US-based scientists have developed a new gamma radiation detection method that could launch the next generation of nuclear weapons identification systems.
Working at Illinois' Northwestern University, the research team has created new elemental materials capable of confirming the presence of so-called ‘hard radiation' - high energy gamma rays or X-rays that can penetrate comparatively thick substances. It's precisely that ability that normally makes this type of radiation difficult to pick up on but hopes are high that the university's advances could have future security applications in the modern world.
"We have designed promising semiconductor materials that, once optimised, could be a fast, effective and inexpensive method for detecting dangerous materials such as plutonium and uranium", head researcher Mercouri G Kanatzidis explained, in a statement.
He and his colleagues initially drew on heavy elements with a comparatively high radiation absorption level to put their hard radiation detection technique to test. When heavy radiation entered these elements, it activated the electrons inside. This activity generated a signal which both confirmed the radiation's presence and allowed its identity to be confirmed.
However, the team encountered one issue during their experiments - how to distinguish between the electrons in the radiation and those naturally found in the elements. As detailed by Kanatzidis, to overcome this, they ended up actually manufacturing their own material.
"It's like having a bucket of water and adding one drop - the change is negligible", he said. "We needed a heavy element material without a lot of electrons. This doesn't exist naturally so we had to design a new material."
Consequently, the researchers developed two substances - cesium-mercury-selenide and cesium-mercury-sulfide - and subsequently showed that both of them could effectively detect gamma rays. According to Kanatzidis, once further radiation detection materials research has taken place - optimising the materials so they're working at their best - they have the potential to offer greater performance than present-day hard radiation detection produces.
The materials have clear security industry applications but other industries, such as biomedicine, might also be able to put them to use.
Northwestern University's hard radiation detection research was supported by two US government organisations - the Defense Threat Reduction Agency and the Department of Homeland Security. In-depth details of their work appear in a paper called Dimensional Reduction: A Design Tool for New Radiation Detection Materials.
Image copyright Irvin Calicut at ml.wikipedia
See also:
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