Talk-Polywell.org

So if this pans out, what will be the mid-term and long-term development plan?
I thought Bussard said there was no reason to go right to pB11 fusion. Is that true? Or, is there some reason to go to D-D fusion first? What about another pre-net fusion device before anything else?

Probably the first 2 major issues:

We need proof of scaling.
WB-7 has roughly 35cm coils, make a truncated cube WB-8 with 70cm coils. IIRC scaling says double the size and get 128x the output.

We need a carburetor.
MSimons LN2 cooled WB-7x might be perfect for this. A 10+ minute run is proof of the carburetor. Shape of the well may come into play here (Chacons parabolic well). Tuning the carburetor probably requires many runs under different configurations, and WB-7x is great for this.

Bussards 3 meter 500MW net power proof of concept wasnt for PB-11 ?

Thanks Roger.

I made a typo in my original question, I should have said/asked:

"I thought Bussard said there was no reason NOT to go right to pB11 fusion."

Assuming Nebel and crew get favorable results, it sounds like there are at least two reasons to hold off a bit longer on building the net power device.

rj40 wrote: Assuming Nebel and crew get favorable results, it sounds like there are at least two reasons to hold off a bit longer on building the net power device.

Didnt Bussard want to build the trunc dodec ?

I'm curious about well shape/optimizing. Riders square well tends to have hi brem losses, a parabolic or spiked well has other characteristics.

On the other hand a 1.8 meter DD fueled 100mw net power design, in pulse mode, as in WB-6&7, would not be too expensive. And would blow the crap out the entire scientific community if successful.

So does Dr Nebel think he can hit a home run with the 100mw device ? Apparently yes.

On the other hand MSimons LN2 cooled "Convincer" should be capable of being a test bed for carburetor design, and PB-11 fusion. Proof of PB-11 fusion would also blow the crap out the entire scientific community.

Polywell net power in the 1.8 meter area vs ITER..... LOL, OMG.

So maybe "we" should be building more than one device after WB-7.

Roger wrote: On the other hand a 1.8 meter DD fueled 100mw net power design, in pulse mode, as in WB-6&7, would not be too expensive. And would blow the crap out the entire scientific community if successful.

A pulsed 1.8 meter WB machine sounds interesting from a financial point of view. Big enough to prove net energy production both with D-D and with H-11B. No need for SC coils (no more that WB7) nor colleting grids for alphas or materials that can withstand the rough conditions for long, no cooling (100MW, steel vacuum chamber 3 meters wide 2 mm walls => weight 0.84 metric tons => heating aprox 275 K/s), cheaper power sources and vacuum systems. How much would that reduce costs?

Frankly, I doubt that many companies (or gubernamental departaments/organizations) will jump into advancing 200 M$ after WB-7, even if results fulfil every and each of Bussard's claims, but 20-40M$ would look much less frightening, even if it'd turn out to be a waste of time and money in the long run.

charliem wrote: Big enough to prove net energy production both with D-D and with H-11B.

IIRC, no.

DD, breakeven at 1.5 meters, 2 meters for 500mw net power.
PB-11, breakeven at 2 meters, 3 meters for 500Mw.

Roger wrote:

charliem wrote: Big enough to prove net energy production both with D-D and with H-11B.

IIRC, no.

DD, breakeven at 1.5 meters, 2 meters for 500mw net power.
PB-11, breakeven at 2 meters, 3 meters for 500Mw.

Well, then 2 meters instead of 1.8 (only 37% bigger in volume/cost) and capable of doing both.

Although there is something I dont catch. From the figures we have about WB6 neutron production it only gave about 1 miliW or less, if the scaling law where just R^7 that'd mean that a 2 meter machine would generate 585000 times the output of a 30 cm one (WB6), roughly 600 watts.

So, where is the trick? Are they going to ramp up the magnetic field way beyond the physical size? Something else?

BTW, if the main scaling law is B^4*R^3, couldn't conceivably be made net producing WB machines at smaller sizes than those, by increasing B.

charliem wrote:

Roger wrote:

charliem wrote: Big enough to prove net energy production both with D-D and with H-11B.

IIRC, no.

DD, breakeven at 1.5 meters, 2 meters for 500mw net power.
PB-11, breakeven at 2 meters, 3 meters for 500Mw.

Well, then 2 meters instead of 1.8 (only 37% bigger in volume/cost) and capable of doing both.

Although there is something I dont catch. From the figures we have about WB6 neutron production it only gave about 1 miliW or less, if the scaling law where just R^7 that'd mean that a 2 meter machine would generate 585000 times the output of a 30 cm one (WB6), roughly 600 watts.

So, where is the trick? Are they going to ramp up the magnetic field way beyond the physical size? Something else?

BTW, if the main scaling law is B^4*R^3, couldn't conceivably be made net producing WB machines at smaller sizes than those, by increasing B.

I think WB6 was run at well depths significantly below what's possible.