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How does a nuclear electromagnetic pulse damage electronic equipment?

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U.S. hydrogen bomb test in the Marshall Islands — nuclear weapon A test of a U.S. thermonuclear weapon (hydrogen bomb) at Enewetak atoll in the Marshall Islands, November 1, 1952.

A nuclear electromagnetic pulse (EMP) damages electronic equipment primarily by inducing sudden, high-voltage electrical currents and voltages within the devices' internal circuitry.12

This phenomenon originates from the gamma radiation released during a nuclear explosion. When these gamma rays collide with air molecules, they trigger the Compton effect, which ejects high-energy electrons. This process separates positive and negative charges in the atmosphere, creating a massive electric field. Asymmetries in this field—influenced by factors like altitude and air density—generate time-varying electrical currents that manifest as an EMP.12

When this pulse interacts with unprotected electronics—such as computers, radios, and communication systems—it acts like a surge, overwhelming sensitive components with induced currents. This can cause immediate failure or permanent damage to the equipment. To mitigate these risks, military systems often undergo a process called "hardening," which improves their ability to withstand such electromagnetic interference.12