Merlin Engine

þ (Thorn): 16,000,000,000W
Efficiency: 1.15þ
Power Type: Nuclear Fusion
Mass: 500,000kg
Length: 100m
Primary Reaction: D+He3 → He4 +3.6MeV +p +14.7MeV (Total 18.3MeV)
Reaction Mass Used: 0.0000188963229593686kg/s
Fuel per day: 1.63kg/day

Although I think a tokamak can be modified to act like an engine, it won't work as described below. The following description is Fi-sics in order to provide a ship engine for the vastness of space. It is a conceit using physical properties of the universe that I've entirely made up. The aim is to minimise fiction to this engine so normal physics can apply to the Robilliverse universe at large. The principles are mostly factual with a twist, minimising the need to suspend belief. All good fiction should follow this rule
Physics In → Fi-sics → Physics Out

The Merlin Engine is a modified Tokamak, using a combination of Superamic and electromagnetic containment. It accelerates its helium fuel product down a skirt and fires it out the back in order to generate forward motion. The engine itself is made up of two parts.

The Tokamak

The Tokamak, in concept is the same as it was when invented. Using magnetic confinement, it keeps the plasma circulating in a spiral that loops back on itself, in the iconic doughnut shape. More advanced magnetic control allows the plasma to work as a centrifuge, spinning the heavier ions to the outer edge of the plasma doughnut. The walls are made of a specialised Superamic that mirrors the magnetic field it is exposed to up to the point determined by mass of Superamic. The next layer contains Seebeck generators that convert heat to electricity. On the outer layer are large magnets that are strong enough to push through the superamic and manipulate the edge of the plasma doughnut. Despite initial theory, everyone was surprised to find that the efficiency of the Seebeck generators increased under such extreme magnetic field manipulation. All the electricity generated from the Seebeck generator is used to manipulate the plasma via the magnet. The engine shell is split into replaceable sections that were given the nickname 'dragon scales'. The Tokamak gets very hot from the irradiation not contained by the magnetic field, mostly light.

The power taken using Seebeck generators to convert the heat from photons hitting the dragon scales is only used to sustain the highly intricate magnetic field. This power is only used by the engine and so is not counted in general use. Power to the ship can be taken from a controlled use of the dragon scale magnets that are used to maintain the plasma field. As the energy in the reaction makes the plasma hotter, and the field strength stronger, this field strength can be extracted via magnets, into electricity. Obviously, the plasma cools as the energy is extracted. The Tokamak can also idle, where it only takes in enough fuel to sustain the plasma where energy is lost to the controlled system.

Superamic Magnetic Feedback (SMF)

SMF opened new methods of propulsion. It was found that an ion, when placed in an open ended narrow Superamic corridor, it will accelerate away from a magnetic fields core, when a field is placed onto it, regardless of charge. It was found that the Superamic interacts with the ion and the magnetic field in such a way as to always push the ion into a less dense magnetic field. As it is an atomic interaction, no control of the magnetic field is needed and the ion will always be fired out.

The Skirt

The skirt is the designed length to extract 15.9MeV from the magnetic field, for each ion fired out, matching the energy generated (18.3MeV minus inefficiencies). The resulting acceleration is 41million m/s/s, where the speed of light is 299,792,458m/s, so the Helium 4 ion leaves the skirt at 1/7 the speed of light.

A change in the Tokamak field directs ions into the skirt, so even if the Tokamak is active, it isn’t necessarily generating acceleration. Also, the subtly in control means the magnetic field switch can rapidly switch on and off, giving in effect a throttle.

The skirt is a ring around the back and the outer edge of the Tokamak, making it look much like a traditional rocket engine, although it works completely differently. Due to the speed and relativistic nature of the ion exhaust, it has been found to react with neutrinos and emit light for 8 meters, slowing them down. From experimentation it has been found that the colour of light always matches the natural emission of the atom the ion would be if it had an election jumping energy levels. No one can explain the mechanism.

Authors Note: I’ve said no one within Robilliverse can explain it as it’s so completely made up I wouldn’t want to try to put an explanation on it.

A Fusion Drill

The same as the skirt but on the front. As the rotation of the ions is circular, the exit is a very narrow inner ring. The high density also protects it from neutrino interaction so the high energy beam reaches out to around 32 meters, where after it still remains a potent beam but not as powerful as in close quarters. Within 32 meters a fusion drill will happily cut through asteroids. Belter’s love fusion drills but the Astry fears them as even a tiny ship can slice anything in half if it gets close enough to it.

Double T’s

þ 32,000,000,000W
Mass: 750,000kg
Length: 120m
Reaction Mass Used: 2x Standard

Developers of the HAAS NorAm Class wanted more power without the bulk of more standard Merlin Engines. They developed the double tokamak where the power is doubled, but the mass is only increased to a total of 750,000kg. More importantly, as the double tokamaks are stacked ‘doughnut on doughnut’, the engine has the same width and only a little more length.

Mini Merlins

þ 1.600,000,000W
Mass: 250,000kg
Length: 75m
Reaction Mass Used: 0.1x Standard

Small ships such as Mining Ships use Mini Merlins which have a tenth of the power and a fifth of the mass.