Measurement of transient electric-fields emitted from micro-gap ESD in spherical electrodes by using optical electric-field sensor

A fast-transient electromagnetic field is emitted by an electrostatic discharge (ESD) event. The field caused by an ESD often gives a serious impact on electric/electronic equipment/facilities. Especially, a micro-gap discharge below 1 kV produces broadband electromagnetic noises of which frequency is more than several gigahertz. Therefore, we investigate an emission mechanism of transient electromagnetic fields due to the ESD event by using spherical electrodes. In this paper, the electric-field waveforms were measured using an optical electric-field sensor to elucidate the mechanism of the ESD event. As a result, we concluded that the measured electric-field represent a feature of as including a quasi-static field, an inductive field, and a radiation field. It was confirmed that the mechanism of electromagnetic emission caused by the ESD in spherical electrodes could be explained as a dipole-radiation model. © 2018 The Institute of Electrical Engineers of Japan.