基于PLC自动搜频AFC系统研究

摘要

Automatic frequency control (AFC) system is one of key systems of electron linear accelerator. However, the strong frequency mutation of the magnetron or the effects of temperature is likely to cause the magnetron frequency offset, which will lead to the failure of the AFC system and a sharp decline of accelerator dose rate. In order to overcome the existing problem of the current AFC system, an AFC system with the function of automatic frequency search was designed according to the feedback signal of magnetron tuning location and dose rate. The experimental results show that the system can effectively prevent the frequency offset and maintain the maximum output of accelerator dose rate.%自动频率控制(AFC)系统是电子直线加速器关键系统之一,由于磁控管强烈的频率突变或温度对它的影响极易造成磁控管频率偏移,导致AFC系统失效,并使加速器剂量率急剧下降.为克服现有AFC系统存在的问题,本工作根据磁控管调谐位置和剂量率反馈信号研究设计具有自动搜频功能的AFC系统.实验结果表明,该系统可有效防止频率偏移,维持加速器最大剂量率输出.