Level Estimation of Magnetic Far-Field Generated by Spark Discharge Between Charged Metal Spheres

Abstract

The ESD (electrostatic discharge) between charged metals generates transient electromagnetic fields having broadband frequency spectra, which often gives fatal EMI (electromagnetic interference) to high-tech infor-mation equipment. For the EMI of this kind, propagation characteristics of ESD fields in conjunction with electromagnetic coupling between the ESD fields and equipment still remain unknown. From this perspective, we previously proposed an image-dipole method and FDTD methods to analyze the ESD fields due to charged metals. The former method, however, is limited for calculation to the sphere sizes that can keep the equi-potential on the metal surface, and the tatters are unable to analyze the propagation characteristics of the ESD fields over the broad region because of the limited analysis space. In this paper, the feasibility of the above image dipole method was investigated together with the FDTD method by comparing measurement and calculation of the magnetic near-field waveform due to the spark discharge between metal spheres with diameters of 3cm to 10cm. The magnetic far-field peak and its distance attenuation were numerically examined for the spark discharge between the metal spheres.