Quantum-state-controlled channel branching in cold Ne(³P₂)+Ar chemi-ionization.

Area of Science:

• Chemical Physics
• Quantum Chemistry
• Reaction Dynamics

Background:

• Complete control over reactant degrees of freedom is essential for understanding chemical reaction mechanisms.
• Chemi-ionization is a fundamental energy-transfer reaction crucial for studying reaction dynamics.

Purpose of the Study:

• To investigate the chemi-ionization reaction between Ne(3P2) and Ar under precisely controlled conditions.
• To explore the influence of collision energy and atomic orientation on reaction outcomes.
• To demonstrate control over the branching ratio of the reaction products.

Main Methods:

• Utilized a merged-beam experimental technique to achieve low collision energies (0.02 K to 1,000 K).
• Employed an external magnetic field to specify the orientation of the excited Ne atom relative to Ar.
• Enabled dynamic reorientation of atoms into favorable configurations for reaction.

Main Results:

• Demonstrated the ability to control the chemi-ionization reaction pathway by tuning collision energy and atomic orientation.
• Showcased manipulation of the branching ratio between different reaction outcomes.
• Observed atomic reorientation at low energies, influencing reaction dynamics.

Conclusions:

• Precise control over reactant degrees of freedom allows for detailed investigation and manipulation of reaction mechanisms.
• Chemi-ionization reactions can be controlled by tuning collision energy and atomic orientation.
• The merged-beam technique provides access to low-energy regimes crucial for understanding reaction dynamics.