摘要
工业用计算机断层扫描技术,简称ICT (Industrial Computed Tomography),是一种无损检测技术,能够在不破坏物体结构的情况下重建物体特定层面的二维或三维图像,具有直观、准确的特点,被称为当代工业领域最佳的无损检测手段。CT技术最初于1917年由Randon J提出来的,直到20世纪70年代中后期才开始大量应用于工业无损检测领域,并随着计算机技术和探测器技术的进步而迅速发展,目前已经成为一种实用化的无损检测手段,广泛应用于航空、航天、航海、核能、军事、石油、机械、海关及考古等多个领域,检测对象多种多样,包括火箭发动机、核燃料、导弹、石油岩心、精密铸件和锻件、集装箱和化石等。
本文主要介绍了工业CT的技术原理及发展路线,对工业CT的各个组成系统进行了详细的分析,并在前人研究的基础上完成了对工业CT物理平台中的X射线源系统、数控系统和探测器系统的搭建工作并结合实际实现了工业CT平台的物理布局及防护设计,主要包括以下研究工作:
(1)分析了现今主要的低能X射线源系统,结合课题需要,有针对性的对所需的X射线源系统参数进行了设定,最终对X射线源系统各组成设备进行了选型。
(2)结合课题开发目标,针对被测物为64mm以下的铝球,对数控系统中的多轴控制器、微型机、电机及伺服驱动器等进行了选型,初步搭建了数控系统。
(3)运用MCNP软件模拟了CsI (T1)晶体在不同条件下的粒子探测效率能量沉积率及有效沉积因子,同时模拟了在不同种类外包反射材料包裹下,一定长度晶体的能量沉积率,根据模拟结果,选择了最佳的外包反射材料;实验模拟的耦合剂对光电二极管响应的影响;最后,分析了闪烁体光电二极管阵列探测器的输出缺陷,并给出其校正原理和最终校正流程图。
(4)对主机房、铅房的平面布局以及通风、电气管道、水管道、高压接地装置等进行了设计,并根据设计结果结合实际需求进行了屏蔽计算。
Industrial Computed Tomography (ICT) Scanning Techniques is a kind of nondestructive testing technology, that can rebuild the two-dimensional or three-dimensional images for a certain level of object structure without breaking the object structure. It has the characteristics of intuitive and accurate, and had been known as the best means of nondestructive testing to the contemporary industry. CT technology was raised in1917by Randon J, it had been widely used in the field of industrial nondestructive testing until in the late1970s,and got the rapid development with the advances in computer technology and detector technology.Nowadays, CT has become a practical means of nondestructive testing, has been widely used in the aviation, the spaceflight, the navigation, the nuclear power, the military, the petroleum, the machinery, the customs, the archeology and the other fields, detection object is varied, including the rocket engine oil, the nuclear, the missile, the core, the precision castings, the forgings, the container, the fossils, etc.
This article mainly introduced the technology principle and development route of industrial computed tomography (ICT),conducted a detailed analysis of the various components of ICT system, and had finished the preliminary design of the ICT physical platform, include the X-ray source system, the CNC system and the detector system on the basis of previous studies, mainly done the following research work.
(1) Analysed of the current major low-energy X-ray source,and made pointed references to set the parameters of X-ray source system to meet the needs of subject, and selected the partial equipment of the X ray source system in the end.
(2) In allusion to the analyte that is a aluminum ball which the diameter is lesser than64mm,we had selected the each partial equipment of CNC system, such as the Multi-axis Controller, the Microcomputer, the Electrical Machiner,the Servo Drive, and so on.
(3) The Csl (TI) crystal of the energy particle deposition rate, the Grain rate of energy deposition and the energy deposition factor effectively which are in different conditions are had been simulated by the MCNP software and had simulated the energy deposition rate when the crystal wraped up different outsourcing reflection material,choose the best outsourcing reflective material. Experimental simulation of the coupling agent effect of the responses of a photodiode. Finally, the paper analyzes the scintillator photodiode array detector output defects, and its correction principle and the final correction flowchart had been given.
(4) The layout plans of the primary machine room and the lead room,and the Ventilation,the electric pipe,the water pipe.the high voltage grounding device had been designed,and had taken the shielding calculation.
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