Talk-Polywell.org

These wires are not for the magnet coils. Their magnets are monolithic aluminum.

Yes, of course. The wire must be intended to connect the coils to the capacitor banks. Here is a picture:
https://spectrum.ieee.org/fusion?utm_ca ... atetechsub

The high voltage explains the structural glass insulator construction of the machine we see in photo. It is really a marvel of technology. The timing to make this machine work is incredible, no wonder it is only now that technology would enable it to be built.

Skipjack wrote: ↑

Sat Nov 04, 2023 12:19 am

These wires are not for the magnet coils. Their magnets are monolithic aluminum.

Thanks

I wouldn't want to be an electrician on that installation crew. Talk about mind numbing repetition. That's a lot of wires and caps.

ladajo wrote: ↑

Tue Nov 07, 2023 5:44 pm

I wouldn't want to be an electrician on that installation crew. Talk about mind numbing repetition. That's a lot of wires and caps.

From what I understand, they have established a good and efficient process for all of this. Might not be as bad as it seems...

Wire length between capacitors and aluminum rings has to be measured along with controlling pathway to avoid inductance differences even though it is DC (it is timed, pulsed DC).

Helion capacitor manufacturing:
https://x.com/Helion_Energy/status/1722 ... 20932?s=20

We continue to scale up capacitor manufacturing in Antares. Our team is now producing 20 new capacitors a week, which will make up 10% of Polaris’ capacitor bank.

So Polaris will need 200 capacitors, or 10 weeks worth of manufacturing. They probably have produced a significant amount already, since they did not just start doing that a week ago...
So if that was the limiting factor, they could produce a new power plant every 10 weeks at the current pace. Still a while to go until they have production up to the pace they eventually want to reach. But great progress nonetheless.

Skipjack wrote: ↑

Thu Nov 09, 2023 11:23 am

Helion capacitor manufacturing:
https://x.com/Helion_Energy/status/1722 ... 20932?s=20

We continue to scale up capacitor manufacturing in Antares. Our team is now producing 20 new capacitors a week, which will make up 10% of Polaris’ capacitor bank.

So Polaris will need 200 capacitors, or 10 weeks worth of manufacturing. They probably have produced a significant amount already, since they did not just start doing that a week ago...
So if that was the limiting factor, they could produce a new power plant every 10 weeks at the current pace. Still a while to go until they have production up to the pace they eventually want to reach. But great progress nonetheless.

Yep, capacitor production volume is going to be critical.

Magnetic field energy density scales with B^2, and Helion's power plant reactors will require even higher magnetic fields.

Polaris' power bank stores 50 MJ, for a peak B field of 15 T. A power production machine reaching 30 T will need 4 times that (assuming same final plasma volume).

To keep with their commercialization plans, they'll need to increase production capacity by orders of magnitud.

I have never heard about it being 30 Tesla. Last number I got was 20 Tesla used for the graphs in their recent paper.

Skipjack wrote: ↑

Fri Nov 10, 2023 9:22 pm

I have never heard about it being 30 Tesla. Last number I got was 20 Tesla used for the graphs in their recent paper.

For the 50 MWe machines it'll have to be higher than Polaris 15 T, but we don't really know the number. On past papers and presentations they've mentioned different figures.

For example, this one from 2016 speaks of 40 Tesla (page 2).

charliem wrote: ↑

Sat Nov 11, 2023 5:47 am

For example, this one from 2016 speaks of 40 Tesla (page 2).

That one was for low pulse rate, high gain D-T, not the high pulse rate low gain they are going for. I know for certain that the graphs in their recent papers were for 20 Tesla magnets. They might go up a tiny bit with field strength and/or size of the power plants but I have not heard anything about 30 Tesla magnets for the power plants.

the final magnet size would depend on a number of factors, they probably want to keep that as small as possible given how it drives final cost

Trenta was 8T, and Polaris is 15T, so 30T is probably a reasonable guess for the first demonstrator plant

ideally we'd see a commercial reactor eventually work its way back down below ~20T with better compression timing, harder to compete with LWRs at 40T+

ether way it is very exciting to hear they expect net electricity gain in 2024, even if it's probably only 1.1MW from a 1MW pulse

that is still many decades ahead of any such planned output from the ITER or NIF paths

Again, I know that the graphs in their papers are for 20 Tesla. I believe that 30 Tesla would be hard to achieve. We will see how things go.

fwiw Skipjack, agree it will be technically difficult to achieve 30T, suspect they are hoping Polaris results keep them under 20T for the next model

20T still seems to be practical maximum for SC magnets, but even at that size you'd have to worry about flux creep

larger than that and you're trying to break new ground in SC magnets -- a big ask!

of course 45T was achieved in 2014 (at 30MW), but presumably Helion can't use a Bitter magnet given the resistance losses and heat dissipation requirements

otoh if Polaris achieves even a single net-power pulse at 15T you'd have to think the money is going to fall like rain

hmm otoh their machine is pulsed and I see LANL has achieved 100T(!) in a pulsed magnet, though apparently not SC and I'm not sure for how long

so now I'm not really sure how hard 30T would be for FRC reactors

Helion's probably thought about this a lot more than I have though, maybe they'll share some next-gen designs this year

their plasma electric recapture idea is very elegant, similar to a Nebel design I saw floating around a few yeas ago

Helion themselves say a 10 T FRC outperforms a 44 Tesla Tokamak

https://www.helionenergy.com/faq/

"Fusion reaction rates (the amount of energy produced) scale as magnetic field to the 4th power, an extremely strong scaling. However, that is the magnetic field inside the plasma, not outside. A 10 Tesla Helion FRC outperforms a 44 Tesla Tokamak."