Data Aacquisition Of High-resolution X-ray Area Array CCD Detector

CT technology makes significant development in all sectors especially industry and medical industry. It can not only clearly and accurately rebuild the internal structure of the object,but also give material composition and geometry of the internal details quantitatively.The system of detector's data-acquisition is an important part of CT equipment.It can transform X-ray to digital signals.They can be transmitted to the computer in preparation for subsequent processing and reconstruction of image.With the development of science and technology.Requirement of detector's accuracy is also increasing.The detectors can be divided into scintillator detector and gas detector which are commonly used.CCD detector is one of the scintillator detectors.It has a high resolution,wide dynamic range and high sensitivity.Its application is more widely in micro-nano CT system.Therefore the research of data acquisition system of area array CCD detector has great significance.Hardware and software designs of data acquisition system of area array CCD detector are completed based on the requirements of the project and the principle of CCD. First, it analyses and determines the final data acquisition method which is based on the FPGA.It makes a reasonable selection of main devices of all modules in the system.Then, the circuit design of the CCD sensor module is completed through the study of application requirements of area array CCD sensor KAF-8300.It makes a chip of EP1C3T144I7 as timing control device which is producted by Altera so that the timings of the drive signals can meet the requirements. Finally,it designs signal conditioning module,A/D converter module,data caching and uploading module according to the output characteristics of CCD signals.Signal conditioning module makes a process of amplification and filtering for the CCD output signals.A/D converter module makes a process of correlated double sampling, amplification and analog-digital conversion.Data caching and uploading module makes digital signals stored in the RAM and uploaded to the computer through the network interface.It makes a presentation of the joint commissioning in the last part. It mainly includes tests of CCD output signals,data acquisition and transmission in the system.It acquires data of CCD output signals under different light conditions in the process of data acquisition and transmission.The result of the analysis shows that the system is working properly.