测量1 MA/100 ns脉冲大电流的微分环

强光一号加速器能输出上升沿约100 ns、幅值约2 MA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1.2 ns，频谱响应范围10 kHz~100 MHz，灵敏度为6.1310-11(Vs)/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。 

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

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.