Using a Second-Order Integral Equation Method to Study the High-Altitude Nuclear EMP

A zero-order integral equation method (IEM) in our former report was introduced to simulate the high-altitude electromagnetic pulse (HEMP). The planar gamma source model was employed and results of the zero-order IEM matched those of the outgoing wave method (OWM). In this paper, a second-order IEM is introduced for the calculation of the HEMP. The point gamma source model is employed and the modified space and basis function decomposition are introduced. The partial derivatives of the current densities are calculated by the least square method. The results show that the fields and currents calculated by the OWM and the second-order IEM are in good agreement. Both the first-order IEM and the second-order IEM are converged. The second-order IEM is more complicated but more accurate than the OWM.