Low background high efficiency radiocesium detection system based on positron emission tomography technology.

Area of Science:

• Nuclear Physics
• Environmental Science
• Medical Imaging Technology

Background:

• The 2011 Fukushima nuclear accident highlighted the need for sensitive radiocesium detection in food.
• Existing detectors, like germanium detectors, are costly and bulky.
• There is a demand for more accessible and efficient radiocesium monitoring solutions.

Purpose of the Study:

• To develop a novel, cost-effective radiocesium detector.
• To leverage positron emission tomography (PET) principles for enhanced detection.
• To improve the sensitivity and reduce the detection limit for radiocesium in food samples.

Main Methods:

• Employed positron emission tomography (PET) technology with coincidence detection.
• Utilized eight Bi4Ge3O12 (BGO) scintillation detectors in a double-ring configuration.
• Implemented a PET data acquisition system for coincidence measurements of gamma photons.

Main Results:

• Achieved selective measurement of radiocesium (134Cs) by detecting coincident gamma photons.
• Reduced detection limits by effectively filtering out single gamma photons from other isotopes like (40)K.
• Demonstrated an average detection efficiency of 12% for (134)Cs.
• Achieved a minimum detectable concentration below 25 Bq/kg, surpassing Japanese food monitoring requirements.

Conclusions:

• The developed radiocesium detector, based on PET technology, is a promising tool for low-level radiocesium detection.
• This technology offers a more affordable and efficient alternative to traditional detectors.
• The system shows potential for widespread application in food safety and environmental monitoring.