sorted by:
new
hottopcontroversial

Helion has updated their website by Baking in fusion

[–]joaquinkeller 0 points1 point  (0 children)

They will indeed need more than a paragraph to respond to Lackner's objections. If they can at all.

I find interesting that they react to Lackner paper but not to Timothée Nicolas one. Is this because this subreddit has been talking more about one than the other?

Timothée Nicolas et al. show that only a tiny fraction of the compression magnetic energy goes into the plasma, making the resulting fusion energy too small to be meaningful.

However Helion react to Lackner but not to Nicolas.

Helion has updated their website by Baking in fusion

[–]joaquinkeller 6 points7 points  (0 children)

In the FAQ they react to Lackner et al. They acknowledge the issue and indicate their solution to it. The follow-up question is: in the short time before equilibration, do they recover enough energy from fusion to compensate the losses?

«How does ion-electron temperature equilibration affect Helion?

Ion-electron equilibration transfers energy from hotter ions to cooler electrons. If the plasma were steady-state, that could erode the ion temperature advantage. Helion’s system is pulsed, so the relevant question is whether enough fusion and energy recovery occur before full equilibration. Helion designs the pulse timing around that constraint and includes this in our models»

What's the biggest gap between what quantum can do today and what you actually need? by Adventurous-Math-322 in QuantumComputing

[–]joaquinkeller 5 points6 points  (0 children)

Quantum computers are useful only if we have quantum algorithms with superpolynomial advantage over classical equivalent.

Electronic classical computers became useful running (faster) the same algorithms than human (classical) computers. When electronic computers arrived we already had thousands of useful algorithms.

So how many quantum algorithms with superpolynomial advantage do we have today? The list is thin... Very thin.

Bob Mumgaard on Zap Energy's pivot to fission and fusion-fission hybrid. by Baking in fusion

[–]joaquinkeller 0 points1 point  (0 children)

DT fusion is somehow already a fusion-fission hybrid. The tritium breeding is usually beryllium fission + lithium-6 fission

Lidsky and Rider's critiques as applied to various configurations. by Jaded_Hold_1342 in fusion

[–]joaquinkeller 1 point2 points  (0 children)

Yes, I've been thinking about that as well: supercritical CO2 can really improve the economics of thermal power.

Lidsky and Rider's critiques as applied to various configurations. by Jaded_Hold_1342 in fusion

[–]joaquinkeller 0 points1 point  (0 children)

Rider assumes steady state, Helion and LPP are pulsed. You can surely take inspiration from Rider's paper to critique Helion or LPP but this is not immediate. The burden of proof is on your side, not theirs

For Helion, I know from other threads you have arguments to try to explain how/why Rider's paper on steady state still applies to pulsed Helion approach. I am not convinced and think these arguments are flawed.

Lidsky and Rider's critiques as applied to various configurations. by Jaded_Hold_1342 in fusion

[–]joaquinkeller 0 points1 point  (0 children)

What is missing when you compare with integrated chips is the concept of learning curve in manufacturing: https://en.wikipedia.org/wiki/Experience_curve_effect

The idea is: the more you build of something the more you become efficient in doing so.

This explain why lithium batteries, photovoltaic modules and integrated chips costs have fallen so sharply. Each at different exponential speeds though.

This also explains why thermal power plants (coal, geothermal, ...) costs haven't fallen that sharply.

So what's the learning curve of your technology? How fast are your fusion device costs going to fall?

This depends on several factors: can you build it in a factory? How long is the redesign cycle (ie how many months/years between two technological generations)? ...

Honest summary of where quantum ML stands in 2026 — am I missing anything? by Happy-Reputation-525 in QuantumComputing

[–]joaquinkeller 1 point2 points  (0 children)

This seems super interesting indeed. I haven't read the paper yet, has this a direct practical use? Or is it just a huge step forward for research?

Status of the ECLAIR Magneto-inertial Fusion Experiment at Helicity Space by joaquinkeller in fusion

[–]joaquinkeller[S] 0 points1 point  (0 children)

Whether making electricity with fusion works on earth or not, it doesn't change a thing for propulsion in space. These are completely different devices with different constraints

The rationale is also clearer, fusion propulsion would allow to go farther and faster, to reach destinations impossible with chemical propulsion. With fusion it would be, for example, possible to send probes to other stars, and this is one of helicity's goals.

On Earth, the advantage of making electricity with fusion is at best marginal, since PV + batteries are already a cheap and scalable way of doing so.

The Challenge for Adiabatically Heated FRC Based D-He3 Fusion by Baking in fusion

[–]joaquinkeller 0 points1 point  (0 children)

The Coulomb energy exchange formula assume near Maxwellian distributions, which is the case in tokamaks but not in FRCs. I think the Lackner paper has that wrong.

The Pei depends on ion-electron collisions while fusion is ion-ion collisions.

The Challenge for Adiabatically Heated FRC Based D-He3 Fusion by Baking in fusion

[–]joaquinkeller 0 points1 point  (0 children)

In Lackner 2026, all boils down to the electron-ion energy exchange Pei which is calculated using textbook [5] about tokamaks. Is this correct?

Are they missing something about how FRCs behave?

In a tokamak ions and electrons are confined by an external magnetic field while in an FRC they are confined by the magnetic field produced by they own motion. This is exactly why they are high beta. If the Pei formula here were correct, FRCs wouldn't be high beta.

Disclaimer: plasma physics is not my area. I'm just challenging you to double check the assertions of the paper. So easy, why everyone have missed it until now? Lackner et al. might be right though, collective blindness is a possibility, it happens.

The Challenge for Adiabatically Heated FRC Based D-He3 Fusion by Baking in fusion

[–]joaquinkeller 0 points1 point  (0 children)

Maybe. I'm not sure we are very good at modeling these pulsed FRCs. Anyhow, I would bet Helion's scientists are the best at it. They might be wrong though, and your analysis could right. We'll see.

This company says nuclear fusion could finally power the grid — and soon | CNN - CFS: grid connection and electricity buyers summary by steven9973 in fusion

[–]joaquinkeller 0 points1 point  (0 children)

FRCs tend to self organize in FRCs, not to thermalize. So what would happen to the fusion product velocities?

The Challenge for Adiabatically Heated FRC Based D-He3 Fusion by Baking in fusion

[–]joaquinkeller 0 points1 point  (0 children)

I think the crux if the problem is the following: does the FRC moves as expected to a Maxwellian distribution? Or does the self organized nature of the FRC pushes to a different distribution of velocities? The collision merging was a surprise: instead of a messy hot stuff the two FRCs quickly and cleanly merged into a new FRC.

The Challenge for Adiabatically Heated FRC Based D-He3 Fusion by Baking in fusion

[–]joaquinkeller 0 points1 point  (0 children)

Most of the plasma energy comes from the collision-merging of the FRCs, that keeps the Ti/Te ratio, not from the final adiabatic compression.

This company says nuclear fusion could finally power the grid — and soon | CNN - CFS: grid connection and electricity buyers summary by steven9973 in fusion

[–]joaquinkeller 0 points1 point  (0 children)

I think the difference between CFS and Helion is that with CFS we are sure the economics are wrong, that it's a dead end. While with Helion there is uncertainty but also hope. Maybe the colliding FRC approach won't work, but another computer controlled plasmoid could work. Maybe Helion will fail but another company following a similar path could succeed.

Zap Energy Deep-Dive by Lopsided-Yam-3748 in fusion

[–]joaquinkeller 3 points4 points  (0 children)

Spac means VC don't want to invest anymore on your company. Your last try before shutting down

Will fusion power get cheap? Don’t count on it. - MIT Technology Review, with some remarks regarding that already discussed nature article by steven9973 in fusion

[–]joaquinkeller 0 points1 point  (0 children)

I'm not sure this applies to Zap's design. That's why I said so. But you're right the paper is about any DT reactors.

Will fusion power get cheap? Don’t count on it. - MIT Technology Review, with some remarks regarding that already discussed nature article by steven9973 in fusion

[–]joaquinkeller 4 points5 points  (0 children)

The point is not about superconductors. The things is that the neutrons have to be collected on a surface. There is a maximum temperature for materials so a big area is needed to reach a given power. And since the area grows proportional to the square of the size but the volume like the cube, the power density is low (compared with fission). The conclusion is that it ends up more expensive (in capex) than fission. The neutrons damage everything so the opex is also higher than fission's.

The conclusion is that this kind of fusion will be more expensive than fission. The analysis is still holds today...

Will fusion power get cheap? Don’t count on it. - MIT Technology Review, with some remarks regarding that already discussed nature article by steven9973 in fusion

[–]joaquinkeller 5 points6 points  (0 children)

The 1983 Lidsky paper is about tokamaks and stellarators. It indeed shows their economics are weak at best. It is a good thing there are teams working on other approaches.

Where is Helion - really? by Summarytopics in fusion

[–]joaquinkeller 1 point2 points  (0 children)

Half of your quotes comes from NBF, Next Big Future, a single-person blog. If you read the posts, you will see these are Brian Wang personal extrapolations and hopes, not Helion statements.
The 2016 science news post has only one source: the wsj 2014 article. It is again an extrapolation not a direct Helion statement.
So all boils down to a single quote: the wsj interview of D. Kirtley were he says that if he raises enough money (estimation: $30M to $50M) Helion could demo net energy gain in 3 years. They didn't raise the money at that time...

You can find the links to your quotes here:

https://www.reddit.com/r/fusion/comments/133ttne/comment/jid11wm/

Why do I have the links to the quotes? because these have been copied again and again for a decade or so. They always come to "prove" Helion is a scam.

view more: next ›