Modeling high-energy cosmic ray induced terrestrial muon flux: A lookup table

TL;DR

This paper introduces a lookup table to accurately model terrestrial muon flux caused by high-energy cosmic rays, enabling quantification of radiation dose impacts on Earth from various astrophysical sources over geological timescales.

Contribution

The authors developed a comprehensive lookup table for modeling muon flux from high-energy cosmic rays, facilitating radiation dose calculations for different astrophysical scenarios.

Findings

The lookup table accurately models muon flux for cosmic rays from 10 GeV to 1 PeV.

It enables estimation of radiation doses from cosmic ray events on Earth's surface.

The tool can be used to assess biospheric impacts of astrophysical phenomena.

Abstract

On geological timescales, the Earth is likely to be exposed to an increased flux of high energy cosmic rays (HECRs) from astrophysical sources such as nearby supernovae, gamma ray bursts or by galactic shocks. Typical cosmic ray energies may be much higher than the ~ 1 GeV flux which normally dominates. These high-energy particles strike the Earth's atmosphere initiating an extensive air shower. As the air shower propagates deeper, it ionizes the atmosphere by producing charged secondary particles. Secondary particles such as muons and thermal neutrons produced as a result of nuclear interactions are able to reach the ground, enhancing the radiation dose. Muons contribute 85% to the radiation dose from cosmic rays. This enhanced dose could be potentially harmful to the biosphere. This mechanism has been discussed extensively in literature but has never been quantified. Here, we have developed a lookup table that can be used to quantify this effect by modeling terrestrial muon flux from any arbitrary cosmic ray spectra with 10 GeV - 1 PeV primaries. This will enable us to compute the radiation dose on terrestrial planetary surfaces from a number of astrophysical sources.