The associative ionization of N(2P) + O(3P)

Area of Science:

• Atmospheric Chemistry
• Chemical Kinetics
• Plasma Physics

Background:

• The N(2P) + O(3P) reaction is significant in atmospheric and plasma environments.
• Previous measurements of N(2P) + O reaction rates have yielded varying results.
• Understanding the reaction mechanism is key to accurate atmospheric modeling.

Purpose of the Study:

• To accurately measure the rate constant for the associative ionization reaction N(2P) + O(3P) → NO+ + e-.
• To elucidate the dominant reaction pathway for N(2P) + O collisions.
• To compare experimental findings with existing literature values.

Main Methods:

• Utilized a flow tube apparatus with a flowing afterglow source.
• Generated nitrogen atoms (N(2P)) via dissociative recombination of nitrogen ions.
• Introduced oxygen atoms and monitored the formation of NO+ ions.

Main Results:

• Determined the rate constant for N(2P) + O(3P) → NO+ + e- to be (8 ± 5) × 10-11 cm3 s-1.
• Observed NO+ formation exclusively attributed to the title reaction.
• The measured rate constant is higher than previously reported disappearance rate constants for N(2P) + O.

Conclusions:

• The N(2P) + O(3P) reaction predominantly proceeds via associative ionization.
• Quenching to the 2D or 4S states of nitrogen atoms are minor reaction channels.
• The findings provide crucial data for atmospheric models and plasma chemistry.