Using Cosmic Rays to See Inside Materials

At Oak Ridge National Laboratory (ORNL), a mobile muon-tomography system leverages naturally occurring cosmic-ray muons that pass through dense materials and strike scintillators, triggering photons that are captured via wavelength-shifting fibers and routed to photodetectors. Those digitized signals are then processed and reconstructed into high-resolution internal images—enabling new capabilities for spent-fuel monitoring and quantum-materials research.