Tachyon Field (SMAC)

is a base facility in Sid Meier's Alpha Centauri. The Tachyon Field increases the base defense modifier by an additional 100%, in addition to the 100% provided by its prerequisitely built Perimeter Defense. Unlike Perimeter Defenses, however, it increases the modifier for all areas of combat; land, sea, and air. Thus, a base with both a Perimeter Defense and a Tachyon Field has its effective defensive ability tripled against land units, and doubled against air units (or tripled if the base also has an Aerospace Complex.
It requires Probability Mechanics to build. Like any other base defense system, however, it can be bypassed by units bearing the Blink Displacer ability.