Psi block

The psi block is a Terran Dominion technology designed to use sigma radiation to slow the speed and reaction time of nearby zerg organisms. Its design was based off of the psi disrupter research of the United Earth Directorate.

Psi blocks were first deployed in 2512 during the One-Day War on Gystt, where an expedition of Terran Dominion forces sent to investigate the planet were given use of the devices. While they were able to slow down zerg forces, they also blocked communications, and did not seem to be effective against chitha that they were forced to engage.