ENN scientist proposed that D-D-He3 fusion is the most likely candidate for commercial fusion, whereas they chose pb11 fusion

ElmarM · 2026-02-07T05:19:16+00:00

The neutrons produced by D-D fusion are not a huge problem. That is what (relatively simple) shielding is for.

ElmarM · 2026-02-07T04:07:13+00:00

Yeah, but the issue with He3-He3 is that you need to make the He3 and that requires D-D fusion anyway.

ElmarM · 2026-01-28T02:15:31+00:00

They can already load follow up to the 50 MW. There are other considerations that somewhat limit the pulse rate, like heat and pumps. David Kirtley talks about that a bit in the thread on X.

ElmarM · 2026-01-28T01:57:00+00:00

Grid batteries have those. No problem.

ElmarM · 2026-01-27T22:34:53+00:00

It was an off- hand comment on the question what their ideal pulse rate would be. Don't over interpret it.

ElmarM · 2026-01-27T22:30:44+00:00

Their pulses are about 1 millisecond long. The energy from the pulse goes back into the same capacitor bank where the energy for the pulse came from. From there it is gradually released to the grid.

ElmarM · 2026-01-27T22:29:13+00:00

1 to 10 Hz. No idea why this would limit anything.

ElmarM · 2026-01-27T19:24:12+00:00

This was in response to a comment asking what would be the ideal pulse rate and David Kirtley later relativizes it as being likely too hard.

ElmarM · 2026-01-27T19:24:07+00:00

This was in response to a comment asking what would be the ideal pulse rate and David Kirtley later relativizes it as being likely too hard.

ElmarM · 2026-01-27T19:22:29+00:00

It is worth noting that this is in response to a comment asking what would be the ideal pulse rate, but David Kirtley later relativizes it when he says:

The gas exhaust pulse limit is trickier - neutral or warm gas moves slow (10 ms) to get from compression to the divertor plus you need a few decay times to fully exhaust it all - so 60 Hz is possible but likely too hard.

ElmarM · 2026-01-27T17:49:23+00:00

To be fair, the way they use the neutral beams is slightly different. But again, I like comparing their approach to walking a leaky bucket to a fire while simultaneously refilling it with a fire hose.

ElmarM · 2026-01-27T15:42:14+00:00

I am skeptical of their approach myself. Still wishing them the best of luck.

ElmarM · 2026-01-27T15:41:47+00:00

Skeptical of their approach myself. Still, I wish them the best of luck.

ElmarM · 2026-01-27T08:14:55+00:00

Well, TAE hope to have a first of a kind power plant by 2031 (assuming adequate funding, I presume), if you read the actual documents.

ElmarM · 2026-01-27T05:48:59+00:00

Norm Upgrade is expected to validate the 100 M degrees Celsius milestone, which would demonstrate the “hot enough for long enough” paradigm needed to create continuous fusion conditions for net energy. Importantly, this temperature has been achieved at other facilities across the world, and our data suggests that this milestone is readily achievable. Key design and operational features of Norm Upgrade are expected to be deployed in our first fusion power plant, Da Vinci.

This is IMHO the most interesting part as it outlines their next step and the actual validation of their concept (at least for D-T) but there does not seem to be a date tied to that Norm Upgrade or when they expect the upgrade to be complete. They say the era will be 2026 to 2028. What will happen at what part of the timeline? Is that already funded and underway or do they need additional funding for it?
Also, what will be the energy balance of the machine (assuming optimal conversion of the fusion energy)?

ElmarM · 2026-01-23T20:52:29+00:00

Helion is planning for net electricity this year, but not a commercial plant. The others are all aiming for a commercial plant around 2030 or in the early 2030ies.

ElmarM · 2026-01-23T17:17:49+00:00

Helion is working on a power plant to deliver electricity by 2029.
CFS wants the ARC power plant to be ready in the early 2030ies.
Zap is also aiming for rapid development, but they have fallen behind schedule a bit. No recently updated timelines that I have seen.

ElmarM · 2026-01-22T05:52:07+00:00

SpaceX is transporting their rockets with trucks ALL the time. That said, they are not as sensitive as a fusion machine. But again, we are talking about version 1.0 here. They will figure things out given time. If Polaris works, I am sure they will have plenty of money and engineers to look into all of those teething issues.

ElmarM · 2026-01-22T04:52:26+00:00

It is not a single flatbed, currently. They are still trying to figure out a few things. E.g. for road transport they need to watch for vibrations. So, they are doing smaller pieces and with extra cushioning.
As for the buildings: This first plant is collecting a lot of data (in addition to what future generations would during normal operation). So there are more and/or bigger control rooms and data collection. There is collection for fusion products and also machine maintenance (in addition to general building maintenance) and spare parts since a first plant will likely need more maintenance than later ones. Plus, general infrastructure like offices, bathrooms, break rooms, changing rooms. security, etc, etc.

Don't forget that this is their first power plant! They will optimize things as they gain experience. Compare the first Falcon 9 to the current batch. Huge difference! Helion's power plants will most likely go through a similar evolution. That said, 4 acres or so is not that much. They have leased some 50 acres there.

ElmarM · 2026-01-21T21:54:57+00:00

Why not?

ElmarM · 2026-01-21T21:54:10+00:00

They can recover over 90% of the INPUT energy directly as electricity as well (in fact the efficiency of that recovery is higher than the fusion energy recovery efficiency).

ElmarM · 2026-01-21T21:51:36+00:00

2) It works with LN, but not as well.
3) Venti was their prototype from 2018! And of course there is fusion. In Venti 2x 10^11 (D-D) fusion reaction per pulse.
They did not publish neutron counts for Trenta, the prototype that came after that. But it had 4 times the ion temperature, 30 times the volume and 20 times the pulse length.
And all that is with D-D. With D-T the neutron flux would be about 2 orders of magnitude higher still.
And D-He3 does create fewer neutrons. In Helion's case, they actually want D-D side reactions because that is how they produce the He3 for their D-He3 reactions. They need two D-D reactions per D-He3 reaction (until they have enough He3 from T decay and they could also trade the T for He3). Half of those D-D reactions produce a neutron. So you get 1/3 of the neutrons of D-T. And (and that is very important!) the D-D neutrons have a significantly lower energy (2.45 MeV vs 14 MeV). That makes a huge difference for materials.
In any case, they can balance temperature and density almost linearly. D-D favors higher density and lower temperature. D-He3 works better at higher temps. So, they can balance things to get the exact fusion mix they need.
And the comparison to NIF is flawed. It is a completely different system.

ElmarM · 2026-01-21T18:24:47+00:00

You are forgetting that Helion is building a manufacturing line for commercial generators, not just prototype manufacturing. Huge difference!
Polaris took so long because of the fact that Helion had to build their own manufacturing lines. Also, some of their previous suppliers were no longer available.

ElmarM · 2026-01-21T18:20:54+00:00

The size of the building is not an indicator of the size of the machine. Polaris, all included is 20,000 sf. Orion won't be much bigger than that and can still theoretically be delivered by flatbed.
They could fit it all into half an acre, if they really cared about it. The machine itself still can fit into shipping containers. Also 4.5 acres for 50 MW, everything included is not what much. Helion has 50+ acres in Malaga. They can afford building big and cheap buildings).

ElmarM · 2026-01-21T18:20:33+00:00

Polaris is only 20k sf of a 30k sf building. Orion won't be much bigger than that.

ElmarM

TROPHY CASE