Gamma rays are the most energetic form of electromagnetic radiation, with a very short wavelength of less than one-tenth of a nanometer. They are emitted from the decay of radioactive material and thus are an indicator of the presence of a nuclear device such as a bomb. Gamma ray detectors are fairly common devices and may be in use at border crossings or checkpoints. Unfortunately, it would be impossible to widely distribute gamma ray detectors throughout the world to identify the presence of nuclear material.
To better enable the detection of nuclear radiation, Navy researchers have developed a novel technology which leverages the behavior of nanoparticles. The Navy scientists are leveraging discoveries that gamma rays initiate the aggregation of silver (Ag) atoms into nanoparticles (NPs). The nanocapsules can be suspended in a transparent resin that can be applied to walls and floors of shipping containers and other structures and allowed to dry. These clusters have fluorescent qualities and, when illuminated at the proper wavelength, will fluoresce. Periodic testing for fluorescence will reveal if gamma radiation was once present. In this manner the NPs may be useful in efforts to detect or track fissile materials and their by-products.
- Ag NPs could be tailored (selected or designed) so that the fluorescence of the supported NPs have a unique spectra if their formation was catalyzed by gamma radiation vs. other means (such as UV radiation or stoichiometric reduction by a chemical reactant)
- This passive detection system is not observable to individuals unless they have the proper illumination equipment and training
- The nanoparticles are expected to be indefinitely stable when suspended in transparent or other paintable or painted resins
- US patent 9,643,211 available for license
- Potential for collaboration with Navy researchers