A new calculation method for the free electron fraction of an ionization chamber in the ultra-high-dose-per-pulse regimen
| العنوان: | A new calculation method for the free electron fraction of an ionization chamber in the ultra-high-dose-per-pulse regimen |
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| المؤلفون: | Fabio Di Martino, Damiano Del Sarto, Salvatore Barone, Maria Giuseppina Bisogni, Simone Capaccioli, Federica Galante, Alessia Gasparini, Giulia Mariani, Luigi Masturzo, Marco Montefiori, Matteo Pacitti, Fabiola Paiar, Jake Harold Pensavalle, Francesco Romano, Stefano Ursino, Verdi Vanreusel, Dirk Verellen, Giuseppe Felici |
| المصدر: | Physica medica |
| سنة النشر: | 2022 |
| مصطلحات موضوعية: | Computer. Automation, Biophysics, General Physics and Astronomy, Radiology, Nuclear Medicine and imaging, Electrons, General Medicine, Human medicine, Particle Accelerators, Radiometry |
| الوصف: | The free electron fraction is the fraction of electrons, produced inside the cavity of an ionization chamber after irradiation, which does not bind to gas molecules and thereby reaches the electrode as free electrons. It is a fundamental quantity to describe the recombination processes of an ionization chamber, as it generates a gap of positive charges compared to negative ones, which certainly will not undergo recombination.The free electron fraction depends on the specific chamber geometry, the polarizing applied voltage and the gas thermodynamic properties. Therefore, it is necessary to evaluate such fraction in an accurate and easy way for any measurement condition.In this paper, a simple and direct method for evaluating the free electron fraction of ionization chambers is proposed.We first model the capture process of the electrons produced inside an ionization chamber after the beam pulse; then we present a method to evaluate the free electron fraction based on simple measurements of collected charge, by varying the applied voltage. Finally, the results obtained using an Advanced Markus chamber irra-diated with a Flash Radiotherapy dedicated research Linac (ElectronFlash) to estimate the free electron fraction are presented.The proposed method allows the use of a conventional ionization chamber for measurements in ultra-high -dose -per-pulse (UHDP) conditions, up to values of dose -per-pulse at which the perturbation of the electric field due to the generated charge can be considered negligible. |
| تدمد: | 1724-191X 1120-1797 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b417598ebe1ee9682e57a10f3328cd25 https://pubmed.ncbi.nlm.nih.gov/36370686 |
| حقوق: | CLOSED |
| رقم الأكسشن: | edsair.doi.dedup.....b417598ebe1ee9682e57a10f3328cd25 |
| قاعدة البيانات: | OpenAIRE |
Full Text via ClinicalKey | تدمد: | 1724191X 11201797 |
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