Luminescence measurements of Xe+ + N2 and Xe2+ + N2 hyperthermal charge transfer collisions

Abstract

Luminescence spectra are recorded for collisions between Xe+/Xe2+ and molecular nitrogen at energies ranging from 4.5 to 316 eV in the center-of-mass frame. In the Xe+ + N2 collision system, evidence for luminescent charge-transfer products is only found through Xe I emission lines. The most intense features of the luminescence spectra are attributed to atomic N emissions observed above ∼20 eV. Intense ${\rm N}_{2}^{+}$N2+ A 2Πu − ${\rm X}\;^{2}\Sigma_{\rm g}^{+}$X2Σg+ and ${\rm B}\;^{2}\Sigma_{\rm u}^{+}$B2Σu+ − ${\rm X}\;^{2}\Sigma_{\rm g}^{+}$X2Σg+ radiance is observed from Xe2+ + N2 collisions. The B state formation cross section decreases with collision energy until 20 eV, after which it becomes independent of impact energy with an approximate value of 3 Å2. The cross section for ${\rm N}_{2}^{+}$N2+ A (v > 0) formation increases with energy until 20 eV, after which it remains nearly constant at ∼1 Å2. The ${\rm N}_{2}^{+}$N2+ product vibrational distributions extracted from the spectra are non-Franck-Condon for both electronic product states at low collision energies. The distributions resemble a Franck-Condon distribution at the highest energies investigated in this work.