A solar ionization reactor
A Solar ionization reactor was a kind of hypermatter annihilation reactor which created energy by utilizing hypermatter to form a small star inside the reactor chamber. Specifically, the I-a2b solar ionization reactor model was a common piece of equipment on board TIE/ln space superiority starfighters.
The Star Destroyers of the Imperial-class used by the Galactic Empire were fitted with these reactors. Likewise, the fleet of the Sith Eternal's Xyston-class Star Destroyers of the Final Order also used them.