals.

Main Results:

• Successful retrieval of high-fidelity high-order anisotropy components.
• Observation of simultaneous dissociation and vibrational motions.
• Assignment of dissociation velocities on Angstrom and femtosecond scales.
• Identification of multiple multiphoton transitions.

Conclusions:

• The developed Legendre decomposition method effectively analyzes anisotropic scattering data.
• Ultrafast X-ray scattering provides detailed insights into complex molecular dynamics.
• This approach enables de novo characterization of ultrafast molecular processes.