Imaging molecular structure through femtosecond photoelectron diffraction on aligned and oriented gas-phase molecules

Area of Science:

• Atomic and Molecular Physics
• Ultrafast Science
• Chemical Physics

Background:

• Photoelectron diffraction is a powerful technique for probing molecular structure.
• Time-resolved studies offer insights into dynamic molecular processes.
• Advancements in X-ray free-electron lasers (XFELs) enable new experimental capabilities.

Purpose of the Study:

• To develop and demonstrate femtosecond time-resolved photoelectron diffraction on gas-phase molecules.
• To investigate molecular structure and dynamics using a pump-probe setup.
• To assess the impact of laser alignment on molecular experiments.

Main Methods:

• Utilizing a pump-probe setup combining optical lasers and an X-ray free-electron laser.
• Performing femtosecond time-resolved photoelectron diffraction experiments.
• Measuring photoelectron angular distributions of laser-aligned molecules.

Main Results:

• Presented results from experiments on laser-aligned 1-ethynyl-4-fluorobenzene and dissociating 1,4-dibromobenzene.
• Analyzed photoelectron angular distributions to understand molecular structure.
• Investigated the influence of strong nanosecond laser pulses on electron and ion spectra.

Conclusions:

• Demonstrated progress in femtosecond time-resolved photoelectron diffraction for gas-phase molecules.
• Highlighted the significant influence of laser alignment pulses on experimental outcomes.
• Provided insights for optimizing future time-resolved photoelectron diffraction experiments.