electron INFORMATION
- Nuclear Weapon EMP Effects.A high-altitude nuclear detonation produces an immediate flux of gamma rays from the nuclear reactions within the device.
These photons in turn produce high energy free electrons by Compton scattering at altitudes between (roughly) 20 and 40 km.
These electrons are then trapped in the Earth;s magnetic field, giving rise to an oscillating electric current.
This current is asymmetric in general and gives rise to a rapidly rising radiated electromagnetic field called an electromagnetic pulse (EMP). Because the electrons are trapped essentially simultaneously, a very large electromagnetic source radiates coherently.
The pulse can easily span continent-sized areas, and this radiation can affect systems on land, sea, and air. The first recorded EMP incident accompanied a high-altitude nuclear test over the South Pacific and resulted in power system failures as far away as Hawaii.
A large device detonated at 400-500 km over Kansas would affect all of CONUS. The signal from such an event extends to the visual horizon as seen from the burst point.