In Star Wars, ion cannons are weapons used to disrupt a target's electrical systems in addition to causing physical damage, essentially functioning as directed electromagnetic pulse weapons.
The most obvious use of an ion cannon occurs in TESB, when a planetary ion cannon at the Hoth Rebel base fires on an Imperial Star Destroyer blockading the planet. Three hits are sufficient to disable the target, causing it to veer off course and allow a Rebel transport to fly past unimpeded. The Star Destroyer takes no visible damage during the incident.
An ion cannon blast on a target can fry the electronic circuitry of the target, requiring the equipment to be repaired. A droid's memory may be wiped if it is affected by ion cannon fire. Eventually, a starship hit by repeated ion cannon fire will lose power. Of course, the energy contained in the ion cannon bolt can still cause physical damage upon impact. Fighter-sized starships have been destroyed upon being hit by planetary ion cannons blasts.
Use in Standard Combat
Ion cannons are used alongside turbolasers in many battles. Ion cannons assist in overcoming enemy shields and disrupt the target's electronic systems more quickly than unassisted turbolasers would.
Properties Against Shields
Ion cannons are blocked by particle shields, but will pass through ray shields. In practice, this means that a target's combat shields must be defeated before any significant effect on its electronic systems takes place.
Ion Cannons outside Star Wars
Outside of Star Wars, ion cannons tend to function like simple energy weapons.
- In Command and Conquer, the Global Defense Initiative makes use of orbital ion cannons as a strategic weapons.
- In Homeworld, ion cannons are heavy anti-capital ship energy weapons that are powerful, but very large. Frigates are built around a single, spinal-mounted ion cannon.
- In Stargate, the Tollan use ion cannons as planetary defense weapons.