Design and experimental research of D-dot probe for nuclear electromagnetic pulse measurement

A new conical D-dot probe is designed to measure the electric field wave (rise time less than 2 ns, peak amplitude higher than 50 kV/m) of a high altitude nuclear electromagnetic pulse (HEMP) simulator. The D-dot probe element is introduced in this paper. The design of D-dot is recounted and analyzed. The condition for impedance matching between the D-dot and the transmission cable is analyzed. The configuration and size of probe are confirmed. A signal proportional to the time derivative of pulse electric field is given from the D-dot probe. The electric field is got by a passive RC integrator or a numerical integration. The experiment result proves that the two methods can reconstruct the pulse waveform. The numerical integration is superior to the passive RC integrator. Comparison with the experiment result of the initiative optic transmission measure system indicates that the conical D-dot probe is more suitable for measuring fast rising HEMP signals. (authors)