Cosmic Ray Interactions in Earth's Atmosphere Studied: Implications for Radiation Dose Estimations

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Research at the Graduate University of Advanced Technology in Kerman, Iran, has investigated the interaction of cosmic rays with Earth's atmosphere, focusing on the production of secondary particles, electromagnetic waves, and their dosimetric implications. The study used the Geant4 toolkit to calculate the deviation of cosmic rays due to Earth's magnetic field, the annual effective dose of secondary particles, and the 14C/12C isotopic ratio.

Key Takeaways:

  • The research demonstrated that electromagnetic waves generated in the atmosphere exhibit an energy spectrum ranging from 0 to 500 MeV, with an estimated annual effective dose at ground level of 2.28E-06 mSv/y.
  • The dose from secondary protons in a human-equivalent phantom was found to be 0.105 mSv/y, approximately 30% of the total dose from cosmic rays (0.33 mSv/y).
  • Analysis of magnetic field effects revealed that heavier particles, such as iron and nickel, experience greater deviations in their trajectories compared to lighter elements like protons and oxygen.
  • 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.
  • The findings highlight the significance of cosmic ray interactions in atmospheric ionization, isotopic composition, and radiation dose estimations.
  • The study involved a team of researchers from the Graduate University of Advanced Technology, including Mohammadreza Rezaie, Mehdi Hassanpour, Yassin Heydarizade, Mohammad Rashed Iqbal Faruque, and Marzieh Hassanpour.

Statistics:

  • 0 to 500 MeV: Energy spectrum of electromagnetic waves generated in the atmosphere.
  • 2.28E-06 mSv/y: Estimated annual effective dose at ground level due to secondary particles.
  • 0.105 mSv/y: Dose from secondary protons in a human-equivalent phantom.
  • 0.33 mSv/y: Total dose from cosmic rays.
  • 0.119: Initial 14C/12C ratio in the upper atmosphere.
  • 1.2E-12: 14C/12C ratio at ground level due to atmospheric mixing and chemical interactions.
  • 30%: Percentage of dose from secondary protons compared to total dose from cosmic rays.

Sources:

  • Production of secondary particles from cosmic ray interactions in the earth's atmosphere: Implications for annual effective dose, 14C/12C ratio, and magnetic field effects. PLOS One, 2025;20(10).
  • Public Library Science, 1160 Battery Street, Ste 100, San Francisco, CA 94111, USA.
  • Graduate University of Advanced Technology, Faculty of Modern Sciences and Technologies, Kerman, Iran.