"Uranium and plutonium, like every chemical element, has a spectral signature that's as unique as every human's DNA or fingerprint," Russo says. "With LAMIS, we can factor in isotopic ratios, giving us an additional level of identification that could be critical."
For example, "yellow cake," the powdered concentrate made from uranium ore that is a main ingredient of nuclear fuel, can also be used to fabricate a nuclear weapon. Measuring the elemental composition of yellow cake is one way of identifying the geographic locale where the yellow cake was produced, but because uranium ore is ubiquitous to our planet's surface, being able to also measure isotopic ratios in a sample of yellow cake can be a huge advantage for pinpointing where it originally came from.
"The natural ratio of uranium-235 to uranium-238 is defined by the geology of our planet," Russo says. "If you find a modified ratio in a sample then you know someone has been enriching that uranium. Other isotopic ratios within a nuclear reaction chain also can tell you how a nuclear weapon was made and where it might have originated."
Much of this research was done in collaboration with Applied Spectra, a company Russo created in 2004 with the help of Small Business Innovation Research grants, to bring laser ablation spectroscopy technology to the marketplace.
"The next step is to improve the sensitivity and precision of LAMIS," Russo says. "Our immediate target is parts-per-million, which should be relatively easy for us to reach, but ultimately we want to get to parts-per-billion sensitivity, which will be a challenge. However, 50 years ago, the parts-per-billion sensitivity of today's mass spectrometry technologies would have been thought impossible."'/>"/>
|Contact: Lynn Yarris|
DOE/Lawrence Berkeley National Laboratory