计算物理 ›› 2002, Vol. 19 ›› Issue (3): 195-202.

• 论文 • 上一篇    下一篇

CsI:Na(CsI:Tl)荧光透过率和对X射线的转换因子

徐向晏, 牛憨笨   

  1. 中国科学院西安光学精密机械研究所, 光电子部, 陕西 西安 710068
  • 收稿日期:2000-09-25 修回日期:2001-01-08 出版日期:2002-05-25 发布日期:2002-05-25
  • 作者简介:徐向晏(1973-),男,甘肃,博士生,从事X射线成像方面的研究.

THE FLUORESCENCE ESCAPE EFFICIENCY OF CsI:Na(CsI:Tl) PHOSPHOR AND ITS CONVERTING FACTOR TO X-RAYS

XU Xiang-yan, NIU Han-ben   

  1. Xi'an Institute of Optics and Precision Mechanics, Academia Sinica, Xi'an 710068, P R China
  • Received:2000-09-25 Revised:2001-01-08 Online:2002-05-25 Published:2002-05-25

摘要: 在建立模型的基础上,较为全面地分析了CsI:Na(CsI:Tl)X射线转换屏的荧光透过率及对X射线的转换因子,明确了转换因子与X光子能量、转换屏厚度、衬底反射率、荧光吸收系数之间的函数关系.计算表明,荧光透过率(及转换因子)与衬底反射率和1/(σL)值有较强的关系,为有较高的荧光透过率,实际制作的CsI:Na转换屏的1/(σL)值应在10以上,最好能达到30~40.在相同情况下,反射方式的转换因子高于透射方式.用增加厚度来提高转换因子时应考虑荧光透过率降低的负面影响.可选择适当的CsI:Na(CsI:Tl)厚度使转换因子最佳.

关键词: csI:Na(CsI:Tl), X射线成像, 转换因子, 荧光透过率

Abstract: A model for the fluorescence escape efficiency of CsI:Na(CsI:Tl) phosphor is proposed,and the converting factor of CsI:Na(CsI:Tl) to X-rays is discussed in detail.Calculated results show that the fluorescence escape efficiency,as well as the converting factor,strongly depends on the substrate reflectivity and 1/(σL)(σ is the absorption coefficient of CsI:Na(CsI:Tl) to fluorescence, and L is the phosphor layer thickness.).For a phosphor,1/(σL) should be above 10,and 30~40 is even better.In point of converting factor and spatial resolution,the reflection model is superior to the transmission model.The maximum converting factor can be obtained by optimizing the phosphor layer thickness.

Key words: CsI:Na (CsI:Tl) phosphor, X-ray imaging, converting factor, fluorescence escape efficiency

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