A medium range energy cannon that delivers an electro-magnetic pulse (EMP) and can quickly disable enemy systems/engines.
The Ion Cannon's nonstandard gain medium projects highly ionized baryonic matter in a coherent bolt. When the ion bolt impacts the target it creates a localized magnetic field which plays havoc with all manner of electronics, including sensors, fuel igniters, targeting modules, computers, etc. The weapon also fuses certain circuits, and can mildly strain shield generators, thus it does negligible amount of permanent damage. Rarely the only weapon type fitted on ships.