Absolute cross sections and kinetic energy release for doubly and triply charged fragments produced by electron impact on CO+

摘要

Absolute cross sections for electron impact ionization of CO+ leading to the formation of doubly and triply charged products (CO2+, C2+ and O2+, C3+ and O3+) are reported in the energy range from their respective thresholds to 2500 eV. Around the maximum, cross section values are found to be ( 13.36 +/- 0.56) x 10(-18) cm(2), ( 5.58 +/- 0.55) x 10(-18) cm(2) and (1.37 +/- 0.14) x 10(-18) cm(2) for CO2+, C2+ and O2+, respectively, and (28.3 +/- 7.0) x 10(-21) cm(2) and (2.4 +/- 0.7) x 10(-21) cm(2) for C3+ and O3+, respectively. The analysis of ionic product velocity distributions, obtained by means of a crossed electron-ion beam set-up, allows the determination of the kinetic energy release distributions. They are seen to extend from 0 to 50 eV both for C2+ and O2+. The mean kinetic energy releases for C3+ and O3+ are found to be 33 +/- 5 eV and 39 +/- 9 eV, respectively. The cross sections are seen to depend exponentially on the potential energy of each dissociated ion pair. The total single CO+ ionization cross section calculated by application of the Deutsch-Mark ( DM) formalism is found to be in good agreement with the experimental results.