Miramor wrote:Umm what? You can't just use any set of superconducting coils, you need them arranged into a tokamak or a stellerator or something.
tokamak, etc are just the shape the coils are set up as, which just determines the flow and handling of the plasma.
But we were already talking about an engine which by default would have a design arrangement to channel the plasma. So yes, you just need super conducting coils. Everything else is just design and efficiency.
In fact tokamak is something you would primarily use to contain the plasma instead of using it for thrust. Which is why they are using that design in fusion reactor research, which if you used in a ship engine design is more in line with Star Trek Impulse Drives since they also are used to help generate ship power.
You really just need a solenoid or magnetic mirrors to just shoot the plasma out and prevent radial emission of plasma.
chuck_starchaser wrote:What about radiated heat. With plasma at several million degrees, you can "feel the the heat" from far away...
Not that I disagree, in general; what you're saying is precisely what makes a VASIMR thruster efficient, but you still need radiators and cooling.
Which is why I mentioned vacuum, which prevents convection of heat.
The only heat left then is from the direct light and infrared radiation, a tiny fraction of the total energy generated in a fusion reaction, but that can be refracted/reflected and thus all the heat can go out with the plasma.
It's the same way they plan to make fusion reactors, the plasma will run in the million degrees, which no substance on earth can withstand but it'll all be kept contained with the magnetic field that keeps the plasma from ever coming into contact with the walls of the reactor.
The magnetic confinement can also be propagated throughout the plasma since plasma can also conduct the magentic field. So depending on the field arrangement the plasma can be pretty well focused and most of the heat would be contained with the plasma itself, since just like a combustion engine you need some energy to go back in to keep the process going.
They can thus control the interaction. If they didn't then the fusion reaction could easily sputter out since you need a critical temperature to keep the process going and if too much heat and/or plasma escapes confinement then the walls of the chamber get melted and mixed in with the plasma and effectively cool it and reduce it's efficiency.
Alternatively they can use either part of the plasma flow and/or the radiated energy to help power the ship, which really wouldn't require heat venting then since the energy would be getting converted into electricity to help power the ship.
But of course that depends on how efficient the method used for converting that energy is.
Modern methods are very inefficient but one would think by the 27th century that they would have developed better ways of converting one form energy into another.
Though using the engine for power would fit with the apparent link between boosters and energy weapon power usage in the game.
Additionally, just like traditional rockets the engines could be lined with special materials to deflect the heat so it gets channeled along with the exhaust. Making the engine exhaust nozzles the main heat radiator.
Course we are assuming the engines are using nuclear fusion to generate the plasma.
Plasma can actually be relatively cool depending on what you are turning into plasma. Like everything else different materials will turn into plasma at different temperatures. So there is such a thing as cold plasma.
But hot plasma is more effective as a propulsion energy source.
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