Kinetic Energy-Broadened Spatial Map Imaging for Recovering Dynamical Information

Area of Science:

• Atomic and Molecular Physics
• Physical Chemistry
• Spectroscopy

Background:

• Velocity map imaging (VMI) is a key technique for studying light-matter interactions.
• Existing VMI methods provide limited kinetic energy and angular information.
• There is a need for advanced imaging techniques to probe photophysical processes with higher resolution.

Purpose of the Study:

• To demonstrate the kinetic energy-broadened spatial map imaging (KESMI) technique as a novel method for analyzing photophysical processes.
• To recover kinetic energy (KE) and angular recoil information of photoelectrons (PEs).
• To develop a global model for understanding KESMI patterns in photoelectron spectroscopy.

Main Methods:

• Utilizing a VMI system in different out-of-focus modes to perform KESMI.
• Analyzing characteristic stripe and step patterns in vertical intensity profiles of KESMIs.
• Developing and applying a global model to interpret KESMI signatures.
• Simulating and measuring KESMIs for Ar ionization and H2O quantum state ionization.

Main Results:

• KESMI successfully recovers KE and angular recoil information from photophysical processes.
• A global model was developed to understand the stripe and step patterns observed in KESMIs.
• The model accurately relates observed KESMI features to predicted discrete KEs and angular distributions.
• The velocity distribution of photoelectrons from H2O ionization was derived using KESMI, validating the technique.

Conclusions:

• KESMI is a feasible and powerful technique for analyzing photophysical processes.
• The developed global model provides a robust framework for interpreting KESMI data.
• KESMI offers a promising alternative or complement to VMI for detailed photoelectron spectroscopy.
• This technique holds significant potential for future research in light-matter interactions.