Effective Solid Angle Model and Monte Carlo Method: Improved Estimations to Measure Cosmic Muon Intensity at Sea Level in All Zenith Angles

TL;DR

This paper introduces an effective solid angle model that improves the accuracy of cosmic muon intensity estimations across all zenith angles, surpassing the traditional cosine-squared model, and enhances muon imaging applications.

Contribution

The paper develops a new solid angle model that provides more accurate estimations of cosmic muon counts than existing models, especially at high zenith angles.

Findings

The new model reduces estimation errors at high zenith angles.

It improves the agreement between simulations and experimental measurements.

The model enhances the reliability of muon imaging techniques.

Abstract

Cosmic muons are highly energetic and penetrative particles and these figures are used for imaging of large and dense objects such as spent nuclear fuels in casks and special nuclear materials in cargo. Cosmic muon intensity depends on the incident angle (zenith angle). The low intensity of cosmic muon requires a long measurement time to acquire statistically meaningful counts. Therefore, high-energy particle simulations e.g., GEANT4, are often used to guide measurement studies. However, the measurable cosmic muon count rate changes upon detector geometry and configuration. Here we develop an effective solid angle model to estimate experimental results more accurately than the simple cosine-squared model. We show that the cosine-squared model has a large error at high zenith angles, whereas our model provides improved estimations at all zenith angles. We anticipate our model will enhance the ability to estimate actual measurable cosmic muon count rates in muon imaging applications by reducing the gap between simulation and measurement results. This will increase the value of modeling results and improve the quality of experiments and applications in muon detection and imaging.