The middle ultraviolet-visible spectrum of H2 excited by electron impact

Abstract

The electron-impact-induced emission spectrum of H2 has been measured in the extended wavelength region 175-530 nm at a spectral resolution of 1.7 nm (full width at half maximum). The laboratory spectra observed in the middle ultraviolet (MUV) and visible spectral region are characterized by underlying H2(a 3∑+g → b 3∑+u) continuum emission, together with many strong lines assigned to the radiative decay of the gerade singlet states of H2, to members of the H Balmer series resulting from dissociative excitation of H2. Our calibrated MUV spectral data, obtained at 14, 19, and 100 eV electron-impact energies, provide absolute emission cross sections of these H2 lines and will assist in the interpretation of planned Galileo ultraviolet spectrometer observations of Jupiter's aurora in this wavelength region. Copyright 1998 by the American Geophysical Union.