Electron transmission studies of decay channels of molecular resonances

Abstract

Measurements are reported of transmission of energy monochromated electrons of energy 0.1-4eV through oxygen, nitrous oxide, nitric oxide, nitrogen dioxide, carbon dioxide, and benzene. Energy loss spectra are measured, and the zero angle scattering functions for excitation of different vibrational levels are reported. The functions show oscillatory structure due to temporary negative ion states. The function for O₂ is analysed in terms of the compound state theory, yielding O₂^-2 pi _g nuclear separation r_e=1.39AA in disagreement with the photodetachment value r_e=1.34+or-0.01AA (Celotta et al). The causes of this discrepancy are probably significant. The transmission functions for zero energy loss are treated by Fourier analysis, which yields the approximate vibrational energies of the temporary negative ion states of O₂^-, NO^-, NO₂^-, C₆H₆^-. It is possible that a second state of NO₂^- contributes the scattering at energies above 1.1eV.