Tehran University of Medical Sciences Basic & Clinical Cancer Research 2228-6527 13 3 2022 08 14 210 224 Nasrin Niknam Department of Physics, Shiraz Branch, Islamic Azad University, Shiraz, Iran Seyedeh Nasrin Hosseinimotlagh Department of Physics, Shiraz Branch, Islamic Azad University, Shiraz, Iran Zohreh Parang Department of Physics, Shiraz Branch, Islamic Azad University, Shiraz, Iran 2021 09 07 2022 04 11 Fluorine 18-deoxyglucose (18FDG) is often used in Positron Emission Tomography (PET). PET imaging is one of the useful tool which is used to cancer detection and management. PET growth is limited due to problems that depend on the production of Fluorine-18.Imaging results are strongly dependent on the information of nuclear reaction cross section data. This study is done to calculate the stopping power, RCSDA, simulated and distributed absorbed dose of F-18, in water. In order to access these goals, we use the Geant4/Gate simulation and the Bethe-Bloch theory model. The results of this simulation and this theory model are in good agreement with each other .The main point of this paper is the presentation of a theoretical approach to the production of Fluorine-18 by using protons production through the main nuclear fusion reaction and the side fusion reaction   uses helium-3 as a catalyzed. https://bccr.tums.ac.ir/index.php/bccrj/article/view/399