The middle ultraviolet-visible spectrum of H2 excited by electron impact G.K. James, J.M. Ajello and W.R. Pryor The electron-impact-excited emission spectrum of H2 has been measured in the wavelength region 175-530 nm at a spectral resolution of 1.7 nm (FWHM). The laboratory spectra are characterized by underlying H2 (a-b) continuum emission, together with many strong lines assigned to the gerade singlet states of H2, and to members of the H Balmer series from dissociative excitation of H2.