Why isn't the electronics in an EMP gun destroyed when it is fired? Why isn't the electronics in the EMP gun destroyed along with the surrounding electronics? I have been researching electro-magnetic pulses and am confused with how the electronics inside such a gun aren't affected. And as a side question; could an EMP gun direct its EMP by putting aluminium foil on the sides? (I'm not a scientist :D)
 A: You need a credible link to or citation of the technology you seek to learn about for a good answer here. My only knowledge of EMP is as a side effect of nuclear weapons. However, there is a very simple way to make this kind of generator work without damaging its own electronics and that is simply to use a directional antenna. Look up the physics behind the directionality of antennas. A high power electromagnetic pulse would simply be launched using a dish antenna using a Cassegrain launch arrangement; such dishes can easily be built such that the power radiated backwards is many orders of magnitude (typically 6 or 7) below that directed forward. The control circuitry for the device would be housed behind the launch antenna.
One can also design highly shielding conducting cases for electronics, and a sound electromagnetic interference analysis could also formulate a design for casing that could withstand the radiation from the device. But the device would need to be directional anyway, so you would exploit the directionality spoken of above to shield your electronics.
