New carbon foam can detect neutrons emitted by radioactive material

Giving a boost to vital security initiatives, a team of researchers have successfully shown that boron-coated vitreous carbon foam can be used in the detection of neutrons emitted by radioactive material.

Detecting neutrons is key to counterterrorism initiatives, such as screening cargo containers and other applications in nuclear power instrumentation, workplace safety and industry.

As the usual detection material, helium-3, has become harder to obtain, the demand for detectors has risen dramatically over the past decade.

Boron is abundant and relatively less expensive compared to helium-3. "The use of a coated foam disperses the boron evenly throughout the detector volume, increasing efficiency by filling in otherwise empty space," said Christopher Lavelle of Johns Hopkins University.

A process called noble gas scintillation can be controlled and characterized precisely enough to detect the neutrons emitted by radioactive materials.

Scintillation is a process where energetic particles produce flashes of light while passing through certain materials. Sensitive light detectors record the rate at which these light flashes occur to measure the presence and intensity of neutrons in the environment.

Neutrons captured deep within the coated foam produce large enough flashes to be detected by light detectors outside the foam, found the experiment.

The study appeared in the journal Applied Physics Letters.