采用Ir192放射源的数字射线照相技术应用研究

发布时间：2018-01-25 04:14

本文关键词： 计算机射线照相黑度灵敏度检测工艺　出处：《华南理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：为了保证核设施的质量和安全,核电站施工中各部件的制造、安装、役前和在役检查各个环节均离不开射线检验。焊接是建造核设施的重要施工方法,焊接接头的质量对核设施的建造和安装的质量和可靠性有重要影响。在现在的核电建造过程中,主要采用传统的射线照相检验作为检验焊接质量的方法。计算机射线照相(CR)技术是一种射线透照影像的数字采集技术,是近年正在迅速发展的数字射线照相技术中一种新的非胶片射线照相技术。与常规射线照相检测技术相比较,CR技术采用能够存储影像信息的荧光成像板(IP)代替胶片,实现了射线检测图像的数字化,体现了数字射线照相检测的鲜明特点。本文以核电建造期间射线检测的实际应用为前提,研究使用Ir192(铱)放射源的计算机数字射线检测技术在核电建造检测中的应用可行性。黑度是射线检测中尤为重要的参数,在数字底片影像中以图像灰阶值替代了传统的黑度。本文通过设计专用的验证试块,确定了数字射线检测中底的片最佳“黑度”范围,为后续试验奠定了基础。灵敏度是评价射线照相影像质量的最重要技术指标。为了确定CR技术各参数对灵敏度的影响,本文分别从曝光量、扫描精度参数和光电倍增管强度三个方面进行了实验研究。通过实验得出了以上参数的最佳取值范围,为制定数字射线检验工艺提供了依据。最后在制定了数字射线检测工艺的基础上,选择缺陷试块,使用同位素放射源对其分别进行传统射线和数字射线检测,将检测结果进行对比分析,得出了以同位素放射源的数字射线技术的可行性,确定数字射线检测技术能满足现有核电检测标准,为后续开展数字射线系统的现场应用提供了依据。
[Abstract]:In order to ensure the quality and safety of nuclear facilities, the manufacture, installation, pre-service and in-service inspection of various components in nuclear power plant construction can not be separated from X-ray inspection. Welding is an important construction method for the construction of nuclear facilities. The quality of welded joints has an important impact on the quality and reliability of the construction and installation of nuclear facilities. The traditional radiographic inspection is mainly used as the method to test the welding quality. The computer radiography (CRT) technique is a digital acquisition technique for radiographic images. It is a new non-film radiography technology, which is developing rapidly in recent years. It is compared with conventional radiography technology. The CR technology uses the fluorescence imaging board IPs which can store the image information instead of the film to realize the digitization of the radiographic inspection image. This paper is based on the practical application of radiography during the construction of nuclear power. This paper studies the feasibility of the application of computer digital ray detection technology using Ir1922 (iridium) radioactive sources in nuclear power construction testing. Blackness is a particularly important parameter in radiographic testing. The traditional blackness is replaced by the gray scale in the digital negative image. In this paper, the best "blackness" range of the digital radiographic detection is determined by designing a special verification test block. The sensitivity is the most important technical index to evaluate the radiographic image quality. In order to determine the influence of CR parameters on the sensitivity, this paper starts from the exposure. The scanning precision parameters and the intensity of photomultiplier tubes are studied experimentally, and the optimum range of the above parameters is obtained by experiments. Finally, on the basis of the development of the digital ray inspection technology, the defect sample is selected, and the traditional and digital ray detection is carried out by using the isotope radioactive source, respectively. By comparing and analyzing the test results, the feasibility of digital ray technology based on isotopic radiation source is obtained, and it is determined that the digital ray detection technology can meet the existing nuclear power detection standard. It provides the basis for the field application of the digital ray system.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG115.28

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