Physics Department Seminar University of Alaska Fairbanks

J O U R N A L    C L U B


Measurement of the Average Lifetime of a Muon and Exploration into the Effects of Cosmic Rays on Life in the Space Environment

Vivian Palmer
  University of Alaska Fairbanks



Cosmic rays are high energy particles from across the universe that sometimes collide with our atmosphere, leading to many complex interactions, which can be explained using the Standard Model of Particle Physics. Muons are subatomic particles that decay as they travel through the Earth’s atmosphere into smaller particles. Using a polystyrene scintillator that collected roughly 3,000 individual muon decay times, we calculated a mean muon decay time of 2.19 ± .09 microseconds. In this paper, we also explore cosmic rays and their effect on life in the space environment. First, we explore the relationship between cosmic rays and Earth’s environment. We cover two processes through which galactic cosmic rays may impact cloud formation, which are ion-aerosol clear air mechanism and ion-aerosol near cloud mechanism. Then, we investigate the health implications of galactic cosmic rays, which must be considered prior to space travel, and we consider several experimental methods to mitigate exposure to these particles outside of Earth’s atmosphere. Lastly, we establish cosmic rays in the solar system and beyond and propose potential shielding solutions. The solutions we explore are tracing spacecraft trajectories through the magnetospheres of other planets, hydrogen shielding, and other general practices to limit the time in space exposed to radiation


Friday, 7 October 2022

Globe Room, Elvey Building and on Zoom :