Sensitivity Analysis of Conductivity Models in Simulation of High-Altitude Electromagnetic Pulse

The reasonable conductivity model and parameters are important for the accurate simulation of high-altitude electromagnetic pulse. While in most public literature, the fitting formulas of the conductivity parameters are given directly without discussion of their physical meaning. In addition, few investigations were carried out in systematic analysis on the parameter sensitivity of the air conductivity model. In this article, the sensitivity of the parameters in the equilibrium ohmic model is analyzed, indicating that electron mobility is the most sensitive conductivity parameter. The law of the peak electric field with the electron mobility under different conditions of observation direction, burst height, yield, gamma energy, and gamma pulse waveform is systematically explored. It is concluded that a reasonable mobility fitting formula should consider the effects of air density, electric field intensity, and nonequilibrium effect, and the fitting result should be as close as possible to the credible measurement value.