Making munitions manifest

Trillions of cosmic rays that constantly bombard Earth could help catch smugglers trying to bring nuclear weapons or materials into the United States.

Los Alamos National Laboratory scientists have developed a detector that can see through lead or other heavy shielding in truck trailers or cargo containers to detect uranium, plutonium or other dense materials. Their technique, muon radiography, is far more sensitive than x-rays, with none of the radiation hazards of x-ray or gamma-ray detectors now in use at US borders.

Chris Morris of Los Alamos' Physics Division and Rick Chartrand of the Theoretical Division discussed recent improvements to the technique and their efforts to build a prototype detector recently at the Annual Meeting of the American Association for the Advancement of Science.

The threat

Both 2004 US presidential candidates declared nuclear terrorism the greatest threat facing the United States. National security experts have speculated that detonation of a nuclear weapon or radiological dispersion device on US soil could create global chaos by shutting down trade.