Experiment Proves Laser-Driven Neutrons' Ability to Detect Nuclear Material
13 June 2013
Researchers at the Los Alamos National Laboratory recently demonstrated the ability of laser-driven neutrons to detect nuclear materials hidden in shipping containers, proving that neutrons can be considered an essential tool in the fight against nuclear smuggling, Photonics.com reports.
At the laboratory's Trident facility, the scientists used a single short-pulse laser-generated neutron beam to detect the presence and quantity of nuclear material in a shielded environment. The experiment breaks ground for the creation of smaller neutron generators that could be placed at critical locations across the globe to combat nuclear material smuggling. The technology could also eliminate the need to use interrogation methods that require huge static facilities or less powerful neutron generators with long measurement times when searching for nuclear materials.
For the purposes of their experiment, the researchers applied a burst of laser energy into a very thin foil target of deuterated plastic, where hydrogen atoms were substituted with deuterium isotopes, to produce neutrons. The energy burst, which was 50 times bigger than the world's electrical power output, lasted just one-half of one-thousandth of a billionth of a second (0.5 ps). When the laser burst reached the foil target, it passed much of its energy into the deuterium nuclei, which then increased its speed to turn into a beam travelling at about one-tenth of the speed of light, hitting a second metal target placed 5 mm beyond the foil. When the deuterons hit the second target, they generated a huge number of fast-moving neutrons, numbering up to 40 billion, in a bunch lasting a billionth of a second. This novel approach provided positive proof of nuclear material available, the Italian researcher who led the experiment, Andrea Favalli, explained.
The researchers interrogated two containers, an empty one and a closed one containing nuclear material, discovering that this laser-driven neutron approach could not only detect the presence of nuclear material, but measure the exact quality of the material as well.
This neutron interrogation method could be also used in biological science applications, and lasers could facilitate its use in other laboratories and universities.