Academic Journal
Monte Carlo study of air ionization by X-ray photons and backscattering under diagnostic conditions using the developed Irradose code.
| Title: | Monte Carlo study of air ionization by X-ray photons and backscattering under diagnostic conditions using the developed Irradose code. |
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| Authors: | El Basraoui O; Laboratory of Condensed Matter and Interdisciplinary Sciences, Mohammed V University in Rabat, Rabat, Morocco., Qassimi O; Laboratory of Condensed Matter and Interdisciplinary Sciences, Mohammed V University in Rabat, Rabat, Morocco., Yahyaoui C; Laboratory of Condensed Matter and Interdisciplinary Sciences, Mohammed V University in Rabat, Rabat, Morocco., El Amri L; Laboratory of Condensed Matter and Interdisciplinary Sciences, Mohammed V University in Rabat, Rabat, Morocco., Tahiri N; Laboratory of Condensed Matter and Interdisciplinary Sciences, Mohammed V University in Rabat, Rabat, Morocco., El Bounagui O; Laboratory of Condensed Matter and Interdisciplinary Sciences, Mohammed V University in Rabat, Rabat, Morocco. elbounagui@gmail.com. |
| Source: | Radiological physics and technology [Radiol Phys Technol] 2026 Sep; Vol. 19 (3), pp. 1141-1152. Date of Electronic Publication: 2026 Jul 13. |
| Publication Type: | Journal Article |
| Language: | English |
| Journal Info: | Publisher: Springer Japan Country of Publication: Japan NLM ID: 101467995 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1865-0341 (Electronic) Linking ISSN: 18650333 NLM ISO Abbreviation: Radiol Phys Technol Subsets: MEDLINE |
| Imprint Name(s): | Original Publication: Tokyo : Springer Japan |
| MeSH Terms: | Monte Carlo Method* , Photons* , Scattering, Radiation* , Air* , Air Ionization*, Phantoms, Imaging ; X-Rays |
| Abstract: | Irradiation of air by X-rays, particularly during diagnostic and medical imaging procedures, induces a temporary ionization of its constituents and may lead to the formation of reactive species such as O₂+, O₂- and O₂2⁻. This study analyzes photon transport as well as scattering and backscattering phenomena in air and tissue-equivalent media, in order to evaluate dose, energy, and angular distributions. A Monte Carlo code named Irradose has been developed to simulate these processes in cylindrical geometries containing air, an HCNO phantom representing the patient, and an aqueous medium. The model was validated by comparison with the PHITS and Geant4 codes, showing good agreement with deviations below 5%. The results highlight a progressive attenuation of the beam dose in air between the source and the phantom, estimated at 1.2%. They also show a higher dose deposition in the HCNO phantom. Backscatter from this medium contributes significantly to the secondary photon field in air, with a maximum of 14.62% at 0.15 MeV and a dominant angular distribution around 2.4 rad. The ionic species O₂+, O₂- and O₂2- are discussed, as well as the limitations of this work and the associated perspectives. (© 2026. The Author(s), under exclusive licence to Japanese Society of Radiological Technology and Japan Society of Medical Physics.) |
| Competing Interests: | Declarations. Conflicts of interest: The authors declare that they have no conflict of interest. Ethics approval: This study is based on numerical simulations and computational modeling of X-ray–induced air ionization under clinical radiological conditions. No human subjects, biological samples, or direct clinical interventions were involved. Therefore, ethical approval was not required. Informed consent: This study did not involve human participants or patient-specific clinical data. Therefore, informed consent was not required. |
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| Contributed Indexing: | Keywords: Air ionization; Backscatter flux; HCNO phantom; Monte Carlo simulation; Radiation transport |
| Entry Date(s): | Date Created: 20260713 Date Completed: 20260905 Latest Revision: 20261008 |
| Update Code: | 20261008 |
| DOI: | 10.1007/s12194-026-01094-2 |
| PMID: | 42440061 |
| Database: | MEDLINE |
| ISSN: | 1865-0341 |
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| DOI: | 10.1007/s12194-026-01094-2 |