B-Dot and D-Dot Sensors for (Sub)Nanosecond High-Voltage and High-Current Pulse Measurements

Abstract

In this paper, we present a large-bandwidth, high-current, and high-voltage measuring system for pulse measurements in pulsed power systems. The developed sensors can be easily calibrated, require no extensive (3-D) modeling, are very compact, are inexpensive, and have a bandwidth of up to several gigahertz. Moreover, they can be used in any pulsed power system, where a pulse source is connected to its load by a coaxial cable (without disturbing the coaxial geometry). We developed this sensor system for the use with our nanosecond pulse source system. The type of sensors we used is D-dot and B-dot sensors, which are compactly mounted on the coaxial cable that connects our nanosecond pulse source to its load. This enables us to measure the characteristics of each sensor very precisely with a vector network analyzer. With these characteristics—combined with the characteristics of the measuring cable assembly—we can numerically reconstruct the voltage and current waveforms that passed the sensor positions. Our calibration approach, the mounting on the coaxial cable and the postprocessing of the results makes these sensors very flexible. While we use the sensors for energy measurements, camera triggering, and the general measurement of the pulses, other researchers can use these types of sensors as well in any system, where a (coaxial) cable connects a pulse source to its load.