Fusion Power in Infinite Fleet

The USF primarily uses fusion power for most of its energy needs, supplemented by antimatter power to supply the very intense bursts of energy needed to achieve warp. The reason we went with fusion instead of creating some kind of ethereal alien energy or using some kind of vague sci-fi power source like dilithium crystals is simply that fusion has the potential to create the level of energy output we need, and we don’t actually need to make things up.

The primary limiting factors currently for fusion power are all material science problems; the physics is quite well understood. There are really two paths to fusion being explored deeply right now: either Hydrogen-2 fusing with Hydrogen-3 (Deuterium-Tritium reaction), or Helium-3 fusing with either Helium-3 or Tritium.  

Deuterium-Tritium fusion works at the lowest plasma temperatures and produces plenty of energy output, and there is enough deuterium and tritium in sea water to power all human consumption for the next billion years or so. However, there is a disadvantage: the reaction emits much of its energy as neutrons, which are not contained by magnetic fields, so they escape and hit the walls inside the reactor, making them radioactive, transferring heat, and causing wear and tear over time.

So, to make Deuterium-Tritium fusion practical, we primarily need a better material for neutron shielding, one that wears out more slowly, and harvests heat more efficiently. The heat is then used to vaporize steam and power a turbine to get electricity. We also need to make the reactors big enough to minimize energy loss from bremsstrahlung and cyclotron radiation (there are a couple ways around this, but bigger tokamaks are the simplest solution).

The other path, Helium-3 fusion, takes a different approach. It takes much higher plasma temperatures to start it up, but the fusion products are mostly charged particles, which can be harvested to electricity directly instead of using a turbine; this increases energy efficiency about 3x compared to best estimates for Deuterium-Tritium.

Helium-3 to Helium-3 fusion also doesn’t produce any neutrons, so there is much less wear and tear on the reactor innards. However, we don’t yet have magnetic containment strong enough to generate the plasma temperatures needed to do this fusion. So, to make Helium-3 fusion practical, we need a better material for high-temperature superconducting magnets, one with a higher maximum field strength.  Helium-3 is also very rare on Earth, so we would probably need to colonize the Moon and mine it there (the Moon has plenty, scientists believe).

Both problems are material science problems, and real-life scientists are making active progress on them now. Once either problem is solved, humanity will enter a new era of energy production. In the world of the USF, though, both problems have been solved, which allows us to use the simplest energy source of all: Hydrogen-1, or proton-proton fusion. This reaction is much harder to achieve even than Helium-3 fusion, requiring plasma temperatures hundreds of times higher to make it efficient.

However, there is literally no fuel more common in the galaxy, and one of the output products is positrons; an antimatter component. USF technology harvests these positrons and stores them, slowly charging our antimatter containment devices (excellium crystals) with power that can be expended in a burst for warp maneuvers.  

With proton-proton fusion as a power source, reactor fuel is so common that USF ships will essentially never run out. You can get it at any gas giant in the galaxy, with nothing more complicated than an air scoop, and a supply of a few tons will last for several years of continuous flight - weapons and shielding, however, do consume massive amounts of energy.

The same magnetic containment technology is also the key to our plasma weapon designs and our high-powered RIoT (Relativistic Ion Thrust) drives, where pumping a few grams of xenon per second through a particle accelerator can push ships bigger than aircraft carriers at accelerations higher than the maximum g-force tolerance of an unaugmented human (fortunately, USF personnel are nanite augmented to resist such accelerations).

No current accelerator can handle “grams per second” throughput, but no current accelerator has a fusion reactor as a power source, or USF level magnetic containment. Better superconductors would open both those doors, and allow the engineering of truly massive interplanetary spacecraft, where weight ceases to be a driving design consideration. At that point you can realistically have the armor and guns that make space war games fun.

So, for Infinite Fleet, we are trying to limit the amount of fantasy needed to create our world, and keep it as realistic as possible. There are some exceptions, of course; in real life nobody has figured out how to warp, and antimatter containment in excellium crystals is mostly fantasy. But dig deep into our lore, and you might be surprised how much actual science you find.  

And, if you want to make our universe real, then become a materials scientist focused on superconductors.  

All Posts

2021 (20)