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

Abstract

Abstract Absolute photoabsorption oscillator strengths (cross sections) for the discrete electronic transitions of acetylene from 5.5 to 11.2 eV have been measured using high resolution ≈0.05 eV FWHM) dipole (e,e) spectroscopy. This experimental resolution enabled absolute oscillator strengths for most of the individual vibronic transitions to be obtained. A broader range spectrum, obtained from 5.5 to 200 eV at a resolution of ≈1 eV FWHM, was used to establish to absolute oscillator strength scale via TRK sum-rule normalization. The absolute oscillator strengths for the Rydberg transitions are in many cases significantly higher than previously reported values obtained using direct optical photoabsorption methods.