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arXiv · 2509.09832

A generalized independent atom model approach for net ionization of molecules by multiply-charged heavy-ion impact

Hans Jürgen Lüdde·Marko Horbatsch·Tom Kirchner
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Abstract

The previously applied independent atom model (IAM) for highly charged ion-molecule collisions which implemented the suppression of multiple ionization and capture on the basis of geometric overlaps of cross-sectional areas representing ion-atom cross sections using a pixel counting method (PCM), [Phys. Rev. A {\bf 101}, 062709 (2020)] is extended to incorporate the possibility of multiple collisions within the molecule. This is accomplished on the basis of estimated mean free paths for sequential projectile-atom collisions. The IAM-PCM was demonstrated to be successful in describing proton-molecule collisions, and moderately-charged ion impact at high collision energies. The new model does agree with these results, but has important consequences for highly charged projectiles providing larger cross sections than IAM-PCM, but still well below the simple additivity rule results.

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Hans Jürgen Lüdde, Marko Horbatsch, Tom Kirchner. 2025-09-11. A generalized independent atom model approach for net ionization of molecules by multiply-charged heavy-ion impact. https://doi.org/10.1103/8nst-41jd

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