Fusion

Fusion power is one of the four primary sources of energy generation for modern civilization, the others being solar power, antimatter, and klein taps. Fusion is generally used on more portable devices, called Portable fusion generators and used by the general populace (PFGs for short). Advanced strains of the cerevate races actually perform this function biologically or otherwise internally, allowing them to operate for extended periods without any form of sustenance.

There are four main types of fusion generators.

Megafusor

Essentially, a fusion reactor that is, on its own, a megastructure. The only such device built by humanity was a thousand kilometer-wide globe at the center of Ouranos Prime, and was, quite literally, a miniature star. Unlike a normal reactor, a megafusor is fully capable of fusing hydrogen and helium, and could potentially have a power output rivaling a red dwarf.

Active megafusors are rare, though several relics of others exist. Ouranos Prime suffered heavy damage during the Purge, and its status is doubtful. The need for such a superstation is not often replicated - when such disputes arise, most just move to a different star and use its light. Their use is generally to breed lighter (lithium to manganese) elements instead.

Reactor

The main difference between a reactor and a PFG is one of scale. Although they use a variety of different approaches to fusion, anything smaller than a megafusor primarily fuses deuterium, tritium, helium-3, and lithium. A reactor typically refers to a permanent installation on a station or planetary body, and most of the lithium in the solar system is destined for these reactors.

Because these generators are much more massive, they can operate at extreme temperatures, and are capable of boron-hydrogen fusion, unlike the smaller, more portable generators described below. This allows them to avoid the issue of neutron embrittlement entirely, instead of relying on exotic shielding.

Propulsor

A propulsor generator is essentially a plasma engine that takes advantage of fusion. When in use, they do not produce much energy directly, but instead helium is funneled out of them at extreme speeds, along with focussed light, driving the craft. They usually use pure deuterium as fuel. With exomatter, these drives are extremely efficient, and inexpensive. Class B patterns are sometimes used, but infusions and hypomatter are far to rare and valuable to be wasted on such common technology. Instead, if these items are used in a propulsor-type drive, antimatter is used as fuel, or the ship is driven directly by a klein tap.

When nearing 100% efficiency, such drives generate about 32,249 Newton∙seconds of thrust per gram of fuel, having an exhaust velocity of roughly 10.75% of c. Unless using exomatter and/or patterns, the most powerful such propulsor engines can barely fuse gram quantities while maintaining such efficiency, which is absolutely required without being forced to convert most of the ship's mass to a giant heat sink. While this makes them horrendously slow, they make up a solid staple of civilian shipping fleets.

Exomatter eases these restrictions somewhat, to the point of allowing for moderately useful combat operations in space. Such ships are usually still civilian in nature, as facing something like a regalic ship in such a vessel, or a fleet of them, is tantamount to suicide. In order to pose a meaningful threat, one usually uses antimatter solutions.

Generator

Due to the connotations involved in calling a package worn on the hip a reactor, the lightweight equipment used to power vehicles and common appliances are referred to as generators. Like propulsors, they are usually fueled strictly with deuterium, to conserve mass. A generator typically produces about 300 terajoules per kilogram of fuel. They usually are quite simple, fusing picogram quantities, and few supply more than a kilowatt.