基于双丝型像质计测定射线照相检测系统性能

打开文本图片集

中图分类号：TG115. 28 文献标识码：A

doi：10. 37188/OPE. 20253307. 1051 CSTR：32169. 14. OPE. 20253307. 1051

Determining performance of radiographic examination system with duplex-wire type image quality indicator

YANG Qingguo*，TAN Bozhong，HE Xiaozhong，TANG Ruo，YANG Liu，LIAO Shuqing， SUN Yunfei，MA Chaofan，DENG Jianjun

（Institute of Fluid Physics，China Academy of Engineering Physics，Mianyang ，China） * Corresponding author， E -mail：yungore@163. com

Abstract：Current international standards restrict the use of the duplex-wire type IQI to evaluating basic spatial resolution，leaving its broader potential underexplored. This study seeks to extend the application scope of the duplex-wire type IQI by proposing novel methods for assessing radiographic system perfor⁃ mance. Initially，a theoretical imaging model of the duplex-wire type IQI is developed，facilitating deriva⁃ tion of a formula for calculating the image contrast transfer function（CTF）and comprehensive analysis of the effects of IQI placement，radiation energy，and line spread function（LSF）. Subsequently，the leastsquares method is employed to estimate the CTF，enabling calculation of the LSF and modulation transfer function（MTF）. Integration with an improved Akima interpolation method permits more precise mea⁃ surement of the system's basic spatial resolution. Furthermore，the duplex-wire type IQI is utilized to cali⁃ brate the detector and characterize the focal spot shape of the radiation source，as well as to predict the

LSF and MTF across varying imaging magnification ratios. The proposed approach has been rigorously validated using a 9MeV micro-focus petal CT system and a 300kV micro-focus industrial CT system de⁃ veloped in China. Experimental results demonstrate that the duplex-wire type IQI serves not only in mea⁃ suring basic spatial resolution but also plays a critical role in quantifying the CTF，LSF，and MTF of radi⁃ ation sources，detectors，and imaging systems，thereby offering a effective way for comprehensive perfor⁃ mance evaluation of radiographic inspection systems.

Key words：radiographic examination；duplex-wire type image quality indicator；contrast transfer func⁃ tion；line spread function；modulation transfer function；focal spot measuring；petal CT system

1 引 言

射线照相检测是无损检测领域的重要分支，凭借它能够检测工件内部的几何结构缺陷、获取缺陷直观图像，且定性准确、部分情况下还可对缺陷特征尺寸进行定量测量的优势，在航空航天、机械制造、石油化工等众多行业得到了广泛的应用［1］。（剩余18018字）