- Address
- 305-0044 茨城県つくば市並木1-1 [アクセス]
研究内容
出版物2004年以降のNIMS所属における研究成果や出版物を表示しています。
所属学会
日本結晶成長学会, 応用物理学会, American Ceramic Society
電子・光機能材料研究センター
Oxide and halide single-crystals for radiation detection
Single-crystal growth, Crystal defects engineering, Scintillators, Radiation detection
概要
Inorganic single-crystal radiation detectors are widely employed in the fields of homeland security, industrial nondestructive inspection, nuclear medicine imaging, and high-energy physics. Even though depending on the specific application the required properties vary, there is a general market demand for scintillators that are chemically stable, cost-effective, and efficient.
Two distinct application-oriented topics are mainly focused: (1) thermal neutron scintillators for handheld detectors (stable oxides instead of the currently used highly hygroscopic halides) and (2) new X/γ-rays scintillators (good air-stability, high light yield, excellent non-proportionality).
新規性・独創性
• Development of non-hygroscopic thermal neutron scintillator Ce:Li6Y(BO3)3 (LYBO): (1) greatly reduced scattering centers for the first time, (2) high light yield over 4000 ph/n, (3) inch-size bulk crystal growth.
• Finding of a new chemically-stable and bright halide scintillator Cs3Cu2I5 (CCI) that can be grown into large-size single crystals via the melt method.
内容
• The previously disregarded Ce: LYBO due to extremely low light yield has been developed using the strategies of proper Ce3+-doping and drastic reduction of scattering centers, with the light yield being comparable to the reference Li-glass (GS20).
• Large-size crystal growth of the new iodide scintillator CCI is achieved by the melt method that is practicable in mass production. Tl:CCI exhibits a high light yield, good energy resolution, and excellent non-proportionally (less than 3%) while being chemically-stable compared with the commercial halide scintillators such as NaI and SrI2.
まとめ
• High light yield of Ce:LYBO makes this family practically promising for handheld neutron detection. The successful strategies will be extrapolated to other low melting-point oxide scintillators.
• The stable and bright scintillator CCI has gained great attention worldwide. After doping, the optimized Tl:CCI has been found even brighter that the commercial Eu:SrI2.