虚拟负载在瓦里安加速器高压脉冲调制系统故障维修中的应用研究

瓦里安加速器高压脉冲调制系统是通过PFN电容充放电产生高压负脉冲,在高压脉冲调制系统放电过程中,必须使得速调管的等效负载RL等于PFN的特性阻抗R0。当系统出现故障,等效负载RL小于PFN的特性阻抗R0,终端削峰电路的电流互感器检测到反向电流,就会产生MOD连锁故障。文章分析了医院瓦里安21EX型加速器高压脉冲调制系统工作基本理论,通过使用虚拟负载准确定位MOD连锁故障点,总结出排查类似故障的分析和判断方法,使医院能够自主维修加速器高压脉冲调制系统的MOD连锁故障,减少因MOD连锁故障引起的停机时间和维护费用,提高加速器的工作效率和运行绩效。

The modulation system of Varian generated high negative voltage pulses through the charge and discharge of the PFN capacitor.During the discharge process of modulation system,the equivalent load RL of the klystron must be equal to the characteristic impedance R0 of PFN.When the equivalent load RL is less than the characteristic impedance R0 of PFN and the current transformer of the end clipper circuit detects reverse current and then produces MOD I/L.This paper analyzes the basic theory of modulation in the process of charging and discharging process,uses virtual load to accurately locate MOD I/L fault points,and summarizes analysis and judgment methods of troubleshooting similar faults,so that the hospital can independently maintain the MOD I/L faults of accelerator high voltage pulse modulation system,reduce downtime and maintenance costs caused by MOD I/L failures,and improve the work efficiency and operational performance of the accelerator.