• 제목/요약/키워드: Scintillation

검색결과 442건 처리시간 0.036초

Feasibility Study of Diffusion Film for the Light Guide of Gamma Ray Imaging System

  • Cha, Hyemi;Min, Eungi;Lee, Kisung;Jung, Young-Jun;Lee, Hakjae
    • IEIE Transactions on Smart Processing and Computing
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    • 제6권2호
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    • pp.124-128
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    • 2017
  • A light guide improves the spatial resolution of a gamma ray imaging system by diffusing the scintillation light. Similarly, light diffusion film, which has been applied to flat-panel-display engineering, spreads the light from the light guide panel. In this study, we adopted light diffusion film for the light guide of a gamma ray imaging system, and evaluated its diffusion characteristics. We compared the light diffusion performance of the film to an ordinary acrylic plate. As a result, the diffusion film widely spreads scintillation light. As for the thickness of the light guide, we acquired more distinct images with three films overlapped than with an acrylic plate. We expect light diffusion film to be a promising candidate for light guides in gamma ray imaging systems.

리튬 루테튬 보레이트 섬광단결정의 잔광 특성 (Afterglow Properties of LLBO Scintillation Crystal)

  • 김성환
    • 센서학회지
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    • 제23권6호
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    • pp.416-419
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    • 2014
  • We grew a $Li_6Lu(BO_3)_3:Ce^{3+}$ single crystal as a new scintillator. And, the scintillation and thermoluminescence properties of the scintillator were determined. The emission spectrum of $Li_6Lu(BO_3)_3:Ce^{3+}$ is located in the range of 370~530 nm, peaking at 416 nm and 439 nm, due to the $5d{\rightarrow}4f$ transition of $Ce^{3+}$ ions. The fluorescence decay time of the crystal is composed two components. The fast component is 34 ns (84%) and the slow component is 125 ns (16%) of the crystal. The afterglow is caused by the electron and hole traps in the crystal lattice. We determined physical parameters of the traps in the crystal. The thermoluminescence trap are composed a trap. The determined activation energy (E) and frequency factor (s) of the TL trap are 1.05 eV and $4.4{\times}10^{10}s^{-1}$, respectively.

CsI:Gd 결정 육성과 섬광 특성 (Crystal Growth and Scintillation Properties of CsI:Gd)

  • 천종규;김성환;김홍주
    • 센서학회지
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    • 제21권4호
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    • pp.293-297
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    • 2012
  • CsI:Gd crystal was grown by the Bridgeman method and its scintillation properties were investigated. The wavelength peak of the luminescence spectrum for the crystal excited by X-ray was 419 nm. The range of the spectrum was from 300 nm to 800 nm. The spectrum well matched to the quantum efficiency of a typical bi-alkali photo-multiplier tube(PMT). An energy resolution of 48.2 % was obtained for 662 keV ${\gamma}$-rays of $^{137}Cs$. The three decay times were obtained as a fast(557.4 ns, 42.2 %), intermediate (1.78 ${\mu}s$, 29.7 %) and slow (5.43 ${\mu}s$, 28.1 %) components, respectively.

혈청 HCG 섬광근접측정법(Scintillation Proximity Assay)의 기초연구

  • 최태현;최창운;임상무;우광선;정위섭;임수정;이수진
    • 한국원자력학회:학술대회논문집
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    • 한국원자력학회 1998년도 춘계학술발표회논문집(2)
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    • pp.725-729
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    • 1998
  • 방사성 동위원소를 이용한 체외진단 측정법으로 RIA가 가장 널리 쓰여져 왔으나, 결합분획과 유리분획의 분리과정에서 오는 번거로운 단점을 개선하기 힘들었다. 1979년 Hart와 Greenwald에 의해 소개된 섬광근접측정법(Scintillation Proximity Assay, SPA)을 이용하여 RIA의 단점을 극복하고자 하는 연구가 시작되었다 주로 사용되는 방사성동위원소로 $^3$H, $^{125}$/I이 추천되는 핵종이며, 이 중에서 $^{125}$/I을 이용한 hCG(human chorionic gonadotropin) 체외진단법으로서 SPA의 기초연구를 수행하였다. SPA bead와 방사능 크기에 따라 측정되는 자연계수치의 증가와 hCG 표준물질을 농도별로 희석하여 유의성을 가지고 있는지 확인하였고, hCG 농도가 높은 것으로 판명된 환자의 혈청을 측정하여 임상적용의 가능성을 확인하였다.

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절대유량법(ASFM)을 이용한 저낙차.카플란 수차효율측정 적용사례 연구 (Case study of a low head & kaplan turbine efficiency measurement using ASFM)

  • 이용준;오석영;신창식;현정재
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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    • pp.205.1-205.1
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    • 2011
  • This study concerns a low head and kaplan turbine efficiency measurement using the acoustic scintillation flow meter(ASFM). The ASFM is one of absolute discharge measurement methods because it measures velocity-area of discharge with couples of transducers. This study shows that the highest efficiency of turbine is 87.7% and the efficiency is 85.8% in the rated output(600kW). The test result is reliable because the efficiency trend from this test is similar to the result of index test conducted in 1986. In this paper, the principle, measurement methods, application and test procedures of the test are discussed.

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Tritium( $^3$H) Activity Measurement by the Liquid Scintillation Counting Method

  • Hwang, Sun-Tae;Oh, Pil-Jae;Lee, Min-Kie;Kim, Wi-Soo
    • Journal of Korean Society for Atmospheric Environment
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    • 제10권E호
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    • pp.299-302
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    • 1994
  • At a nuclear power plant, environmental radioactivity monitoring is routine work for the radiation safety management For the environmental monitoring of tritium($^3$H) activity in water sampled liquid scintillation counting( LSC) method is applied to measure low- energy beta activity from tritium in the samples. The $^3$H activity is measured using the BECKMAN 5801 system at the KRISS( Korea Research Institute of Standards and Science) for evaluating the lower limits of detection( LLD) of $^3$H measurement and the measuring capability of low-level $^3$H activity at four nuclear Power Plant sites. The LSC systems used for low-level $^3$H activity measurements at the nuclear Power Plants are confirmed to satisfy throughout an intercomparison study under the experimental arrangements by the KRISS.

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