Lab Seeking Commercial Partners for Detection Technology

Sandia spectral shape discrimination team, L-R: Patrick Doty, Patrick Feng, and Mark Allendorf (Dino Vournas, Sandia National Lab)

Sandia National Laboratory in Livermore, California is developing a new process that the lab says can make radiation detection in cargo and baggage more effective and less costly. Sandia lab is seeking partners to commercialize the new technology.

The process, known as spectral shape discrimination, makes use of a new type of nanomaterials called metal-organic frameworks. Adding a doping agent to these porous nanomaterials leads to emissions of red and blue lights when the material interacts with high-energy particles emitted from radiological or nuclear sources, enabling more effective detection of neutrons. The detection of neutrons is now both costly and technically challenging because of the difficulty in distinguishing neutrons from ubiquitous background gamma rays.

Current radiation detection methods are limited in terms of speed and sensitivity, using time to discriminate between neutrons and gamma rays, which can limit their effectiveness in dynamic scenarios, such as border crossings, cargo screenings, and nuclear treaty verification. This new technology monitors the color of light emissions, which have the potential to make the screening process easier and more reliable.

Sandia materials scientist Mark Allendorf says the team working on the new process approached the problem from a materials-chemistry perspective. “[I]t is easier to monitor the color of light emissions,” says Allendorf, “rather than the rate at which that light is emitted. That’s the crux of this new approach.”

Team member and materials scientist Patrick Doty read about the use of doping agents to increase the efficiency of organic light-emitting diodes (OLEDs). These agents — usually compounds containing heavy metals such as iridium — increase OLED brightness by absorbing the excited-state energy in the device that was not converted to light, which represents as much as 75 percent of the possible light output.

Combining the nanoporous metal-organic frameworks with the doing agents in the OLEDs, creating not only a light-emitting material, but lights emitting different colors. Filling the pores in the metal-organic frameworks with the a specific amount of doping agent can result in both the absorbed light and fluorescence emitting from the excited metal-organic frameworks.

The researchers discovered that the wavelengths of the emitted light would be a function of the type of high-energy particle interacting with the material. Doty notes that as a result, spectral shape discrimination “allows one particle type to be distinguished from another on the basis of the color of the emitted light.”

The Sandia researchers say the new technology works with scintillators, plastic materials that fluoresce when struck by charged particles or high-energy photons. as a result, the process can be attractive to companies who produce plastic and other organic scintillators used in radiation detection devices. Though work remains before it can move into the marketplace, Sandia is currently seeking commercial partners to whom they can license the technology.

Read more:

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• University, Company Partner on Contraband Nuclear Detector
• Nanoscale Nuclear Testing Capability Developed

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