Molecule effect in inner shell sequential double ionization

Area of Science:

• Atomic and Molecular Physics
• Quantum Optics
• Chemical Physics

Background:

• Sequential inner shell two-photon double ionization (TPDI) is a complex process involving multiple photons interacting with atoms or molecules.
• Understanding the angular distribution of emitted photoelectrons provides crucial insights into ionization dynamics.
• Previous studies often focused on atomic systems, with less emphasis on molecular effects.

Purpose of the Study:

• To present a theoretical framework for analyzing the angular distribution of photoelectrons in molecular TPDI.
• To investigate the influence of molecular structure on ionization dynamics.
• To provide a computational tool for simulating and studying TPDI in polyatomic systems.

Main Methods:

• Development of a theoretical framework for sequential inner shell TPDI.
• Numerical calculation of sequential double ionization for the 4d shells of iodine in CH3I.
• Utilizing both length and velocity gauges for calculations.
• Comparison with atomic xenon to highlight molecular effects.

Main Results:

• The angular anisotropy parameters for sequential TPDI were calculated for CH3I.
• A significant influence of molecular structure on the anisotropy parameter for the second ionization step was observed.
• The calculated parameters for CH3I differ from those of atomic xenon, underscoring molecular effects.

Conclusions:

• The molecular structure strongly influences the angular distribution of photoelectrons in sequential TPDI.
• This provides a sensitive method to probe photoionization dynamics in polyatomic systems.
• The developed computational code enables further theoretical studies of molecular effects in inner-shell double ionization.