Small X-ray Screening Instrument Signal Acquisition And Processing Technology

At the present time, the X-ray flying-spot scanning system is a new technology. Based on the Compton effect and photon absorption effect, the system can achieve the double energy transmission (including high energy and low energy) and backscatter detection simultaneously.The study bases on the transform of the low signal which is the output of the detector. The result of the transform can be disposed by the subsequent circuit. The choice of the acquisition mode which includes logarithm, exponent and linearity operation, the valid digit of ADC, the time of the signal acquisition and the pixel amount may determine the definition of the image. The main acquisition parts of the system consist of precimplifying circuit and clock circuit.The preamplifying circuit transforms the analog signals into digital signals which are compatible for the disposition of the subsequent circuit. The results of the disposition are passed to the image capture card. The clock circuit receives the row signal and the wheel signal from the sensor of the chopping wheel system and generates the control signal for the acquisition system.During the debugging of the whole system, the logarithm operation is adopted to the transmission system for its low energy, and linearity operation to the backscatter system for its high energy. With the choices we can get satisfying images.