Photoelectron diffraction from laser-aligned molecules with X-ray free-electron laser pulses

Area of Science:

• Atomic and Molecular Physics
• Chemical Physics
• Materials Science

Background:

• X-ray photoelectron diffraction (XPD) is a powerful surface science technique.
• Understanding molecular structure is crucial for chemical and physical processes.
• Laser alignment and X-ray free-electron lasers (XFELs) offer new possibilities for molecular studies.

Purpose of the Study:

• To measure deep inner-shell 2p X-ray photoelectron diffraction (XPD) patterns from laser-aligned I2 molecules.
• To validate theoretical calculations against experimental XPD data.
• To establish a methodology for molecular structure determination using XPD.

Main Methods:

• Utilizing X-ray free-electron laser (XFEL) pulses for high-intensity X-ray generation.
• Employing laser alignment to orient I2 molecules parallel to the XFEL polarization vector.
• Measuring and analyzing deep inner-shell 2p XPD patterns.

Main Results:

• Successfully obtained XPD patterns from aligned I2 molecules.
• Demonstrated excellent agreement between experimental XPD patterns and theoretical calculations.
• Proposed a criterion for applying the molecular-structure-determination methodology to XPD data.

Conclusions:

• The study validates the use of XPD for analyzing molecular structures.
• The developed methodology represents a significant advancement in time-resolved molecular imaging.
• This work paves the way for future investigations into dynamic molecular processes.