Journal of the Institute of Electronics and Information Engineers (전자공학회논문지)

The Institute of Electronics and Information Engineers (대한전자공학회)
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Design and Fabrication of HgI2 Sensor for Phosphor Screen based flat panel X-ray Detector

형광체 스크린 기반 평판형 X선 검출기 적용을 위한 요오드화수은 필름 광도전체 센서 설계 및 제작

  • Park, Ji Koon (Dept. of Radiological Science, International University of Korea) ;
  • Jung, Bong Jae (Dept. of Radiological Science, International University of Korea) ;
  • Choi, Il Hong (Dept. of Radiological Science, International University of Korea) ;
  • Noh, Si Cheol (Dept. of Radiological Science, International University of Korea)
  • 박지군 (한국국제대학교 방사선학과) ;
  • 정봉재 (한국국제대학교 방사선학과) ;
  • 최일홍 (한국국제대학교 방사선학과) ;
  • 노시철 (한국국제대학교 방사선학과)
  • Received : 2014.11.11
  • Accepted : 2014.12.04
  • Published : 2014.12.25
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Abstract

In this study, from a new x-ray detector that combines a columnar CsI:Na scintillation layer with a photosensitive mercuric iodide layer was investigated. In this structure, X-rays are converted into visible light on a thick CsI:Na layer, which is then converted to electric charges in a thin $HgI_2$ bottom layer. The thin coplanar mercuric iodide films as a photosensitive converter requiring only a few tens of volts of bias, associated with a thick columnar coating of phosphor layer, were simulated and designed. The results of this research suggest that the new coplanar x-ray detector with a hybrid-type structure can resolve the following problems: high voltage from the a-Se, and low conversion efficiency from the indirect conversion method. The results of this research suggest that the new CsI:Na/$HgI_2$ x-ray detector with a double-layer type structure can resolve the following problems: high voltage from the direct conversion method, and low conversion efficiency from the indirect conversion method.

본 연구에서는 새로운 구조의 X선 영상 검출기로써 광민감 $HgI_2$ 층이 포함된 CsI:Na 형광층의 구조를 설계하였다. 이러한 구조에서 X선은 두꺼운 CsI:Na 층에서 가시광선으로 변환된 후 하부의 얇은 $HgI_2$ 층에서 전하로 변환된다. CsI:Na와 $HgI_2$로 구성된 복합구조의 두께를 최적화하기 각 층의 두께를 변화시켜 X선에 대한 흡수효율을 시뮬레이션 하였다. 현재 상용화된 a-Se 단일층의 검출기는 수십 kV의 고전압이 요구되고, CsI:Na/a-Si 구조의 간접변환 방식은 낮은 변환효율을 가지는 단점이 있다. 본 연구의 결과로 제시된 새로운 형태의 CsI:Na/$HgI_2$ 복층 구조의 x-ray 검출기는 고전압이 필요한 직접 변환방식의 단점과 간접 변환방식의 낮은 효율을 보완할 수 있을 것으로 생각된다.

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References

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