Emission Cross Sections of CO by Electron Impact in the Interval 1260–5000 Å. I

Abstract

Emission cross sections and band emission probabilities have been measured for the fourth positive system ${\mathrm{(A}}^1{\mathrm{\Pi \to X}}^1{\Sigma }^{+})$ and the Cameron system ${\mathrm{(a}}^3{\mathrm{\Pi \to X}}^1{\Sigma }^{+})$ of CO and the first negative system ${\mathrm{(B}}^2{\Sigma }^{+}{\mathrm{\to \; X}}^2{\Sigma }^{+})$ and the comet tail system ${\mathrm{(A}}^2{\mathrm{\Pi \to X}}^2{\Sigma }^{+})$ of CO⁺ by electron beam excitation of CO from threshold to 300 eV. Excitation cross sections have been measured for CI, CII, and OI multiplets produced by dissociative excitation of CO. A comparison of the measured emission probabilities with theoretical values based on Franck—Condon factors for direct excitation was made. Molecular branching ratios were used to extend the optical calibration from the blackbody region to the vacuum ultraviolet.