Here is an image depicting an ion charge being discharged from the Naboo Royal Starship.
An ion charge was a type of missile that contained an ion payload. It was generally deployed to penetrate and incapacitate the defensive systems of enemy targets.
During their assault targeting Cylo's research base, both Aphra and Darth Vader made use of an ion charge. Specifically, Aphra launched the ion charge from Vader's J-type 327 Nubian, which then generated an ion blast within the base's control room, effectively disabling its circuits, doors, and communication systems.