数字化线阵CCD扫描X射线成像系统

介绍了一种数字化线阵CCD扫描X射线成像系统的原理性样机,其主要特点是用窄束X射线成像,从系统结构上抑制了散射对成像的影响,在满足图像质量的情况下降低了成像所需的X射线剂量.介绍了系统设计的理论基础,讨论了系统的软、硬件组成,并测量了系统的成像性能.     

药柱内孔的微焦点X射线偏心检测

针对一类特定的微小型药柱,研究了基于正弦图和经验信息,通过微焦点X射线获取三个角度下的X射线投影数据,求解出圆心坐标的方法;从而判断药柱内孔的分布是否偏心,若偏心,则给出偏移量。实验表明,与CT重建结果相比,该方法能够准确地得到圆心坐标,能够满足工业中要求的精度;与经验信息对比,可以判断是否偏心,以及偏移量,为下一步工作转台调整提供参数。     

微焦点X辐射密度解析成像方法及非线性校正

提出了一种利用不同能量的Ｘ射线束所获得的图像来实现分离物体内部不同密度成分图像的方法,从本质上对这种算法进行了探讨,证明了这种算法的可行性;讨论了产生误差的原因,给出了对误差进行非线性校正的数学模型;并以两种成分的图像分离为例进行了实验,给出了实验结果。     

X射线成像系统的非线性特性

通过理论分析和实验研究,探讨了X射线成像系统的非线性特性及其成因,这对于提高X射线成影像的质量具有重要意义。     

X射线面阵列探测器平移扫描分层成像

文章介绍一种先进的移动物品高速准三维成像技术，即利用锥束X射线和面阵列探测器平移扫描(PDTS)，实现移动物品的高速准三维成像。这种成像技术的优点是通过1次简单的平移扫描即可获得物体空间的准三维信息。     

数字化网络化多通道闪光X射线成像系统

介绍了研制的数字化网络化多通道闪光X射线成像系统,它能以正交方式同步获取多瞬时纳秒X射线透视图像。所获取的图像立即数字化和通过网络传送,完全没有胶片系统的冲洗、等待和交流的麻烦,是研究和检测弹道、射流、穿甲、爆炸、喷射和高速运动机械的重要技术。描述了系统的组成和实际测量的绺弹道图像,介绍了自动进行目标分裂、弹道轮廓计算和三维空腔图像重建的效果。     

微焦点X辐射图像分离非线性成像方法研究

实验验证了有机玻璃－铝系统的特性,在微焦点X光机上通过分析不同能量X光束对物体的多次成像,从而分离出物体不同成分的分布图像,以突出显示其中的某种材料。对管电压、管电流、有机玻璃－铝系统的材料尺寸以及误差进行了探讨,对快速图像分离方法提出了改进,给出了数学模型,并展了这种方法的应用前景。     

基于相位衬度成像的X射线生物特征识别仪

海关生物安全检测对维护生态平衡和保护珍稀野生动植物具有重要意义.针对传统海关生物安全检测基于吸收衬度对生物样品成像衬度受限的问题,研制了一种基于相位衬度成像的X射线生物特征识别仪.通过采用光子利用效率高的同轴相衬成像方法进行成像,满足海关检测数据采集效率高和成像快的需求.为保证检测的辐射安全和样品调整方便,采用辐射防护...     

基于CCD-镜头耦合的数字X射线成像系统设计与改进

通过分析现有基于CCD—镜头耦合的数字X射线成像系统存在的缺陷,对系统结构进行了改进,对系统部件进行了优化。实验表明,改进后的系统除了获得良好的空间分辨率和检测灵敏度之外,还降低了正向散点噪声对图像的干扰,系统的成像质量得到明显提高。     

用于高能X射线成像的CdWO4闪烁探测器探测灵敏度的研究

高能X射线成像系统对小截面探测器的探测灵敏度提出了很高的要求,分析了由CdWO4晶体耦合光电二极管所组成的探测器单元探测灵敏度的决定因素,采用蒙－卡计算、经验估算等对其在高能加速器和^60Co源下的探测灵敏度进行了估算,并和测量值进行比较。二者吻合较好,证明了估算方法的正确性。     

A review of geometric calibration for different 3-D X-ray imaging systems

A precise knowledge of geometry is always pivotal to a 3-D X-ray imaging system,such as computed tomography(CT),digital X-ray tomosynthesis,and computed laminography.To get an accurate and reliable reconstruction image,exact knowledge of geometry is indispensable.Nowadays,geometric calibration has become a necessary step after completing CT system installation.Various geometric calibration methods have been reported with the fast development of 3-D X-ray imaging techniques.In these methods,different measuring methods,calibration phantoms or markers,and calculation algorithms were involved with their respective advantages and disadvantages.This paper reviews the history and current state of geometric calibration methods for different3-D X-ray imaging systems.Various calibration algorithms are presented and summarized,followed by our discussion and outlook.     

A characterization study on perovskite X-ray detector performance based on a digital radiography system

X-ray imaging technologies such as digital radiography(DR),is an important aspect of modern non-destructive testing and medical diagnosis.Innovative flexible X-ray detector technologies have recently been proposed and are now receiving increasing attention owing to their superior material flexibility compared with traditional flat-panel detectors.This work aims to study these innovative flexible X-ray detectors in terms of their effectiveness in DR imaging,such as detection efficiency and spatial resolution.To achieve this goal,first,a Monte Carlo model was developed and calibrated to an in-lab 150 kV DR imaging system containing a flat-panel X-ray detector.Second,the validated model was updated with various types of flexible X-ray detectors to assess their performance in nearly realistic conditions.Key parameters such as the detection efficiency pertaining to the crystal material and thickness were studied and analyzed across a broader energy range up to 662 keV.Finally,the imaging performance of the different detectors was evaluated and compared to that of the flat-panel detector in the 150 kV DR imaging system.The results show that the flexible detectors such as the CsPbBr3 crystal detector deliver promising performance in X-ray imaging and can be applied to a wider range of application scenarios,especially those requiring accurate detection at challenging angles.     

μm-resolved high resolution X-ray diffraction imaging for semiconductor quality control

We present a method and an equipment for performing μm-resolved X-ray diffraction area maps, and apply it to wafer defect analysis and industrial wafer quality inspection. The method determines simultaneously the macroscopic warpage, the mesoscopic curvature and the microscopic defect structure of semiconductor wagers. It is based on X-ray diffraction rocking curve imaging of the whole wafer with down to 1 μm² resolution. The new wafer testing equipment determines the maximal and integral peak intensities, the peak position and the half width of the rocking curves with a microscopic resolution, thus imaging simultaneously the macroscopic quality parameters and the microscopic defect structure. This permits to establish a direct one-to-one correlation between the microscopic defects and the resulting macroscopic effects. As an example, wafers of different materials, fabrication technology and resulting perfection are studied. When investigating layered samples, the technique allows furthermore to determine the influence of the wafer quality on the layer properties. The method can be applied generally to characterize non-destructively the quality of all kinds of crystalline structures, like, e.g. microelectronic and optoelectronic devices.     

基于微机的多参数核物理实验数据获取分析系统

介绍一台由微机控制的用CAMAC插件组成的多参数数据获取和离线数据分析系统。该系统采用软件控制的方法进行信号种类的甄别以及划定信号收集的范围。与用NIM系统构成的数据获取系统相比,在达到同样测量精度的基础上,降低了对硬件设备的要求。该系统再配合微型电离室、芪晶体探测器,被用来做裂变中子飞行时间谱的测量,给出了测量结果。     

移动式大型集装箱检测系统图像的矫正与放大研究

介绍了移动式大型集装箱检测系统图像的几何矫正的算法,给出了矫正前后图像的比较分析,并讨论了图像放大的算法。由于这些算法的采用,图像质量得以提高。