Enhanced UV emissions in active nitrogen and oxygen

A study of background emissions enhancements in nitrogen afterglows, due to addition of discharged O2, in connection with the reactions {N2 (A3Σu+, υ) + O(3P)}, {O2 (a1Δg) + N(4S)} and {O2 (a1Δg) + N2 (A3Σu+)}

“…Recently it was reported [10][11][12] that enhancements of the background N 2 first positive band system (1pbs) [i.e., N 2 (B 3 Π g → A 3 Σ + u )] emission intensities in a flowing afterglow of active nitrogen, [henceforth called "N 2 (B→A) increases"], were observed in the form of an orange flame visible even to the naked eye with the laboratory lights on. These enhancements occurred when a stream of microwave (mw) discharged O 2 was mixed with a stream of mw discharged nitrogen without a catalyst and at much higher pressures than ever before [10][11][12].…”

“…Recently it was reported [10][11][12] that enhancements of the background N 2 first positive band system (1pbs) [i.e., N 2 (B 3 Π g → A 3 Σ + u )] emission intensities in a flowing afterglow of active nitrogen, [henceforth called "N 2 (B→A) increases"], were observed in the form of an orange flame visible even to the naked eye with the laboratory lights on. These enhancements occurred when a stream of microwave (mw) discharged O 2 was mixed with a stream of mw discharged nitrogen without a catalyst and at much higher pressures than ever before [10][11][12]. The recently studied enhancements, as well as those in previous studies [13,14,15], were uniformly ascribed, in references [10][11][12], to the interaction between excited N 2 , (also described as N * 2 for electronically excited N 2 , and as N ♣ 2 for vibrationally excited N 2 , respectively), and electronically excited O 2 , (also O * 2 ), that led to collisional intersystem crossing into the N 2 (B 3 Πg) state [10].…”

“…None of these studies has taken into account any possible effects of the observed "N 2 (B→A) increases" [10][11][12] on these experimental chemical reaction rate constants. Similar "N 2 (B→A) increases" were reported [13][14] in the 1960s.…”

“…These enhancements occurred when a stream of microwave (mw) discharged O 2 was mixed with a stream of mw discharged nitrogen without a catalyst and at much higher pressures than ever before [10][11][12]. The recently studied enhancements, as well as those in previous studies [13,14,15], were uniformly ascribed, in references [10][11][12], to the interaction between excited N 2 , (also described as N * 2 for electronically excited N 2 , and as N ♣ 2 for vibrationally excited N 2 , respectively), and electronically excited O 2 , (also O * 2 ), that led to collisional intersystem crossing into the N 2 (B 3 Πg) state [10]. On the basis of the available evidence, the N 2 (A 3 Σu + ) state was explicitly included [10,12], contrary to its specific exclusion [5].…”

“…Because of the great significance of active nitrogen and oxygen for natural processes and various applications on Earth and in space, many investigations of these systems have been performed [1][2][3][4][5][6][7][8][9][10][11][12]. Recently it was reported [10][11][12] that enhancements of the background N 2 first positive band system (1pbs) [i.e., N 2 (B 3 Π g → A 3 Σ + u )] emission intensities in a flowing afterglow of active nitrogen, [henceforth called "N 2 (B→A) increases"], were observed in the form of an orange flame visible even to the naked eye with the laboratory lights on.…”