Talk-Polywell.org

Hey all,

I've been working for about a year and a half on a video game about space settlement. In this game, you can choose various power sources for your space colony, including solar and traditional fission. You can see the fission plant at the bottom of the long axial boom in the image below.



Now I want to add a fusion plant, and obviously I'm imagining this to be a polywell reactor inside.

But what would that look like from the outside? This is in space, so it doesn't need a heavy vacuum chamber. In reality, I don't suppose it would look like much of anything — just another boxy or cylindrical piece of equipment. But that's no fun. How should I model this so that it invokes the idea of a fusion reactor, even if the reality would be far more mundane?

The reactor itself would be more or less spherical, perhaps faceted (the truncated dodecahedron, for example), with protruding knobs, wires, and plumbing. But likely that would be housed for any space applications. Firing this thing up will likely take fairly large electron guns and neutral particle beam injectors.

There will be considerable additional equipment, for power conversion and control.

That big panel might well be in evidence. If the reactor burns DD or DT, there will likely be considerable waste heat and you will need a radiator that would look something like that. Even a p-B11 reactor will make some waste heat. There will be radiators, just smaller.

Radiators could be more decorative. I challenged Vincent di Fate, famous SF artist, as to why his spacecraft all have fins, making them look like dressed-up V2 rockets. He explained that those are the radiators. Even A. C. Clarke's "Discovery" from 2001 (as described in the book) had radiators, and that craft would potentially have had all-regeneratively-cooled propulsion.

Hey Joe,
One of the oft overlooked components to space power systems/system in general are the heat sinks. A decent scale power plant is going to need a large heat sink that would manifest externally. And, by the way, be at risk to micro-impacts...

Also, a Polywell in space is still going to need a vacuum chamber similar to earth, given that it is a gas generator and that will need to be managed during operations by a vacuum system. The engineering requirements may not be as demanding, but none-the-less the requirement will remain.
I don't think you are going to have a 'glowy ball' at the end of a stick. I believe it is going to much more mundane.

I would begin by listing key main components, and then generating a form factor for each. Then take those form factors and glue them around the end of a stick away from the people tank. Or, if integral or alongside the people tank, you will need to address a shielding system form factor as well.

Rough draft at a Polywell component list:
Reactor chamber - polyhedron of your choice
Vacuum system - pumps and pipes with collection or venting system
Power collection system - venetian blind cylinders?
Neutral Beam Injectors - cylindrical chamber bolt ons.
Electron Beam Gun(s) - cylindrical chamber bolt ons.
Start up system - small box or cylinder bolt on.
Fuel supply - Tanks
Heat Sink - large heat exchanger panel/radiator system attached to reaction chamber/power collection system
Startup power system - large capacitor/battery bank?
Power Conversion System - depends on collection system. (could be a fluid thermodynamic cycle, could be direct conversion...)

My $0.10 worth!

Dang it Tom! You hit submit before me! So close!!!

Thanks, guys! Radiators are a separate component; in fact that's what that giant fin is in the image above. (It has sunlight on it only in design mode; when you actually build your colony, the radiator always faces directly towards or away from the sun, to see as much black sky as possible.)

So, yeah, radiators, check.

Good ideas with the other components... I think I'll go for something spherical (or dodecahedral) with lots of cylindrical bumps sticking out for electron guns. Yeah, in reality these would all no doubt be hidden away inside the shell... but that's dull!

I wondered if that was a radiator or solar array. In the end, I went with solar array in my mind.
Solar arrays are probably going to remain a key component of any inner/mid solar flight system regardless of main power.
It is too easy a backup/supplement to overlook.

You may not need a vacuum chamber for a fusion reactor in space, but you'd still want some radiation shielding, maybe a shell to collect fuel that leaks out of containment, and something to keep out stray debris. A loose steel nut floating into the reactor magnets could force a shutdown until it could be removed and the impact damage repaired.

Firefly

JoeStrout wrote:
Good ideas with the other components... I think I'll go for something spherical (or dodecahedral) with lots of cylindrical bumps sticking out for electron guns. Yeah, in reality these would all no doubt be hidden away inside the shell... but that's dull!

Aw, just show it with the hood open. You've seen the car nuts showing off their engines ... chromed valve covers, high pressure hoses. The stainless steel hardware should shine up nice!

Yes, while you could technically run one bare and get the fusion reaction, you need considerable structure to support the magnets (WB8 supports them from the outer wall). Without walls or some sort of energy collecting structure, the fusion products will go flying off into space (this applies to thermal or direct conversion).

Maybe it would look just like a regular shipping container, with living quarters for one Italian operator inside.

Well, maybe not.

For military ships you may want to use moving/rotating directed radiators, to hide thermal emission (from one side at least). Otherwise they will be too easy to detect and target weapons/missiles on it.

Hmm I read something about relativistic effect of space war. basically at a certain point your shooting at where they were not where they are.

paperburn1 wrote:Hmm I read something about relativistic effect of space war. basically at a certain point your shooting at where they were not where they are.

Depends on speed. Anyway, even if you move close to speed of light (and harder to hit with a weapon) - you don't want to be detected. There is not many thermal sources in the space, so any ship will be very easy to detect because its thermal emission. That is why you want to direct your coolers emission to radiate away from infrared detectors of your potential enemy.

vasimv wrote:

paperburn1 wrote:Hmm I read something about relativistic effect of space war. basically at a certain point your shooting at where they were not where they are.

Depends on speed. Anyway, even if you move close to speed of light (and harder to hit with a weapon) - you don't want to be detected. There is not many thermal sources in the space, so any ship will be very easy to detect because its thermal emission. That is why you want to direct your coolers emission to radiate away from infrared detectors of your potential enemy.

Its actually a combination of velocity and distance. And you always want to lead your shots -- shoot where you expect them to be when the shot gets there. Shooting at their current position doesn't even work well at terrestrial distances.