Containment Field
From Starbase 900 Wiki
A specially shaped forcefield used to isolate dangerous materials like antimatter or biohazard specimens. Containment fields are used in antimatter storage pods to protect a ship against contact with the extremely volatile antimatter. Somewhat different containment fields are used for quarantine isolation and for containment of dangerous biological specimens. The containment fields used in the warp drive on the old Enterprise needed to be phase locked within three percent in order to avoid instability, but by the time of the Enterprise-D, multi-phase containment fields were able to operate considerably above that value.