为测量快脉冲直线变压器驱动源(LTD)二极管负载的脉冲高电压, 设计了在真空环境中使用的电阻分压器。分压器使用绝缘堆结构, 采用静电场模拟分析了分压器的电场分布。建立了包含分布参数的等效电路, 并进行了频率响应仿真, 可得分压器的频响上限为200 MHz。使用标准高压探头对分压器进行在线标定, 分压比标定结果为5 400∶1, 与设计值相符合。在LTD调试实验中, 模块充电85 kV时二极管电压为1.08 MV, 与理论估算结果一致。

A resistor divider has been designed for voltage measurement of diode load for 1 MV/100 kA fast linear transformer driver(LTD). The divider is designed with two stages. The primary stage is a column of alternating annular metal grading rings and tapered insulators enclosing a resistive solution of sodium thiosulfate. A middle electrode is connected to the secondary voltage dividing stage. There is a 4 kΩ resistor in series with the 50 Ω input impedance of the attenuator or oscilloscope. The equivalent circuit of the divider which includes distributed capacitance and inductance has been calculated. It indicates that the high frequency limit of the divider is about 200 MHz. The divider has been calibrated in-situ using a P6015A probe and a high voltage pulser. The calibration ratio is 5 400∶1. The voltage of diode load reaches 1.08 MV when the charging voltage of LTD stage is ±85 kV respectively, according with the simulation of LTD.