The Design Of Quick Detection And Data Acquisition System Base On Low-energy X-Rays

Industrial CT (ICT) is an important industrial Non-Destructive testing method, which could through two-dimensional ct images form intuitively and clearly display the structure characteristics, composition, material and defects of the objects to be detected in the noninvasive cases, it has been widely used in industrial product testing, and it is one of the most advanced detection means currently.Low-energy X-ray CT system mainly used in medicine,security and small medium size workpiece inspection line etc. As CT technology constantly improved, the requirements of CT equipment performance are more and more high, but the performance of existing low-energy X-ray CT equipment is poor, generally existing low detection rate,not high image quality and not strong reliability. For the issues in the low-energy X-ray CT system, this paper proposed the quickness low-energy x-rays detecting acquisition system based on the low-energy X-ray, study the aproach which can improve the scanning velocity and imaging quality of the system, from the quickness of the system.Signal detection acquisition system is an important component of the industrial CT part, mainly completes collection,conversion of the X-ray signal, and upload the converted data to host computer to carry out image reconstruction through the data transmission system. This design uses the ideas of modular design, divided the signal acquisition system into detector module,signal conversion module and acquisition control module three modules, the advantages of using this kind of structure is to increase the flexibility of the system, convenient the expansion of the system. Detector module mainly used to achieve conversion of the X-ray signal photoelectric, which used photoelectric diode scintillation detectors. Signal conversion module implements the amplification of the integral and conversion of the modulus, this module mainly achieve through the A/D conversion chip DDC316, DDC316 is 16 bits, 16 channel of the A/D converter which is launched by TI company, it has the characteristics of short time integral,small capacitance integral,high rate of transmission data. Acquisition control module is mainly used to control detecting collection of signal acquisition system and to sent the data collected to data transmission system required, the master chip of the control module choose FPGA which has strong parallel processing ability.This design mainly includes hardware circuit design and logical control design. Hardware circuit design mainly to complete through auxiliary software of Protel DXP, logic control design adopts the design ideas of top to down, adopts Verilog HDL language program, and compiles,comprehensive and simulation of the software program with QuartusⅡ, eventually system and transmission system and PC joint debugging.Through the tests, the results show that the system has good performance, can accurately, fastly realize the acquisition transmission data, achieve the expected effect of the systm design.