Ionization of CF<sub>3</sub>CH<sub>2</sub>F by Protons and Photons

(1) Background: Ionizing radiation in the Earth’s atmosphere drives key chemical transformations affecting atmospheric composition. Despite their environmental relevance, experimental data on proton collisions with hydrofluorocarbons remain limited, and theoretical models for total cross-sections an...

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Main Authors: Carlos E. Ferreira, Jorge A. de Souza-Corrêa, Alexandre B. Rocha, Antônio C. F. Santos
Format: Article
Language:English
Published: MDPI AG 2025-06-01
Series:Atoms
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Online Access:https://www.mdpi.com/2218-2004/13/6/58
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author Carlos E. Ferreira
Jorge A. de Souza-Corrêa
Alexandre B. Rocha
Antônio C. F. Santos
author_facet Carlos E. Ferreira
Jorge A. de Souza-Corrêa
Alexandre B. Rocha
Antônio C. F. Santos
author_sort Carlos E. Ferreira
collection DOAJ
description (1) Background: Ionizing radiation in the Earth’s atmosphere drives key chemical transformations affecting atmospheric composition. Despite their environmental relevance, experimental data on proton collisions with hydrofluorocarbons remain limited, and theoretical models for total cross-sections and stopping power are still underdeveloped. (2) Methods: This study applies Rudd’s semiempirical model to calculate proton impact ionization cross-sections for the CF<sub>3</sub>CH<sub>2</sub>F molecule, considering contributions from both outer and inner electron shells. The model enables the estimation of differential cross-sections and the average energy of secondary electrons. In addition, we calculate the photoionization cross-sections using a discretized representation of the continuum—the so-called pseudo-spectrum—obtained through TDDFT with PBE0 as an exchange–correlation functional and compare it with the cross-section obtained for proton impact in the high-energy limit. (3) Results: The Rudd model proves highly adaptable and suitable for numerical applications. However, its validation is hindered by the scarcity of experimental data. Existing models, such as SRIM and Bethe–Bloch, show significant discrepancies due to their limited applicability at intermediate energies and lack of molecular structure consideration. (4) Conclusions: A comparison between the Rudd and BEB models reveals strong agreement in the analyzed energy range. This consistency stems from both models accounting for the molecular structure of the target, as well as from the fact that protons and electrons possess charges of the same magnitude, supporting a coherent description of ionization processes at these energies.
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spelling doaj-art-ebe53252f2484062bf983fd6efde65082025-08-20T03:32:27ZengMDPI AGAtoms2218-20042025-06-011365810.3390/atoms13060058Ionization of CF<sub>3</sub>CH<sub>2</sub>F by Protons and PhotonsCarlos E. Ferreira0Jorge A. de Souza-Corrêa1Alexandre B. Rocha2Antônio C. F. Santos3Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-909, BrazilInstituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-909, BrazilInstituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-909, BrazilInstituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-909, Brazil(1) Background: Ionizing radiation in the Earth’s atmosphere drives key chemical transformations affecting atmospheric composition. Despite their environmental relevance, experimental data on proton collisions with hydrofluorocarbons remain limited, and theoretical models for total cross-sections and stopping power are still underdeveloped. (2) Methods: This study applies Rudd’s semiempirical model to calculate proton impact ionization cross-sections for the CF<sub>3</sub>CH<sub>2</sub>F molecule, considering contributions from both outer and inner electron shells. The model enables the estimation of differential cross-sections and the average energy of secondary electrons. In addition, we calculate the photoionization cross-sections using a discretized representation of the continuum—the so-called pseudo-spectrum—obtained through TDDFT with PBE0 as an exchange–correlation functional and compare it with the cross-section obtained for proton impact in the high-energy limit. (3) Results: The Rudd model proves highly adaptable and suitable for numerical applications. However, its validation is hindered by the scarcity of experimental data. Existing models, such as SRIM and Bethe–Bloch, show significant discrepancies due to their limited applicability at intermediate energies and lack of molecular structure consideration. (4) Conclusions: A comparison between the Rudd and BEB models reveals strong agreement in the analyzed energy range. This consistency stems from both models accounting for the molecular structure of the target, as well as from the fact that protons and electrons possess charges of the same magnitude, supporting a coherent description of ionization processes at these energies.https://www.mdpi.com/2218-2004/13/6/58ionizationrefrigerantstopping power
spellingShingle Carlos E. Ferreira
Jorge A. de Souza-Corrêa
Alexandre B. Rocha
Antônio C. F. Santos
Ionization of CF<sub>3</sub>CH<sub>2</sub>F by Protons and Photons
Atoms
ionization
refrigerant
stopping power
title Ionization of CF<sub>3</sub>CH<sub>2</sub>F by Protons and Photons
title_full Ionization of CF<sub>3</sub>CH<sub>2</sub>F by Protons and Photons
title_fullStr Ionization of CF<sub>3</sub>CH<sub>2</sub>F by Protons and Photons
title_full_unstemmed Ionization of CF<sub>3</sub>CH<sub>2</sub>F by Protons and Photons
title_short Ionization of CF<sub>3</sub>CH<sub>2</sub>F by Protons and Photons
title_sort ionization of cf sub 3 sub ch sub 2 sub f by protons and photons
topic ionization
refrigerant
stopping power
url https://www.mdpi.com/2218-2004/13/6/58
work_keys_str_mv AT carloseferreira ionizationofcfsub3subchsub2subfbyprotonsandphotons
AT jorgeadesouzacorrea ionizationofcfsub3subchsub2subfbyprotonsandphotons
AT alexandrebrocha ionizationofcfsub3subchsub2subfbyprotonsandphotons
AT antoniocfsantos ionizationofcfsub3subchsub2subfbyprotonsandphotons