Geant4 Simulation Study of Deep Underground Muons: Vertical Intensity and Angular Distribution

Halil Arslan,Mehmet Bektasoglu

doi:10.1155/2013/391573

Abstract

Underground muon intensities up to 10000 m.w.e. and angular distribution up to 6500 m.w.e. in standard rock have been investigated using Geant4 simulation package. Muons with energies above 100 GeV were distributed from the ground level taking into account the muon charge ratio of~1.3 at sea level. The simulated differential muon intensities are in good agreement with the intensities given in the literature. Furthermore, the simulation results for the integrated intensities are consistent with the experimental data, particularly at depths above 4000 m.w.e., where the simulation gives slightly smaller intensities than the experimental ones. In addition, the simulated exponentnat different underground depths agrees well with the experimental points, especially above~2000 m.w.e.

Highlights

Interaction of the primary cosmic rays with the atmospheric nuclei produces secondary cosmic rays that are able to reach the Earth’s surface
Deep underground muon data are useful for background estimations in the underground areas housing neutrino experiments, and muon intensity measurements at various depths yield information on the electromagnetic processes that reduce the flux [1]
Deep underground muon intensity up to 10000 m.w.e. and angular distribution up to 6500 m.w.e. in standard rock have been investigated using Monte Carlo simulations, and the simulation results have been compared with measurements performed by different groups

Summary

Introduction

Interaction of the primary cosmic rays (mostly protons and alpha particles) with the atmospheric nuclei produces secondary cosmic rays that are able to reach the Earth’s surface. Among the mentioned secondary cosmic rays are muons, which are the most abundant charged particles at sea level. They interact weakly with the media they propagate in and can even penetrate large thicknesses of water, ice, or rock. The intensity of muons incident with a large zenith angle reaching a particular depth is expected to be smaller than that of vertical muons. Deep underground muon intensity up to 10000 m.w.e. and angular distribution up to 6500 m.w.e. in standard rock have been investigated using Monte Carlo simulations, and the simulation results have been compared with measurements performed by different groups. The limit of 10000 m.w.e. was selected due to the reason that for deeper depths neutrino-induced muons start to contribute to the muon intensity dominantly

Simulation

Results and Discussion

Conclusions