QUANTITATIVE STUDIES OF THE PHOTOABSORPTION (4.5-488 EV) AND PHOTOIONIZATION (9-59.5 EV) OF METHYL-IODIDE USING DIPOLE ELECTRON-IMPACT TECHNIQUES

Absolute oscillator strengths (cross sections) for the valence shell, I 4d, 4p, 4s and C Is inner shell photoabsorption of CH3I have been me asured using low resolution(l eV fwhm) dipole (e,e) spectroscopy in th e equivalent photon energy range from 4.5 to 488 eV. In addition, high resolution (0.05-0.1 eV fwhm) dipole (e,e) spectroscopy has been used to study the absolute valence shell and I 4d inner shell photoabsorpt ion spectra of CH3I from 4 to 65 eV in mon detail. The photoionization efficiency, ionic photofragmentation branching ratios and absolute pa rtial oscillator strengths for molecular and dissociative photoionizat ion have been determined for CH3I by dipole (e,e + ion) spectroscopy f rom the first ionization threshold to 59.5 eV. The major pathways of t he ionic dipole induced breakdown scheme have been predicted from thes e results. Estimates of the absolute electronic state partial oscillat or strengths of CH3I+ from photoionization of CH3I were derived from t he dipole induced breakdown scheme and the molecular and dissociative photoionization partial oscillator strengths. (C) 1998 Elsevier Scienc e B.V. All rights reserved.