High-AltitudeElectromagnetic Pulse (HEMP) HEMP is an electromagnetic energy field produced in the atmosphere by the power and radiation of a nuclear explosion, and that is damaging to electronic equipment over a very wide area, depending on the design of the nuclear device and altitude of the burst.
HEMP is produced when a nuclear weaponis detonated high above the Earth’s surface,creating gamma-radiation that interactswith the atmosphere to create an intenseelectromagnetic energy field that is harmlessto people as it radiates outward, but whichcan overload computer circuitry witheffects similar to, but causing damage muchmore swiftly than a lightning strike.
The HEMP effect can span thousands ofmiles, depending on the altitude and thedesign and power of the nuclear burst.and can be picked up by metallicconductors such as wires or power cables,acting as antennas to conduct the energyshockwave into the electronic systems ofcars, airplanes, and communicationsequipment.
High-Power Microwave (HPM)(HPM) is an electromagnetic pulseproduced with special equipment thattransforms power from batteries, or from achemical explosion, into intense microwavesthat are very damaging to electronics withina much smaller area.
while HEMP weapons are large in scale andrequire a nuclear capability along withtechnology to launch high altitude missiles,HPM weapons are smaller in scale, involve amuch lower level of technology, and maybe within the capability of many non-stateorganizations. HPM can cause damage tocomputers similar to HEMP, although theeffects are limited to a much smaller area.
HPM is a non-nuclear radio frequencyenergy field. It can be produced as aweapon when a powerful chemicaldetonation is instantly transformed by aspecial coil device, called a flux compressiongenerator, into a strong electromagneticfield of microwave energy. Other methods,such as powerful batteries, can also be usedto create a reusable HPM weapon. HPMenergy can be focused using a specially-shaped antenna, or emitter, to produceeffects similar to HEMP, but only within a verylimited range.
Unlike HEMP, however, HPM radiation iscomprised of shorter wave forms at higher-frequencies, which make it highly effectiveagainst electronic equipment and moredifficult to harden against.
A mechanically simple, suitcase- sizeddevice, using a chemical explosive andspecial focusing antenna, mighttheoretically produce a one-time,instantaneous HPM shockwave that coulddisrupt many computers within a 1-milerange.
technical accessibility lower cost the apparent vulnerability could cause physical harm to persons near the source emitter, or possibly in the path of a narrowly focused energy beam at higher power levels (megawatts).