• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to previous page

Determination of the excited states of the electron centers and recording-readout processes in the X-ray storage material BaFBr

Research Project

Project/Area Number 09450002
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field Applied materials science/Crystal engineering
Research InstitutionTohoku University

Principal Investigator

KONDO Yasuhiro  Graduate School of Engineering, Tohoku University Associate Professor, 大学院・工学研究科, 助教授 (20013534)

Project Period (FY) 1997 – 1998
Project Status Completed (Fiscal Year 1998)
Budget Amount *help
¥5,700,000 (Direct Cost: ¥5,700,000)
Fiscal Year 1998: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1997: ¥4,700,000 (Direct Cost: ¥4,700,000)
KeywordsX-ray Imaging / Imaging Plate / Photo-Stimulated Luminescence / Phosphors / Luminescence / Electron trap centers / 2-D detectors / Detectior of InfraRed Light / 二次元検出器 / 画像記録 / X線 / イオン結晶 / 色中心 / 発光分光 / 励起状態 / 赤外分光 / 光物性
Research Abstract

In the storage phosphor of the X-ray image material, the X-ray photons generate electrons and holes which are trapped at vacancies and Eu^<++> impurities in the micro crystals ofBaFBr : Eu^<++>(storage process) and photoexcitation of the trapped electron induces the recombination of the electrons and holes at Eu impurity, emitting the uv-luminescence. This uv-luminescence is recorded and is used to construct the X-ray image (readout process). Although the storage-readout mechanism described above has been proposed in the early stage of the invention of the imaging plate, the storage-readout process is still controversial at present. To establish the clear model for the mechanism, I tried to measured thermal stability of the excited state of the trapped electrons and also to clarify the recombination path of the electrons and holes. For this measurements, a system for the infrared luminescence was constructed. Results are summerized as follows.
1) The temperature dependence of the luminescence intensity and its lifetime of the F center were measured and the thermal activation energy of the F centers in the excited state was obtained. This mechanism is identical to the that proposed by Takahashi.
2) The F(F^-)-center luminescence in the IP was measured for the first time and it is also shown that F(Br^-) center does not emit any IR luminescence. These results shows that the electron center can migrate in the micro crystals in the IP and that the fading of the stored image might be induced by the migration of holes which are thermally activated in shallowly trapped hole centers.

Report

(3 results)
  • 1998 Annual Research Report   Final Research Report Summary
  • 1997 Annual Research Report
  • Research Products

    (2 results)

All Other

All Publications (2 results)

  • [Publications] Yasuhiro Kondo, Kiyoshi Inoue, and Nobufumi Mori: "Luminuescence Study of F(Br-) and F(F-) Centres in BaFBr" Radiation Effects and Defects in Solids. 147(印刷中). (1999)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] Yasuhiro Kondo, Kiyoshi Inoue, and Nobufumi Mori: "Luminescence Study of F (Br-) and F (F-) Centres in BaFBr" Radiation Effects and Defects in Solids. Vol.147 (in press). (1999)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary

URL: 

Published: 1997-04-01   Modified: 2016-04-21  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi