Summary:
UCLA researchers from the Department of Materials Science and Engineering have developed a novel nanocomposite material for high-efficiency radiation detection and monitoring.
Background:
Scintillators are materials that emit light when they absorb radiation, such as gamma rays or x-rays. The photons generated by the scintillators can be measured on external detectors like photomultiplier tubes or other photodetectors, enabling diverse applications in industrial radiation screening and medical imaging. Large gamma scintillators are used in industrial screening at ports of entry to monitor radiation in luggage and shipping containers, requiring scintillating materials with low natural radioactive backgrounds. By contrast, medical image applications rely on very fast scintillators that can precisely localize the line path of positrons in positron emission tomography (PET). While some commercial scintillators exist for these applications individually, no material has both a low natural radioactive background and very fast emission times. There is a need for new scintillation materials to overcome these challenges simultaneously.
Innovation:
Professor Qibing Pei and colleagues in UCLA’s Department of Materials Science and Engineering have developed a new composite scintillation material that incorporates high atomic number nanoparticles into a plastic matrix. The percentage of nanoparticles in the matrix can be tuned based on the desired application. This nanocomposite material is produced using standard manufacturing methods and can be manufactured in thicknesses up to the centimeter length scale. The researchers show their material outputs 50% more light compared to commercially available scintillators and has the highest radiation peak detection limit reported in the literature, enabling very high throughput and low background radiation. They further report ultrafast material emission times on the nanosecond scale. Combined with its high environmental stability, this material could be used to replace conventional plastic scintillators in numerous applications.
Potential Applications:
• Medical imaging (CT, PET)
• Nuclear reactor leak detection & monitoring
• Neutrino detection
• Airport luggage screening
• Shipping cargo screening
Advantages:
• Low background radiation
• High emission response time
• High environment stability
• Tunable nanoparticle composition
• High optical transparency
Development-To-Date:
Researchers have designed, built, and characterized the radiation detection capabilities of the material, demonstrating low background signal and gamma-ray detection.
Related Papers:
Yu, H., Winardi, I., Han, Z., Prout, D., Chatziioannou, A., and Pei, Q. Fast Spectroscopic Gamma Scintillation Using Hafnium Oxide Nanoparticles-Plastic Nanocomposites. ACS Chemistry of Materials, 2024, 36, 1, 533-540.
Reference:
UCLA Case No. 2024-126