O2+ Production Coming from CO2 Single-Event Electron Impact

In CO2-rich atmospheres that are always exposed to ionizing radiation (e.g., Venus and Mars), every fragmentation process can significantly impact the inventory of moieties present in these environments. Nevertheless, the production of O2+ ions as a direct result of CO2 fragmentation has never been quantified so far. Since molecular oxygen is considered as a potential trace of living organisms, nonbiotic pathways for its production must be known. In this work, O2+ coming from CO2 fragmentation by electron impact is unambiguously identified and measured in absolute scale.Received 14 October 2023Accepted 20 February 2024DOI:https://doi.org/10.1103/PhysRevLett.132.153002© 2024 American Physical SocietyPhysics Subject Headings (PhySH)