Talk-Polywell.org

So..... This means a smaller polywell?

A practical, high temperature, high magnetic field tolerant superconductor would generally mean smaller and/or more powerful Polywells, yes.

This is not even close to practical yet, given the low process yield and other factors, but you have to start somewhere, and Joe Eck seems to be one of the trailblazers.

I, however, have more hope for Johan Prins' diamond approach in a fusion environment, given the robustness and high thermal conductivity of diamond film.

The more competing HTS concepts that are presented to the public, the better, in my view.

No, just one with fewer support systems like cryo-coolers... IF three things are shown true. First, this material is actually susceptible to being turned into viable cable. Second, said cable can withstand B field strengths similar to currently anticipated designs. Third, the cable can withstand neutron bombardment fluxes similar to currently anticipated designs. All three BIG ifs.

KitemanSA wrote:No, just one with fewer support systems like cryo-coolers... IF three things are shown true. First, this material is actually susceptible to being turned into viable cable. Second, said cable can withstand B field strengths similar to currently anticipated designs. Third, the cable can withstand neutron bombardment fluxes similar to currently anticipated designs. All three BIG ifs.

That's essentially what I said ("practical", "high magnetic", "robustness").

But, you ignore the smaller magrid minor diameter due to a lessened cooling and insulation requirement.

Dminor for LHe > Dminor for LN2 > ... > Dminor for H2O > ... (> Dminor for Air?), as usable Tc goes up.

DeltaV,
Actually, I didn't ignore anything you wrote, I just didn't see them. Note that I posted just after you did. I was responding to bennmann.

All is forgiven. I have recalled the drones.

I'm stealing that delta, I don't care if I have to wait 20 years to use it again in a similar situation.

And now with my drone army waiting for the right moment to strike, your drones will have a hard time stopping me.

bennmann wrote:I'm stealing that delta, I don't care if I have to wait 20 years to use it again in a similar situation.

And now with my drone army waiting for the right moment to strike, your drones will have a hard time stopping me.

I have an army of queens.

Do they lithp? Ask them.

Improved superconductors with mush less cyro cooling requirements could result in smaller machines, and as fusion output generally scales at the 4th power of the magnetic field strength, theoretically Gigawatt generating machines could be smaller than a bread box.

But, this ignores heat loads. Even with P-B11 fusion without neutrons, and direct conversion,there is still a lot of x-ray heating, and also heating from the 10-20% of the fusion power that is not converted directly. The often quoted heating tolerance of up to 1-2 MW per Meter square, will possibly be the limiting size constraint, even if the B fields and obtainable voltages could provide denser energy levels. Then there are the engineering considerations for wall cooling, direct conversion apparatus, etc.

A lab model that operates for very short time periods might be remarkably energy dense, but a practical power plant is another matter. With Bussards engineering background, I suspect a ~ 3 meter D-D Polywell magrid makes engineering sense and physics reasonableness both. The vacuum vessel may be 2 or even 3 times that diameter. A P-B11 Polywell might actually be smaller than a D-D Polywell if the B strength is maximized, because the wall heat loading concerns may be smaller and this may end up being the size limiting factor.

Dan Tibbets

Again, the transition temperature of the SC is not a direct factor in the equation but only in how it may effect the current vs B Field function. An SC with a 400K transition temperature may have a VERY low current capacity under a magnetic field. You might wind up with an SC magnet that can only generate 0.1T at 400K. Not very helpful, for a Polywell.