Muography: A novel method of density measurement for mining and surveying

Muography is a rapidly developing geophysical method, that utilises high energy cosmic muon particles to explore the inner structure of large objects, such as volcanoes, pyramids or mountains. Cosmic muons originate from upper atmosphere and have a known, steady, angle dependent flux on the surface. Muons are absorbed as they pass through matter, depending on the density of the material along their trajectories. By comparing the expected and the measured muon flux and using geoinformatic models of the observed area it is possibble to calculate the density distribution inside these structures. Our group at the HUN-REN Wigner RCP focuses on muographic imaging including research, hardware development and geophysical applications. There are several ongoing muographic projects inside European mines. Our measurements were able to confirm known density anomalies in these areas. The method can be applied to a wide variety of problems, such as determining the shape and density of geological formations or ore bodies, the location of caves or fractured zones located up to a few hundred meters underground. The presentation describes the priciples of muography and demonstrates it’s usability with examples from multiple projects.