EMI sources, transients related to lightning and EMP

The electromagnetic pulse (EMP) produced by the detonation of a nuclear explosive is a large, fast rising transient generated by the interaction of gamma radiation and Compton recoil electrons with atmospheric air molecules aid the geomagnetic field. If a vital system has to survive from the effects of a blast in the source region of surface magnetic fields, it has also to survive from the strong electric and magnetic fields present in that region. Moreover, the large transients will conduct on the long transmission and telephone lines which are passing through the deposition region of the radiation region of a surface burst to a larger distance and these conducted transients will be of sufficient amplitude to damage the connected equipment even if they are very far off from the ground zero level of the burst. Besides, the low frequency magnetic field also poses a formidable threat to the equipment/systems present in the source region. The severity of this magnetic field is not only of concern to the systems on the ground but also to the underground systems