Absolute UV and Soft X-ray photoabsorption of ethylene by high resolution dipole (e, e) spectroscopy

Abstract

Abstract Absolute photoabsorption oscillator strengths (cross sections) for the valence shell discrete region of ethylene from 6 to 10.7 eV have been measured using high resolution (∼ 0.05 eV fwhm) dipole (e, e) spectroscopy. A long-range spectrum was also obtained from 6 to 200 eV at low resolution ( ∼ 1 eV fwhm), from which the absolute oscillator strength scale was obtained via valence-shell TRK sum-rule normalization. The presently determined absolute oscillator strengths were found to be more consistent with the (exact) theoretical value of the total S (0) TRK sum-rule than previously published data. In addition, the electric dipole polarizability of ethylene determined from the total S (−2) sum-rule incorporating the presently reported oscillator strengths is in very good agreement with experimentally measured polarizability values.