New materials to detect radiation may lead to a handheld device for detecting nuclear weapons or materials such as a "bomb in a suitcase," U.S. researchers say.

"The terrorist attacks of 9/11 heightened interest in this area of security, but the problem remains a real challenge," Northwestern University chemistry Professor Mercouri G. Kanatzidis said in a release issued by the school Monday.

"We have designed promising semiconductor materials that, once optimized, could be a fast, effective and inexpensive method for detecting dangerous materials such as plutonium and uranium."

The researchers developed new semiconductor materials from heavy elements that, when struck by gamma rays from a suspect material, emit electrons.

Because every element has a particular spectrum, the signal of the detected electron emissions identifies the suspect material.

One hurdle for the researchers is that most heavy metals have a lot of mobile electrons, so electrons excited by gamma radiation are hard to detect.

"It's like having a bucket of water and adding one drop -- the change is negligible," Kanatzidis explained. "We needed a heavy element material without a lot of electrons. This doesn't exist naturally so we had to design a new material."

They developed two new semiconductor materials, cesium-mercury-sulfide and cesium-mercury-selenide.

"Our materials are very promising and competitive," Kanatzidis said. "With further development, they should outperform existing hard radiation detector materials."

Related Links
Learn about nuclear weapons doctrine and defense at SpaceWar.com
Learn about missile defense at SpaceWar.com
All about missiles at SpaceWar.com
Learn about the Superpowers of the 21st Century at SpaceWar.com

Tweet