text: Muon tomography is a technique that uses cosmic ray muons to generate three-dimensional images of volumes using information contained in the Coulomb scattering of the muons. Since muons are much more deeply penetrating than X-rays, muon tomography can be used to image through much thicker material than x-ray based tomography such as CT scanning. The muon flux at the Earth's surface is such that a single muon passes through a volume the size of a human hand per second.
  Muon imaging was originally proposed and demonstrated by Alvarez. The method was re-discovered and improved upon by a research team at Los Alamos National Laboratory, muon tomography is completely passive, exploiting naturally occurring cosmic radiation. This makes the technology ideal for high throughput scanning of volume material where operators are present, such as at a marine cargo terminal. In these cases, truck drivers and customs personnel do not have to leave the vehicle or exit an exclusion zone during scanning, expediting cargo throughput.
  Multi-mode passive detection systems (MMPDS), based upon muon tomography, are currently in use by Decision Sciences International Corporation at Freeport, Bahamas, and the Atomic Weapons Establishment in the United Kingdom. An MMPDS system has also been contracted by Toshiba to determine the location and the condition of the nuclear fuel in the Fukushima Daiichi Nuclear Power Plant.