X射线在影像增强器中散射特性的研究

计算物理 ›› 2000, Vol. 17 ›› Issue (3): 298-306.

X射线在影像增强器中散射特性的研究

郭金川, 牛憨笨

中国科学院西安光学精密机械研究所, 陕西西安 710068

收稿日期:1998-09-26 修回日期:1999-06-28 出版日期:2000-05-25 发布日期:2000-05-25
作者简介:郭金川(1964~),male,Lecturer,PhD.
基金资助:
Supported by the National Natural Foundation of China

STUDY OF SCATTERING PROPERTIES OF X RAYS IN INTENSIFIERS

GUO Jin-chuan, NIU Han-ben

Xi'an Institute of Optics and Precision Mechanics, Academia Sinica, Xi'an 710068, P R China

Received:1998-09-26 Revised:1999-06-28 Online:2000-05-25 Published:2000-05-25
Supported by:
Supported by the National Natural Foundation of China

摘要/Abstract

摘要： X射线在影像增强器中的散射是影响X射线影像增强器输出图像对比度和分辨率的主要因素。首先用MonteCsrolo方法模拟了轫致辐射X射线与影像增强器的输入转换屏(CsI:Na)的作用过程,给出了透过转换屏的X射线的能谱。然后以无限大平面铁板作为增强器内电极和管壳的几何模型,以CsI:Na的透过X射线能谱为铁板模型的入射能谱,分析了X射线在影像增强器中的背向散射特性。X射线管电压为20~120kV,转换屏厚度范围为200~400μm。结果表明,随着X射线管电压的升高,背向散射光子数增加,其平均能量也迅速增加;转换屏越厚,背向散射光子数越少。

关键词: 影像增强器, 轫致辐射, 背向散射, Monte Carolo方法

Abstract: The interaction processes of bremsstrahlung X rays with CsI:Na scintillator of different thickness(200~400 μm) are first simulated by means of Monte Carlo analysis. The energy spectra of exit photons from CsI:Na are presented, which are used as the incident spectra on iron, the constituents of the inner electrodes and shell of intensifiers. The backscattering properties of X rays in intensifiers are analyzed. The potential producing bremsstrahlung X rays is 20~120 kV. Results show that with the increase of X ray tube potential the number of backscattered photons gets bigger and their mean energies increase rapidly.

Key words: bremsstrahlung, backscattered radiation, Monte Carlo method

中图分类号:

O242.2

郭金川, 牛憨笨. X射线在影像增强器中散射特性的研究[J]. 计算物理, 2000, 17(3): 298-306.

GUO Jin-chuan, NIU Han-ben. STUDY OF SCATTERING PROPERTIES OF X RAYS IN INTENSIFIERS[J]. CHINESE JOURNAL OF COMPUTATIONAL PHYSICS, 2000, 17(3): 298-306.