![MAIS display](https://cdn.statically.io/img/static.wikia.nocookie.net/memoryalpha/images/a/a2/MAIS_display.jpg/revision/latest/scale-to-width-down/180?cb=20160710194127&path-prefix=en)
The system displayed on a monitor of the Enterprise NX-01
![USS Jenolan's warp propulsion system display](https://cdn.statically.io/img/static.wikia.nocookie.net/memoryalpha/images/4/45/USS_Jenolan%27s_warp_propulsion_system_display.jpg/revision/latest/scale-to-width-down/180?cb=20190410030534&path-prefix=en)
M/ARC of the USS Jenolan
![MARA access tube](https://cdn.statically.io/img/static.wikia.nocookie.net/memoryalpha/images/f/f7/MARA_access_tube.jpg/revision/latest/scale-to-width-down/180?cb=20090208071636&path-prefix=en)
Access crawlway to the M/ARA of a Constitution-class starship
![Dilithium crystals](https://static.wikia.nocookie.net/memoryalpha/images/0/0b/Dilithium_crystals.jpg/revision/latest/scale-to-width-down/180?cb=20120728222644&path-prefix=en)
Part of the dilithium articulation frame from a M/ARA
A matter/antimatter reaction assembly (often known simply as an M/ARA) was a type of energy reactor which was fueled by injectors of matter and antimatter into a central reaction element, creating large amounts of energy when those two materials mutually annihilated each other. Matter and antimatter were injected into the M/ARA in an intermix ratio. The dilithium crystal is used to moderate this reaction. These types of power plants were commonly used as warp cores. (TNG: "Coming of Age")
On Constitution-class starships, the dilithium crystal converter assembly was a separate unit from the intermix chamber. It consisted of the matter/antimatter integrator or reactor which channeled the reactor energy to the dilithium crystal converter assembly to be energized into warp plasma for the warp engine nacelles. (TOS: "That Which Survives", "Elaan of Troyius")
The dilithium articulation frame was housed inside the M/ARA behind the dilithium chamber hatch. (TNG: "Skin Of Evil", "The Drumhead")
On monitors it was also displayed as the matter/antimatter input system, (ENT: "The Catwalk"), the matter/antimatter reaction chamber (TNG: "Relics") or the matter/antimatter reaction system. (PIC: "Dominion")
The prototype Jem'Hadar battleship had a fatal design flaw; the braces holding together the ship's M/ARA were vulnerable to a specific type of radiation. The crew of the USS Valiant believed they could use this flaw to their advantage when they were plotting the ship's destruction in 2374. (DS9: "Valiant")
In 2368, after the computer systems of the Enterprise-D were disrupted by a energy wave from a Satarran starship, Geordi La Forge accessed the basic system directories of the engineering department. According to the department, the matter-antimatter reaction assembly was off-line. (TNG: "Conundrum")
On Federation starships, this type of reactor was often used as a warp core powering the warp drive. The most common version of this system was fueled by slush or liquefied deuterium and its antimatter counterpart, anti-deuterium. These elements were funneled through magnetic constrictors and combined within a dilithium crystal to create a stream of highly energized electro-plasma which was routed to the warp coils within the vessel's nacelles, creating a warp field. (Star Trek: The Next Generation Technical Manual)