Cosmic ray muon radiography

Highly penetrating cosmic ray muons shower the Earth at the rate of 10,000 per square meter per minute at sea level. A novel technique has been developed at Los Alamos National Laboratory which exploits the multiple Coulomb scattering of these particles for nondestructive inspection without the use of artificial radiation. In this work the concept of and theory behind cosmic ray muon radiography are described. An analysis of the information carried by scattered muons is presented, and a framework for estimating the Z-level of material by measuring muon scattering is outlined. An experimental prototype was constructed to validate these concepts, and proof of principle based on experimental data is provided. A new iterative tomographic reconstruction algorithm was developed based on maximum likelihood principles. The MLSD (Maximum Likelihood Scattering and Displacement) Algorithm for cosmic ray muon radiography is presented and illustrated through simulated examples.