"Ionization Cross Sections Of Oxygen And Water Molecules For Modeling Electron-Induced Processes In Environmental And Astrophysical Media"

Abstract

In this study, we present a theoretical evaluation of ionization cross sections for diatomic oxygen (O₂) and water (H₂O) molecules under electron impact using the Complex Scattering Potential–Ionization Contribution (CSP-ic) method, refined here as the Improved CSP-ic (ICSP-ic) approach. The ICSP-ic model offers a semi-empirical framework grounded in scattering theory to estimate total ionization cross sections, especially useful in the absence of extensive experimental data or for extending known data to higher energy ranges.

Calculations have been performed over a broad energy range (e.g., 10–2000 eV), covering the ionization threshold to well beyond the peak cross-section region. The obtained cross-section values are compared with available experimental data and existing theoretical models for validation. Our results show good agreement with known data and demonstrate the capability of the ICSP-ic method to reliably predict ionization behavior of small polyatomic and diatomic systems under electron impact.

The insights from this study contribute to the growing database of cross sections critical for modeling atmospheric, astrophysical, and plasma environments where electron-molecule interactions play a pivotal role.