cosmic rays catch concealed nukes

With the fear of terrorists using dirty bombs increasing, screening for smuggled nuclear materials has become more important than ever. Physicists from the Los Alamos National Laboratory in New Mexico have invented a device that uses cosmic rays to detect dense materials such as plutonium and uranium, they report in the March 20 Nature. As cosmic rays pass through Earth’s atmosphere, they generate highly penetrating subatomic particles called muons. The researchers have built a detector that can trace the path of the muons as they pass through dense material. The detector uses a computer to gather the information and generate an image. According to the report, the detector could reveal the outline of a block of uranium concealed inside a truck full of sheep. The researchers say their method is harmless and inexpensive compared to X-rays, and could be suitable for scanning trucks and cars for nuclear materials at border crossings.

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 3/25/2003.