While i am eager for Polywell to scale up and reach / surpass the energy break-even point, so does the cost increase for hardware materials.
Someone on this board mentioned that for polywell to become succesfull we should not only look at getting a bigger power output, but also lower the power input/ material costs
How about considering an extremely scaled down version in the nanoscale regime, using Mems and/or Lithography fabrication methods from the chip industrie?
Let's for a moment entertain that it is even possible,
The energy output of a single nano/micro sized polywell would be far from impressive, but perhaps mass fabricated wafers of them would make up for that in terms of material and production costs.
Once you covered the initial research costs, you could churn them out by the millions, lowering the cost of a single unit, lets also consider the supportive hardware costs for larger polywell, like huge expensive vacume chambers, magnets, cooling requirements etc.
Oppertunities in the nanoscale regime:
- Do away with large vacume chambers, the wafer, consisting of multiple polywells is covered by a plate and has a small micromachined pump.
- on die polywells are controlled by chips baked on the same wafer.
= you could plug multiple wafer units into a rack powerserver to meet increased energy demands.
- very small confinement space, thus:
* small magnets, low field requirements, magnetism effect dimishes with distance, so bigger polywells must have increasingly bigger/or more powerfull magnets to cover the distance to the center, it doesn't scale linear, precisely why magnets in close proximity can take advantage of their near-field strength.
* small magnets, low field = low power input, low cooling requirements, possibly even passive cooling and/or on chip peltier cooling stuff.
- mems/nano sized polywells could be at least a starting research point for universities that cannot cough up the initial costs for a large vacume chamber etc, this would widen the collective effort in the whole polywell research area.
- More affordable Prototyping and testing in mems/nano, validation of concept before building full scale macro sized powerplant etc.
- very small confinement space, perhaps a relatively denser/larger crossection for ions to hit and very short return paths for electron escaping from the cusps, shortened electron return time possibly increasing electron density in the center.
These are just wild guesses, I would need the opinion of someone with more technological background for this...
What do you think?
1st post: nano/mems polywell?
I rather suspect the issue is that you need big pd's to accelerate particles to 'fusible' energies, and there are basic arcing constraints according to the purity of the background.
That being said, a much smaller non-fusing device might be possible, as proof of principle, but it looks like folks already want to, and have the funding to, build what the theory says should be a fusing device. Such an outcome will therefore clearly carry more significance in evidencing viability.
That being said, a much smaller non-fusing device might be possible, as proof of principle, but it looks like folks already want to, and have the funding to, build what the theory says should be a fusing device. Such an outcome will therefore clearly carry more significance in evidencing viability.
The Polywell is dependant on equal opposing magnetic fields that have a torus (round to almost square donut shape ). To achieve this with planetary bodies would require moving a lot of them around and spinning them up to achieve anything approaching magnetic field strengths required. Then there would be the problem of trying to keep the bodies in some kind of stable orbits.To do that you would be well beyond Star Treck Technology, and the controlled energy to set up the geometry (if possible at all) would require energy input that would otherwise provide all of Earth's energy needs for at least a few trillion years.physx wrote:How about a gigascale polywell using space/or the moon as its vacume chamber and a few minimagnetospheres to replace the solid magnets and create a virtual wiffleball several tens/hundreds metres diametre, the positive charged ions could be harvested from the solar wind
The magnetic field interactions between Jupiter and some of its moons might have some interesting local magnetic field structures, but I dought if they could confine anything to the degree needed, certainly not in a Polywell scheeme.
The solar wind is primarily protons (hydrogen ions) and helium ions. Deuterium or any other ion would be extreamly rare.
Certainly a Polywell reactor in space would have no vacuum maintainance concerns, much less concerns about neutral atoms/ molecules building up, and potentially less radiation concerns. But, the cost of getting into space has a different set of problems. If the power generated then needs to be transmitted to Earth's surface there is yet another set of expensive and difficult challenges to overcome.
Dan Tibbets
To error is human... and I'm very human.
Good point...unless the escaping fuel ions are also focused for direct thrust. Not nearly as energetic as fusion ions, but still perhaps several thousand eV or more. That is a lot hotter than chemical reaction products, and may be close to the average energy of a dilluted fusion product engine. The efficiency of the engine might be mildly to moderatly less, but this would be countered in part by the presumably lighter reactor. The increased reactor fuel storage would be counterbalanced by smaller inert dillutional fuel storage (?). Deuterium and especially helium 3 may be to expensive for this, but p-B11 fuels woul be cheap at least if you refuel from solid bodies (ie - mining dirt- hydrogen or deuterium could be harvested from the atmospheres or ices of a number of planets, moons, or comets, but boron would have to be dug up. Admittedly, boron 11 is not as cheap as simple hydrogen as the dillutional fuel- but, the nessisary excess boron could be carried in much smaller tanks to offest some of the decreased efficiency of boron compared to hydrogen in terms of ISP. Carrying the isotope processing equipment on the ship instead of on a convient station would tilt the equation more twoards conserving as much fusion fuel as you can.MSimon wrote:My estimate is that the fuel flow in a Polywell will be many times the burn rate. You may still need to carry pumps with you if recirculating fuel is a good idea.
Dan Tibbets
To error is human... and I'm very human.