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

Nicholas S Shuman; Thomas M Miller; Shaun G Ard; Albert A Viggiano

doi:10.1063/5.0188483

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

J Chem Phys. 2024 Mar 21;160(11):114309. doi: 10.1063/5.0188483.

Authors

Nicholas S Shuman¹, Thomas M Miller², Shaun G Ard¹, Albert A Viggiano¹

Affiliations

¹ Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, Albuquerque, New Mexico 87117, USA.
² Boston College Institute for Scientific Research, Boston, Massachusetts 02549, USA.

PMID: 38501477
DOI: 10.1063/5.0188483

Abstract

The rate constant of the associative ionization reaction N(2P) + O(3P) → NO+ + e- was measured using a flow tube apparatus. A flowing afterglow source was used to produce an ion/electron plasma containing a mixture of ions, including N2+, N3+, and N4+. Dissociative recombination of these species produced a population of nitrogen atoms, including N(2P). Charged species were rejected from the flow tube using an electrostatic grid, subsequent to which oxygen atoms were introduced, produced either using a discharge of helium and oxygen or via the titration of nitrogen atoms with NO. Only the title reaction can produce the NO+ observed after the introduction of O atoms. The resulting rate constant (8 ± 5 ×10-11 cm3 s-1) is larger than previously reported N(2P) + O disappearance rate constants (∼2 × 10-11 cm3 s-1). The possible errors in this or previous experiments are discussed. It is concluded that the N(2P) + O(3P) reaction proceeds almost entirely by associative ionization, with quenching to the 2D or 4S states as only minor processes.