Theoretical partial ionization cross sections by electron impact for production of cations from CH3OH, CO2 and NH3

Abstract

In the present article, the Plane Wave Born Approximation (PWBA) along with Generalised Oscillator Strength (GOS) proposed by Weizsacker-Williams has been employed to calculate the partial ionization cross sections due to electron impact for production of cations (CH3OH+, CH2OH+, CH2O+, CH3+, CH2+ CHO+, CH+, C+, CO+, OH+, H2+ and H+) from methanol, for production of cations (CO2+, CO+, O+ and C+) from carbon dioxide and for production of cations (NH3+, NH2+, NH+, N+ and H+) from ammonia from the ionization threshold to 1 keV. The use of GOS given by Weizsacker-Williams breaks the expression of cross section into two terms, Bethe cross section and Mott cross section. Both terms depend on Optical Oscillator Strength (OOS). Furthermore, binary encounter theory has also been used. By summing all the partial ionization cross sections, total ionization cross sections are also obtained. The calculated cross sections are compared with the previously available experimental data and theoretical cross sections. The present calculations are found in remarkable agreement with available experimental data and other previous theoretical results.