ELECTRO PLASMA SYSTEM (EPS)
The Warp core is the part of the warp drive in which power is generated through a controlled annihilation of matter and antimatter, also referred to as matter/anti-matter reaction chamber (M/ARC). The complete warp power generation system including the warp core, matter and anti-matter injectors and constriction elements, is called the matter/anti-matter reaction assembly (M/ARA).
Matter and anti-matter streams are combined in the Dilithium Crystal inside the warp core, resulting in a plasma stream. A failure of anti-matter containment is commonly referred to as warp core breach. In this case anti-matter can get in contact with matter, leading to a disastrous explosion that in almost every case destroys the ship. In case of containment failure the warp core can be brought to an emergency shutdown. If the shutdown does not work, it is possible to eject the whole M/ARA. The problem of containment seems to be especially severe in Galaxy Class ships, three of which have already been destroyed by warp core breaches, though they were supposed to have a lifetime of 100 years.
At either end of the Warp Core assembly are injectors. One for Matter and the other for Anti-matter. The Injectors use a combination of force fields of various types and mechanical pumps to inject the Matter and anti-matter into the warp core creating a stream. The stream is contained, guided, and accelerated as it proceeds down the Warp Core shaft by further Force Fields until it finally reaches the Dilithium Crystal matrix where the actual reaction occurs.
The Dilithium Crystal is an essential component of the warp drive. The crystal is used to focus and redirect the matter and anti-matter streams so that they collide and are converted to an electro plasma stream in a controlled mutual annihilation. Once the Electro Plasma is generated it is directed into the EPS conduit system. Dilithium is the only known element to be non-reactive to antimatter, however this resistance only occurs when the Crystals are subjected to a high frequency electromagnetic field in the megawatt range. The efficiency of the reaction inside the Crystal depends on its quality. While naturally occurring crystals had to be used in the 23rd century, mono-crystalline Dilithium can now be produced by means of epitaxy.
Starships are also equipped with Fusion Reactors. Fusion Reactors generate energy as a byproduct of a fusion reaction, usually employing hydrogen/deuterium that is fused to helium. The fusion reactor is used to power the impulse drive on most Federation Starships. The energized plasma generated inside the reactor is then accelerated, fed into a driver coil assembly and eventually exhausted, yielding the desired propulsive effect. The impulse reactor is also used as an auxiliary power source for other ship systems.