Vacuum-Ultraviolet Excitation Cross Sections by Electron Impact on NO

Abstract

Absolute excitation functions were measured for the NO+ A 1Π −X 1Σ+ molecular band system, the nitrogen 1200–, 1243–, and 1493–Å multiplets, and oxygen 1304–Å multiplet. Excitation was by electron impact on NO from threshold to ·250 eV. At 100 eV the excitation cross section for the NO+ A—X system is 9.7 × 10–18 cm2 while the cross sections for the nitrogen and oxygen multiplets are: N, 1200 Å − 4.8 × 10–18 cm2; N, 1243 Å–0.89 × 10–18 cm2; N, 1493 Å–1.5× 10–18 cm2; and O, 1304 Å–1.1× 10–18 cm2. From the vibrational intensity distribution of the A—X system, the variation of electronic transition moment with r centroid was determined and this result used to calculate an array of vibrational transition probabilities. In addition, cross sections were measured at 100 eV only for the N 1135–, N 1745–, O 1152–, and O 1218–Å multiplets. Cross sections for these multiplets are: N, 1135 Å – 1.6× 10–18 cm2; N, 1745 Å–0.87× 10–18 cm2; O, 1152 Å–0.85× 10–18 cm2; and O, 1218 Å–0.39× 10–18 cm2.