| Project/Area Number |
08555156
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Inorganic materials/Physical properties
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| Research Institution | SHONAN INSTITUTE OF TECHNOLOGY |
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Principal Investigator |
ISHII Mitsuru SHONAN INSTITUTE OF TECHNOLOGY,FACILITY OF ENGINEERING,PROFESSOR, 工学部, 教授 (80212827)
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| Co-Investigator(Kenkyū-buntansha) |
USUKI Yoshiyuki FURUKAWA CO., SENIOR RESEARCHER, いわき工場, 主任研究員
ISHIBASHI Hiroyuki HITACHI CHEMICAL CO., LTD.RESEARCHER, 筑波開発研究所, 研究員
HARA Kazuhiko TSUKUBA UNIVERSITY,INSTITUTE OF PHYSICS,LECTURE, 物理学系, 講師 (20218613)
KOBAYASHI Masaaki HIGH ENERGY ACCELERATOR RESEARCH ORGANIZATION, 素粒子原子核研究所, 教授 (40013388)
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| Project Period (FY) |
1996 – 1997
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| Keywords | Lead Tungustate / Gadolinium Silicate / Czochralski Growth / Single crystal / Radiation Damage / Scintillation Characteristics / Optical Transmittance / Charge compensation |
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| Research Abstract |
1.PWO (PbWO_4)
1) To begin with, we tried to purification by multi-crystallization for the purpose of improvement on scintillation characteristics. Taking in to consideration the deficiency of the three time crystallized samples, we added a maximum of 200ppm of La^<3+> which is larger valence than Pb^<2+> grew crystals and made evaluation thereon. Consequently, PWO it was found that PWO : La is larger light output and faster decay and indicating that it shows more superior radiation hardness. As for the dopants for charge compensation, the same effects were found in Y,Ga, La and Nb beside La.
2) Based on these results, we grew the crystals with phi 65x280mmL and produced such practical segments of 20x20x230mm^3 for trial purpose and established the production process technology of scintillators. The crystal produced for trial purpose was found superior radiation hardness and confirmed for first time in the world to be into practical use as a scintillation detector of high energy particles.
2.GSO (Gd_2SiO_5)
1) In the development of GSO,we established the growth technology of such larger size crystal as phi 80x300mmL by modified growth condition. We produced scintillation segments with 5x25x260mm^3 from grown crystals by application of this technology for trail purpose and examined the cutting-polishing process.
2) In GSO : Ce, we found that there ARE two phenomena of increase and decrease in light output due to gamma-ray irradiation. The smallest composition for these phenomena is existed to locate near as 1.0% Ce.
3) We produced two kinds of large sized crystals of 0.5,1.5mol% in Ce and investigated stability of light output under gamma-ray irradiation and scintillation characteristics for practical sized crystals.
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