ABSOLUTE OSCILLATOR-STRENGTHS FOR PHOTOABSORPTION (6-360 EV) AND IONIC PHOTOFRAGMENTATION (10-80 EV) OF METHANOL

Absolute photoabsorption oscillator strengths (cross sections) for the valence and carbon K shells of CH3OH have been measured using low resolution (1 eV fwhm) dipole (e, e) spectroscopy in the equivalent photon energy range 6-360 eV. The present results are compared with previously published optical measurements obtained using conventional light sources in those limited energy regions where such data are available. In addition, high resolution (0.048 eV fwhm) dipole (e, e) spectroscopy has been used to study the valence shell photoabsorption region in more detail from 5-30 eV. The photoionization efficiency, ionic photofragmentation branching ratios and absolute partial oscillator strengths for molecular and dissociative photoionization have been determined for CH3OH by dipole (e, e + ion) spectroscopy from the first ionization threshold to 80 eV. A consideration of the photoabsorption and photoionization data together with thermochemical data and results from previously published coincidence experiments provides information on the dipole induced breakdown pathways of CH3OH in the photon energy range below 80 eV.