Observation of p-wave threshold behavior in electron attachment to F2 molecules

Area of Science:

• Chemical Physics
• Molecular Spectroscopy
• Quantum Mechanics

Background:

• Understanding electron attachment to molecules is crucial for plasma physics and atmospheric chemistry.
• Previous experimental studies on fluorine molecule (F2) electron attachment at low energies yielded conflicting results regarding threshold behavior.

Purpose of the Study:

• To accurately determine the low-energy electron attachment cross-section behavior for F2 molecules.
• To resolve discrepancies in previous experimental findings and confirm theoretical predictions.

Main Methods:

• Employed high-resolution laser photoelectron attachment spectroscopy.
• Investigated electron capture by F2 molecules at very low collision energies.

Main Results:

• Observed a clear p-wave threshold behavior in the cross-section for F- formation from electron capture by F2.
• This result aligns with theoretical models predicting attachment via a p-wave shape resonance.

Conclusions:

• The study confirms that low-energy electron attachment to F2 proceeds through the F2- (2Sigma{u}{+}) p-wave shape resonance.
• The findings contradict earlier experimental claims suggesting s-wave threshold behavior, providing a definitive understanding of the attachment mechanism.