OICC Press Journal of Theoretical and Applied Physics 2251-7235 18 4 2024 08 30 Effect of Gas Pressure on Plasma Characteristics of a 2.45 GHz ECR Ion Source 10.57647/j.jtap.2024.1804.52 EN Marzieh Asadi Aghbolaghi Department of Radiation Application, Faculty of Nuclear Engineering, Shahid Beheshti University, Tehran, Iran 0009-0009-0342-7118 Fereydoun Abbasi Davani Department of Radiation Application, Faculty of Nuclear Engineering, Shahid Beheshti University, Tehran, Iran 0000-0002-3175-3449 Masoomeh Yarmohammadi Satri Physic and Accelerators Research School, Nuclear Science and Technology Research Institute, Tehran, Iran Zafar Riazi Mobaraki Physic and Accelerators Research School, Nuclear Science and Technology Research Institute, Tehran, Iran Farshad Ghasemi Physic and Accelerators Research School, Nuclear Science and Technology Research Institute, Tehran, Iran Journal Article 2024 08 30 Electron cyclotron resonance ion source (ECRIS) is designed and simulated using COMSOL software. The 2.45 GHz microwave is injected through a coaxial cable into a cylindrical chamber with a diameter of 9 cm and a length of 10 cm. Two coils are employed to produce a flat-B magnetic field profile and two resonance zones on both sides of the chamber. Hydrogen gas plasma is simulated by considering H2, H2+ and H3+ ions, and H and H2 as neutrals. Finally, electron density and temperature are reported as a function of gas pressure. It is observed that as the gas pressure increases, the electron temperature decreases and the electron density decline following an initial increases.