Microfusion chamber

From Memory Alpha, the free Star Trek reference

A microfusion chamber is an device that generates energy.

Trajis Lo-Tarik, a hallucination created in Seven of Nine's mind when the USS Voyager was traveling through a radioactive Mutara-class nebula in 2374, asked for a microfusion chamber. He was willing to offer liquid helium in return. (VOY: "One")