Science: A new technique to scan equipment for problems or to look for nuclear material and other contraband uses the scattering of muons created when cosmic rays collide with molecules in Earth’s upper atmosphere. Able to penetrate matter more deeply than some other particles, muons have been used to image concrete degradation, valve conditions, and pipe-wall thickness at nuclear plants, according to a study published in AIP Advances. Imaging muons requires two sets of detectors to map the muons' trajectories before and after they pass through the object being studied. The denser the object, the more the muons are deflected. That information is then used to create a three-dimensional image of the mass distribution. Because muon radiation is ubiquitous on Earth and nonharmful to humans, muon tomography poses fewer problems and requires fewer safety measures than x-ray imaging. However, it takes longer to create an image, so it is better suited for routine inspections and monitoring.
