Far-Ultraviolet Emission Cross Sections of Ne 2 and Ne 3 Excited by Electron Impact

We have measured the electron-impact-induced fluorescence spectrum of neon in the wavelength range 120-270 nm at a spectral resolution of 0.43 nm (FWHM). The strongest lines observed in the far-ultraviolet (FUV) spectrum of neon are assigned to terms of the doublet system of Ne 2 (2s(sup 2) 2p(sup 4)nl and the triplet system of Ne 3 (2s(sup 2)2p(sup 3)3l). Our FUV spectral data, obtained at 300 eV electron-impact energy, provide absolute emission cross sections of these Ne 2 and Ne 3 lines, and are compared to previous measurements where available. In addition, the excitation function of the strongest Ne II line observed at 191.6 nm was measured from threshold to 1000 eV electron-impact energy.