The electromagnetic pulse from nuclear detonations

Abstract

Models of the processes whereby a nuclear detonation emits a coherent electromagnetic pulse fall into three classes: those involving Compton electron currents produced by interaction of prompt γ radiation from the detonation with the environment, those involving photoelectron currents produced by the similar interaction of primary X radiation from the detonation, and those involving perturbation of the ambient magnetic field by the expanding plasma surrounding the detonation point. For each model considered the cause of the asymmetry in the current system necessary for the radiation of a signal is discussed. These causes include the earth‐atmosphere interface, the atmospheric density gradient, anisotropy of the environment by virtue of the presence of the earth's magnetic field, nonuniform emission of the energetic radiation (γ and X rays) by the detonation, and asymmetries of the delivery vehicle and device case. The available experimental data are then examined in the light of the models. These data suffice to establish the models as probably being correct in their identification of the principal processes whereby the nuclear electromagnetic pulse is generated, but they are inadequate for a quantitative assessment of the accuracy of the models.