Null field matrices
These mechanisms were developed during the War in Heaven and installed on many Tomb Worlds in order to shield them from psychic disturbances. These matrices require an immense amount of power to function and their delicate construction means that they are sheltered in the heart of a Tomb World to protect them from being destroyed. They function by emitting an energy that disrupts a Psyker's connection to the Warp and thus preventing them from utilising their full power. Creatures of the Warp such as Daemons also suffer from their effects, as their bodies flicker in and out of reality as they are unable to maintain a solid hold in realspace. In late M41, they have proven to be equally effective in destabilising the link the Tyranids have to the Hive Mind.