Development Of Scanning Magnet Power Supply In Beam Scanning System

Because the absorption degree of the radiated electron beam is different between the surface part of the material and the internal defect part,the image formed at the surface image acquisition interface of the irradiated object is also different,if the tested material is irradiated to different degrees,then the image data obtained are processed,the internal structure parameters of the material can be obtained,which plays an important auxiliary role in material quality inspection and secondary processing.At the same time,in order to prevent the target nucleus from damage caused by electron beam irradiation for a long time,the beam spot is usually scanned and bombarded by deflecting magnetic field.The scanning magnet power supply is an important part of the beam scanning system.The high-energy electron beam can achieve the purpose of scanning radiation on the material through the uniform radiation of the scanning magnetic field.Therefore,a triangular wave scanning magnet excitation power supply is designed in this paper.First of all,the paper analyzes the scanning principle of the scanning magnet power supply in the beam scanning system,and selects the triangular wave as the scanning waveform by comparing the advantages and disadvantages of all kinds of waveforms.Secondly,three methods of modulating triangle wave current are introduced.According to the comparison of three modulation methods,the triangle wave is modulated by inductor linear charge and discharge,and the theory of inductor charge and discharge is described in detail.The inverter circuit is simulated and analyzed by MATLAB simulation software,and the linearity of triangle wave under different frequency and duty cycle is compared.Then the hardware circuit structure of scanning magnet power supply is analyzed in detail,the design of main circuit,control circuit and filter inductor are realized respectively,and the corresponding design parameters and circuit schematic diagram are calculated and designed.The RS485 communication technology is used in the monitoring part,and the Labview host computer is used in the PC to monitor the changes of frequency and voltage in real time.Finally,a continuous triangular wave radiation accelerator scanning magnet power supply device with a peak-to-peak output current of 28 An and a scanning frequency of 20?50Hz is developed.The feasibility of different frequency modulation of scanning magnet power supply under the same load is verified by testing.finally,the working conditions of scanning magnet power supply are determined and the stability of triangular wave generated by scanning magnet power supply is shown.The scanning magnet power supply designed in this paper provides technical support for the beam scanning system to determine the internal defects of materials,and provides the necessary theoretical basis and technical guarantee for the design and application of industrial material defects and beam scanning system.