Antimatter constrictor coil
An antimatter constrictor coil was a vital component of warp cores on  vessels in the 2150s.

In 2154, an illusion of T'Pol told a halluncinating Phlox that the antimatter constrictor coil was online when Phlox planned to take  to warp speed while the ship was inside a trans-dimensional disturbance. ()
Warp