Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New materials discovered to detect neutrons emitted by radioactive materials

05.03.2015

Scientist Christopher Lavelle of the Johns Hopkins University Applied Physics Laboratory, together with a team of researchers from the University of Maryland and the National Institute of Standards and Technology, has successfully shown that boron-coated vitreous carbon foam can be used in the detection of neutrons emitted by radioactive materials -- of critical importance to homeland security. Lavelle is lead author of the paper "Demonstration of Neutron Detection Utilizing Open Cell Foam and Noble Gas Scintillation" released today in the journal Applied Physics Letters.

Detecting neutrons is key to counterterrorism activities, such as screening cargo containers, as well as other vital applications in nuclear power instrumentation, workplace safety and industry. The demand for detectors has risen dramatically over the past decade while at the same time the usual detection material, helium-3, has become harder to obtain. An advantage of the approach outlined in the paper is that boron is abundant and relatively low cost compared to helium-3. The use of a coated foam, in particular, disperses the boron evenly throughout the detector volume, increasing efficiency by filling in otherwise empty space.


This is a close-up image of the boron carbide coated reticulated carbon foam sample used in the experiments.

Credit: JHU/APL

Lavelle and his colleagues' work builds on a series of experiments conducted with scientists at NIST and the University of Maryland that had demonstrated that a process called noble gas scintillation can be controlled and characterized precisely enough to detect the neutrons emitted by radioactive materials. Scintillation refers to a process where energetic particles produce flashes of light when passing through certain materials, in this case xenon gas. Sensitive light detectors record the rate at which these light flashes occur to measure the presence and intensity of neutrons in the environment.

In a follow-on experiment, the research team obtained samples of "carbon foam" coated with boron carbide and placed them in xenon gas. The boron-10 isotope in the coating readily absorbs neutrons. Following neutron absorption, energetic particles are released into the gas and create flashes of light. In this experiment, researchers determined that neutrons captured deep within the coated foam produce large enough flashes to be detected by light detectors outside the foam. Previously, there had been some doubt as to whether the light flashes would actually escape foam, or if the foam would completely shadow them from the light detector.

The next steps in the series of experiments include investigating other unique detector geometries, such as multiple layers of boron-coated thin films, the use of optically transparent neutron absorbers, and finalizing a design for a potential prototype detector.

###

Media contact: Gina Ellrich, 443-778-7796, Gina.Ellrich@jhuapl.edu

The Applied Physics Laboratory, a not-for-profit division of The Johns Hopkins University, meets critical national challenges through the innovative application of science and technology. For more information, visit http://www.jhuapl.edu.

Media Contact

Gina Ellrich
gina.ellrich@jhuapl.edu
443-778-7796

 @JohnsHopkins

http://www.jhu.edu 

Gina Ellrich | EurekAlert!

More articles from Materials Sciences:

nachricht ADIR Project: Lasers Recover Valuable Materials
21.07.2017 | Fraunhofer-Institut für Lasertechnik ILT

nachricht High-tech sensing illuminates concrete stress testing
20.07.2017 | University of Leeds

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>