Hokkaido University Research Profiles


Development of Gd?Si?O?-based High-performance Scintillators and Their Application

Development of high luminescence scintillators for radiation detectors

Scintillators are materials that emit light by radiation and are used in medical diagnostic equipment, and for oil exploration and other purposes. Gd2Si2O7 (GPS) scintillators have excellent features such as high luminescence, high energy resolution and non-tidal dissolution, and can be made into single crystals, ceramic plates and powders.

Content of research

The Gd2Si2O7: Ce (GPS) single crystal scintillator has excellent features such as high luminescence (1.4 times that of NaI:Tl), high energy resolution, non-tidal and no self-radioactivity, and can be used in high temperature environments of 250°C or higher. The technology has been transferred to Oxide Corporation, and is now ready for use in SPECT and other applications. We have also established a stable manufacturing technology for 5 cm square GPS sintered plates. By combining a position sensitive photomultiplier tube, it is now possible to detect nuclear fuel materials emitting alpha rays, which were released in the Fukushima Daiichi Nuclear Power Plant accident, with high sensitivity. The prototype device succeeded in detecting nuclear fuel-induced α-ray-emitting radionuclides in an environment with nuclear fuel-induced α-ray-emitting radionuclides: natural radioactivity (radon progeny) = 1:200, which had been inconceivable with conventional devices.

  • Temperature dependence of luminescence in the high temperature GPS environment. Greatly surpassing GSO (the conventional product)

  • Prototype of a portable alpha-ray detection system using GPS plates

  • Example of discrimination of α-ray-emitting radon progeny from nuclear fuel in a 50:1 environment

Potential for social implementation

  • ・Can be used in high temperature environments of 250°C or higher as a γ-ray probe for underground resource exploration
  • ・SPECT/PET equipment for the heart and small animals
  • ・On-site detection of plutonium

Appealing points to industry and local governments

We are engaged in vertically integrated manufacturing related to radiation measurement, ranging from the development of new radiation measurement materials such as diamonds, compound semiconductors and oxide scintillators to the development of measurement systems. We are also cooperating in decommissioning and reconstruction projects in Fukushima.

Intellectual property related to this research

特願2014-029357 「単結晶、放射線検出器及び放射線検出器の使用方法」
特許 第5971866号「シンチレータプレート、放射線計測装置、放射線イメージング装置およびシンチレータプレート製造方法」