Talk-Polywell.org

TallDave & djolds1: Thanks for the reference. Looks interesting - it seems NASA doesn't rule anything out until it's been given a good solid try... Food for thought: 20 6 GW BFRs would put out the same amount of power as five F-1s and (if my estimates are reasonable) weigh less than a Saturn V. Not ...

Judging from this you're confusing two concepts: EELVs - which we currently use now VTOL RLV SSTO or TSTO - which is what I've been talking about. I apologize - I started to suspect this partway through my last post, but I kept going because I wanted to very thoroughly dispense with the idea that a...

"Nothing in life is to be feared. It is only to be understood."

- Marie Curie

Kinda ironic...

Surround the reactor with six inches of water (IIRC) and a thin layer of boron-10 and you're good to go. If you use air thrust to get to orbit, there should be no problem with the extra mass. That's just moving the problem around. And arguably making it worse. With that kind of throughput you will ...

Besides, for in-atmosphere application, all you really need to dump heat from is the engine operation itself. Okay, I think I see the misunderstanding. A 6 GW BFR is going to produce well over a gigawatt of waste heat just from alpha bombardment of the grid. If you slow down air at Mach 10 to subso...

Its similar to QED/ARC. Dump the heat into the working remass. How? This is air at hypersonic speed, and you're trying to heat it with a heat exchanger? We have enough trouble doing it with hydrogen combustion, as you pointed out with that 'scamjet' crack... A heat exchanger hot enough to do it wou...

@hanleyp: I'll think it through some time when I'm less busy. It does, however, sound like you're right. The correct 2D case would be a cylinder, not a ring. I was in too much of a hurry...

Without the Faraday shielding effect of some kind of shell (which admittedly is probably necessary in any real system), the hole in the centre is the (flat) bottom of the potential well. It's not a hill. Even with shielding, the torus would have to be fairly skinny for the electrostatic confinement ...

Would it be possible to model the distributions assuming equal charge densities, and then model (and scale) the departure from neutrality as a separate variable?

I guess it would be hard to apply in the areas where the near-neutrality assumption breaks down (like near the electron guns)...

But then he started complaining about ozone production, and that design doesn't really have any way to dump the heat from the reactor (unless you want to go with my big glowing panels idea). Furthermore, that drive only works at hypersonic speed. I'd prefer something that's a bit more versatile. Cur...

The entropy argument isn't valid here because the high-entropy state is not in thermodynamic equilibrium. Take a shock wave in air. The air upstream and downstream is in equilibrium, and the entropy downstream is higher than the entropy upstream. But the shock itself is not in equilibrium, and if yo...

Well, yes it does. The magrid is charged to accelerate electrons into the core. After that is when the magnetic trapping kicks in. It's basically an EXL fusor.

Bad idea. You don't want to "heat" the plasma - it's doing just fine on the drive voltage, and the only thing a bunch of alphas cycling through the core is going to do is scatter ions out of the well before they have a chance to fuse. Also, this would dramatically increase impingement heating on the...

Is it even possible to do direct conversion with a closed box? I doubt it, and if it's not, you're back to a thermal plant and rockets are out the window (except maybe medium-power deep space drives). I can't see the advantage in forcing a closed-box configuration to work (except as a learning exerc...

Hmm... maybe I'm not as clear as I thought on the general configuration requirements for a scramjet. There's a poster on the wall that I walk past every day that shows a scramjet design with a shock spike. It's not difficult to build a rocket into the back of a shock spike. This results in an ejecto...