London, August 19 : Scientists from the Lawrence Livermore National Laboratory in California have produced a new detector sensitive even to low levels of gamma radiation.
US shipping ports receive about 6 million cargo containers each year. Officials would like to be able to check each one for smuggled nuclear material, but today's detectors cannot process such numbers in a reasonable time.
These devices typically require an officer to search inside each container.
The gamma rays produced by radioactive materials can pass through containers relatively easily, but uranium produces only small amounts of such radiation.
Now, according to a report in New Scientist, Joseph Farmer and colleagues at the Lawrence Livermore National Laboratory in California have produced a new detector sensitive even to low levels of gamma radiation.
Their device is set to speed up screening times.
It doesn't directly detect gamma rays themselves, but instead looks for the hydrogen peroxide generated when the rays interact with water.
The detector consists of an "electronic nose" chip coated with a thin layer of water that is condensed onto its surface. When gamma rays strike water molecules in that layer, the nose chip detects any hydrogen peroxide formed.
According to the inventors, as well as being more sensitive, their design can pick up a wider range of gamma ray energies than conventional detectors.