Researchers use gamma rays to detect hidden nuclear threats

Researchers are currently exploring methods to use gamma rays to develop more powerful nuclear detection devices that can penetrate lead or other thick containers.

Gamma rays are the most energetic light wave and are capable of penetrating thick lead shielding, which make them ideal for detecting nuclear materials that have been hidden away or shielded.

Scientists have created “MEGa-rays” by using fast-moving electrons to convert laser photons into the gamma part of the spectrum. These MEGa-rays are then tuned to a specific energy frequency so that they will only react with a certain type of material.

For instance, MEGa-Rays could be set to react only with uranium-235, which is used in nuclear fuel, while passing through less dangerous materials like uranium-238 to avoid false positives.

In addition to detection applications, MEGa-rays could be used to analyze nuclear materials to determine how enriched a spent fuel rod is in uranium-235.

Researchers call this practice “nuclear photonics,” the study of nuclei with light.

“It is kind of like tunable laser absorption spectroscopy but with gamma-rays,” explains Chris Barty of Lawrence Livermore National Laboratory.

So far MEGa-rays have been used to identify elements like lithium and lead hidden behind metal barriers.

Research is still being conducted but scientists believe that the next generation of MEGa-ray devices will be a million times brighter and capable of seeing through thick metal to find specific substances in less than a second.

Practical applications include mounting MEGa-ray detectors on a mobile platform and using it to screen cargo containers for bomb materials or using them in medicine to track drugs that carry specific isotope markers.

Scientists expect that the technology will be developed within the next several years.