狭缝法测量X射线管焦点尺寸的研究  

Research on Slit Method for Measuring Focal Spot Size of X-ray Tube

作　　者：李伟伟 王立强[1,2] 郑健 LI Weiwei;WANG Liqiang;ZHENG Jian(Institute of Nuclear and New Energy Technology,Tsinghua University,Beijing 100084,China;Beijing Key Laboratory of Nuclear Detection and Measurement,Beijing 100084,China)

机构地区：[1]清华大学核能与新能源技术研究院,北京100084 [2]北京市核检测重点实验室,北京100084

出　　处：《原子能科学技术》2024年第2期498-505,共8页Atomic Energy Science and Technology

摘　　要：目前EN 12543标准中的狭缝法广泛应用于工业用X射线管焦点尺寸的测量和标注。然而所需的测试设备——狭缝相机,由于其复杂和精密的设计要求,导致生产加工难度大、成本高且不利于推广使用。本文采用双钨合金圆柱代替狭缝相机,基于圆柱法中距离和位置参数校准方法,改进了狭缝法中焦点尺寸测量的计算公式,研究了不同狭缝大小对X射线管焦点尺寸测量的影响和变化规律。实验结果表明,使用间距与焦点尺寸相当的双钨合金圆柱测量COMET公司的MXR-225HP/11工业X射线管,也可以获得较为精确的测量结果,同时实验发现当狭缝宽度较大时,可以直接用来计算焦点测量装置的几何放大倍数,并且计算结果与圆柱法中使用距离和位置参数校准方法所测量的结果相一致。The focal spot size of X-ray tube is one of the key factors affecting the imaging resolution,and it is also an important index to characterize the working performance of the X-ray source.Typically,after the X-ray tube is manufactured,the focal spot size must be measured and marked.Nowadays,the most widely used measurement standards for X-ray tube focal spot size in the world are IEC 60336,EN 12543,and ASTM E1165.Between various standards,there are differences in the focal spot size measurement methods,scope of application,loading factors and imaging equipment.Among these,the slit method of EN 12543 standard is mostly utilized in industrial X-ray tubes.However,due to its complex and precise design requirements,the test equipment,i.e.,the slit camera,is difficult to produce and process,and the cost is high,which is not conducive to promotion and application.This paper studied the influence and variation of the measurement of the focal spot size at different slit sizes by using double tungsten alloy cylinders instead of slit camera.Based on the calibration of distance and position parameters in the cylinder method,the measurement equipment was conveniently positioned,and the distance between the focal spot and the translation mechanism was measured simultaneously,which improves the position accuracy of the focal spot size measurement.Additionally,the formula for determining the focal spot size in the slit method was improved,so that the slit method can be applied to a wide range of slit widths.In particular,the geometric magnification of the system can be measured directly when the slit width is large,skipping the step of measuring the distance between the focal spot and the translation mechanism.The experiment scheme has low requirements on the centering conditions of the equipment and the distribution of the X-ray source.In the data processing process,dark field correction and bright field correction were used to eliminate the problem of inconsistency in the response characteristics of each detector pixel,and the

关 键 词：X射线管 狭缝法 圆柱法 焦点尺寸 

分 类 号：TL99[核科学技术—核技术及应用]