Cross sections for the production of the N₂⁺(B→X), CO⁺(B→X) and N₂O⁺(A→X) fluorescence by photoionisation

Abstract

The cross sections for the production of the N2+(B 2 Sigma u+ to X 2 Sigma g+), CO+(B 2 Sigma + to X 2 Sigma +) and N2O+(A 2 Sigma + to X 2 Pi ) fluorescence in the 3000-6000 AA region are measured with synchrotron radiation from their fluorescence thresholds to 175 AA. The technique used to correct the second-order effect is described. The present results are compared with previous data. Near 540 AA the cross section for the production of the N2+ fluorescence shows structure at the positions of the Rydberg states converging to the N2+(C 2 Sigma u+) state. The cross section for the production of the CO+ fluorescence shows a broad band with its peak at 400 AA. The cross sections for the production of the N2O+ fluorescence shows structure at the positions of the Rydberg series VI-IX.