Speaker
Description
Muography is a technique that uses cosmic-ray muons to probe the internal structure of objects. Muons are elementary particles that are naturally produced at high energy by the interaction of cosmic rays with the Earth's atmosphere. Two imaging methods, respectively based on the absorption and scattering of muons, have been developed to exploit cosmic-ray muons in a wide range of applications such as volcanology, archaeology, mining, nuclear waste investigations, and material identification surveys. In this study, we focused on the effect of magnetic fields on scanning systems based on scattering muography, where muons can penetrate steel up to 100 cm thick and detect any shielded high-z material. We used the PHITS Monte Carlo code, which is a powerful tool for the simulation of the passage of particles through matter and can also be used to implement various magnetic fields. Cosmic-ray muons have been generated based on the PARMA model. The inspection system used in this study consisted of two 3 m x 6 m detector sets placed above and below the region of interest to be capable of scanning a cargo container in several minutes. The main challenge in systems based on multiple scattering of muons is to estimate the scattering angle and position of the target by reconstructing muon tracks. We used the Point of Closest Approach (POCA) reconstruction algorithm to obtain the muography images of the objects in the inspection area. We then placed a simple dipole magnetic field in the inspection area to investigate how the magnetic field affects the muography images. Results from the study quantify the blurring effect on the obtained image, depending on the strength of the magnetic flux density and the density of the material.
