测量1MA/100ns脉冲大电流的微分环

Differential loop for measuring 1 MA/100 ns pulsed high current

"强光一号"加速器能输出上升沿约100ns、幅值约2MA的电流脉冲。实验中通常采用自积分式Rogowski线圈监测负载电流。为与该线圈比对校验,研制了一种快响应、结构简单、抗电磁干扰性能较好的微分环。标定实验给出,微分环测量的响应时间约1.2ns,频谱响应范围10kHz～100MHz,灵敏度为6.13×10-11(V.s)/A。其快时间响应将有助于监测与负载物理特性有关的瞬态电流变化。在加速器二极管短路状态对微分环和积分式Rogowski线圈进行了实验比对,数值积分给出的电流波形与后者基本相符,峰值偏差小于10%,表明微分环的设计合理,同时校验了电流测量的可信度。

The Qiangguang-Ⅰ（QG-Ⅰ） accelerator can produce high current pulses with rise time of about 100 ns and amplitude of about 2 MA.The load current is usually monitored by self-integrating Rogowski coils.In order to verify the obtained results of the coils,a differential loop with fast response time,relatively simple design,and appropriate performance against electromagnetic noise,has been developed.Calibration experiments show that the differential loop has a response time of about 1.2 ns,a response frequency range from 10 kHz to 100 MHz,and a sensitivity of 6.13×10-11（V·s）/A.The fast response may help to monitor transient variation of the load current related to some rapid physical processes.The differential loop has been tested within short-circuit diode of QG-I accelerator and compared with self-integrating Rogowski coils.The current waveforms obtained through numerical integration of the loop signal exhibit good agreements with those from the coils,with an amplitude deviation less than 10%.Comparison of the results confirms the availability of the loop,and also verifies the reliability of the load current measurements on the accelerator.