ABSTRACT
This chapter discusses the initial nuclear radiation is the cause of some of the electromagnetic effects. The temperatures reached in fission explosives are sufficient to ignite thermonuclear reactions. The original intent was to detonate the nuclear explosive in the air several hundred meters above the ground. Because the close-in equipment was bunkered to shield against air blast, heat, and nuclear radiation, it was conjectured that electromagnetic effects were driving large currents in the wires entering the bunkers. A characteristic transient electromagnetic pulse was indeed routinely observed by placing vertical high frequencies antennas at large distances. The aggregate of streaming Compton electrons in unit volume constitutes an electric current density, which is the source of electromagnetic fields. The chapter discusses the known basic physics involved in the effects and magnitudes that can be estimated therein, using nominal outputs of nuclear explosions. For a nuclear explosion in the atmosphere at any altitude, the fireball and the strongly shocked air are electrically conducting.
