Sensors & Electronics
Awards & Recognition
R&D 100 Awards
PUMA is a unique radiation sensor comprised of lightweight, flexible glass fibers that provides portable, real-time measurements of neutrons and gamma rays.1999 - PUMA Fiber Optic Neutron and Gamma Ray Sensor
Developers: Mary Bliss, Ned A. Wogman, Ronald L. Brodzinski, Richard W. Perkins, Bruce D. Geelhood, Walter K. Hensley, Richard S. Seymour, William Richardson (Oxford Instruments)
PUMA is a revolutionary radiation monitoring system that uses glass fibers to detect the presence of radionuclides such as plutonium. This flexible, lightweight, low-power detection system can be used to monitor an inventory of nuclear materials and has significant potential in countering the threat of nuclear terrorism and contributing to international nonproliferation efforts.
The innovative use of glass fibers is a breakthrough in the field of radiation detectors. Glass fibers offer substantial flexibility over conventional neutron sensor technologies, most of which use rigid helium-filled tubes. PUMA's glass fibers contain lithium-6 atoms and cerium ions that detect the presence of radionuclides such as plutonium. The neutrons react with the lithium isotope to leave an ionization trail through the glass matrix, which results in light emission from the cerium. The fiber is coated with a low refractive index silicone polymer, which maximizes the amount of light captured in the glass fiber. The trapped light travels down the fiber and is detected at the ends using photomultiplier tubes. Each fiber can detect from one to millions of neutrons and gamma rays per second. The researchers have developed glass compositions specifically for fiber drawing and manufacturing processes that enable fiber to be produced in useful lengths of more than 200 cm (2 meters).
Excerpted from PNNL R&D 100 webpage.
Selected Links to Related Information:
- Related Examples (Same Project)
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- Fiber-Optic Neutron and Gamma Ray Sensor - 1999 FLC Award Winner