Ultrafast Dissociation in Core-Ionized HBr Dications

Area of Science:

• Chemical Physics
• Atomic and Molecular Physics
• Quantum Chemistry

Background:

• Core-hole ionization leads to molecular fragmentation.
• Auger decay is a key process following core ionization.
• Understanding dissociation dynamics is crucial for molecular physics.

Purpose of the Study:

• To investigate ultrafast dissociation dynamics in core-ionized HBr.
• To demonstrate dissociation on a timescale faster than core-hole lifetime.
• To explore the role of electronic configuration mixing in potential energy surfaces.

Main Methods:

• Utilized multielectron-ion coincidence spectroscopy.
• Analyzed HBr subjected to core ionization.
• Identified atomic Auger lines from fragment ions.

Main Results:

• Observed sharp atomic Auger lines from HBr2+ (Br 3d)-1(4sσ)-1.
• Demonstrated dissociation of the core-ionized state on a sub-picosecond timescale.
• Indicated strong potential repulsion due to configuration mixing.

Conclusions:

• Provided evidence for ultrafast dissociation in a core-ionized state.
• Showed that doubly charged states with core holes can exhibit strong repulsion.
• Highlighted the influence of valence-hole configurations on molecular dynamics.