Nuclear terrorismNovel radiation detection technology to thwart nuclear terrorism
Researchers at the Georgia Tech Research Institute (GTRI) are developing ways to enhance the radiation-detection devices used at ports, border crossings, airports, and elsewhere; the aim is to create technologies that will increase the effectiveness and reliability of detectors in the field, while also reducing cost
Among terrorism scenarios that raise the most concern are attacks involving nuclear devices or materials. For this reason, technology that can effectively detect smuggled radioactive materials is considered vital to U.S. security.
Researchers at the Georgia Tech Research Institute (GTRI) are developing ways to enhance the radiation-detection devices used at ports, border crossings, airports, and elsewhere. The aim is to create technologies that will increase the effectiveness and reliability of detectors in the field, while also reducing cost. The work is co-sponsored by the Domestic Nuclear Defense Office (DNDO) of the Department of Homeland Security and by the National Science Foundation.
“U.S. security personnel have to be on guard against two types of nuclear attack — true nuclear bombs, and devices that seek to harm people by dispersing radioactive material,” said Bernd Kahn, a researcher who is principal investigator on the project. “Both of these threats can be successfully detected by the right technology.”
A Georgia Tech release reports that the GTRI team, led by co-principal investigator Brent Wagner, is utilizing novel materials and nanotechnology techniques to produce improved radiation detection. The researchers have developed the Nano-photonic Composite Scintillation Detector, a prototype that combines rare-earth elements and other materials at the nanoscale for improved sensitivity, accuracy and robustness.
Details of the research were presented 23 April 2012 at the SPIE Defense, Security, and Sensing Conference held in Baltimore, Maryland.
Scintillation detectors and solid-state detectors are two common types of radiation detectors, Wagner explained. A scintillation detector commonly employs a single crystal of sodium iodide or a similar material, while a solid-state detector is based on semiconducting materials such as germanium.
Both technologies are able to detect gamma rays and subatomic particles emitted by nuclear material. When gamma rays or particles strike a scintillation detector, they create light flashes that are converted to electrical pulses to help identify the radiation at hand. In a solid-state detector, incoming gamma rays or particles register directly as electrical pulses.
“Each reaction to a gamma ray takes a very short time — a fraction of a microsecond,” Wagner said.
“By looking at the number and the intensity of the pulses, along with other factors, we can make informed judgments about the type of radioactive material we’re dealing with.”
The release notes, however, that both approaches have drawbacks. A scintillation detector requires a large crystal grown from sodium iodide or other materials. Such crystals are typically fragile, cumbersome, difficult to produce and
