Abstract
This study investigates the interaction of cosmic rays with Earth's atmosphere, focusing on the production of secondary particles, electromagnetic waves, and their dosimetric implications. Using the Geant4 toolkit, the deviation of cosmic rays due to Earth's magnetic field, the annual effective dose of secondary particles, and the 14C/12C isotopic ratio were calculated. The results demonstrate that electromagnetic waves generated in the atmosphere exhibit an energy spectrum ranging from 0 to 500 MeV. The estimated annual effective dose at ground level is 2.28E-06 mSv/y, while the dose from secondary protons in a human-equivalent phantom is 0.105 mSv/y, approximately 30% of the total dose from cosmic rays (0.33 mSv/y). Analysis of magnetic field effects reveals that heavier particles, such as iron and nickel, experience greater deviations in their trajectories compared to lighter elements like protons and oxygen. Furthermore, the initial 14C/12C ratio in the upper atmosphere was calculated as 0.119, which decreases to 1.2E-12 at ground level due to atmospheric mixing and chemical interactions. These findings highlight the significance of cosmic ray interactions in atmospheric ionization, isotopic composition, and radiation dose estimations.