X射线机管电流控制方法研究

Research on Tube-Current Control Method of the X-Ray Machine

管电流是X射线机中非常重要的参数,它影响X射线与其它物质的相互作用。本文介绍了在高频开关电源供电情况下X射线机管电流的控制方法;采用管电流自身的负反馈控制、灯丝加热电流的反馈控制以及空间电荷效应的补偿等三个方面来实现管电流的精确控制。该方法既可以实现对管电流的线性控制,还可以实现管电压大范围改变时空间电荷的非线性补偿。文中采用脉宽调制电路实现了上述方法,实验测试了管电流与管电压等多个关系曲线,实验结果显示该方法可行,完全可以推广应用。

Tube-current is the all-important parameter of the X-ray machine; it affects the reciprocity between the X-ray and the others material. The control method of the tube-current is introduced in this paper, which is supplied the high-frequency switched mode power supply. The method can implement the tube-current precision control adopting the current feedback, the filament current feedback and the compensation of the space charge effect. It can realizes the tube-current linear control and nonlinear compensation when the tube voltage varying in large range. The method is designed using pulse modulation circult, measured such as the relationship between tube-current and voltage. The experimental results show the method feasible, and it can be spread.