The Son'a metaphasic collector was a massive spacecraft designed by the Son'a for the specific purpose of harvesting metaphasic radiation from the rings of Ba'ku. The collector was designed to launch an injector which would produce a cascading reaction within the ring, allowing the collector to harvest the radiation that emanated from them. A major side effect of this process, however, was that the planet would be rendered uninhabitable.
The collector was disabled moments before it could launch the injector when Jean-Luc Picard, Worf, and Subahdar Gallatin comandeered Ru'afo's ship and deactivated the collector. However Ahdar Ru'afo managed to transport aboard the collector shortly thereafter. Picard managed to beam aboard and activate the collector's self-destruct sequence. Picard was beamed away seconds later by the USS Enterprise-E, but Ru'afo was killed when the collector exploded. (Star Trek: Insurrection)