Talk-Polywell.org

Sabine Hossenfelder on nuclear fusion

https://www.youtube.com/watch?v=LJ4W1g-6JiY

She supports fusion, but believes it is much further away than popularly believed. Her main point is "Q" (breakeven) as popularly reported compares energy input to energy output when what matters is the total: not just the energy injected into a reactor, but the total energy cost of that injection.

Fascinating, but grim considering the enthusiasm Polywell generated circa 2007 which was the reason I first visited here.

Is Sabine's analysis too narrow? Focusing, as she does, on NIF (laser/implosion) and ITER, and not on the wild diversity of other approaches (reverse-field, dense plasma focus, that crazy one with pistons and molten metal, and polywell). For example, Sabine mentons the inefficiency of heat-to-steam-to-electricity, and does not consider the aneutronic possibility of fusion directly to electricity (fusion to X-rays to electricity, or fusion to beta parties to electricity, or however that goes).

Put another way, has Sabine rightfully called "bullshit!" on all the fusion efforts promising proof of practical plants any day now?

- Charles

PS... As will be obvious to most readers here IANAP (not a physicist).

She speaks as if the big government science projects are all that there is. It is misleading (to be kind). However, she is correct in that those projects mislead the governments funding them if they are not making clear that there is a conversion aspect that is important.

On the other hand the other private investor funded projects are clear about the conversion of plasma energy to electric energy requirements and Sabine seems to be completely ignorant about these other projects and does not address them (IMO she is just another person making money on Youtube, good for her, does not make her an authority though).

To contradict her assessment of fusion progress, Helion already has demonstrated the direct conversion of fusion power to electric power at 95% efficiency, and further, is targeting 2024 for net conversion to electric power with a fully funded project and with 6 previous successful sequentially scaled prototypes to back up their projection.

That's cheerful! Thanks.

Do I read correctly that Helion's plans are based on Helium-3 fuel?

I recall the renewed interest in landing on the moon might be to harvest Helium-3.

Seems like most people will lie to your face to protect their livelihood. I think she’s right, the confusion over Q is deliberate where it helps.

However, this is mostly common knowledge, so doesn’t ‘blow up’ anything, I think.

Worth thinking about what the ITER ‘industry’ does when/if Helion generates net power. I doubt they will walk quietly into that dark night…

And thanks for posting the video!

CharlesKramer wrote: ↑

Mon Jun 20, 2022 2:40 am

Do I read correctly that Helion's plans are based on Helium-3 fuel?

I recall the renewed interest in landing on the moon might be to harvest Helium-3.

Here's what Helion has stated:

Helion produces helium-3 by fusing deuterium in its plasma accelerator utilizing a patented high-efficiency closed-fuel cycle.

Helium-3 has, historically, been very difficult to produce. Scientists have even discussed going to the Moon to mine helium-3 where it can be found in much higher abundance. Helion’s new process means we can produce helium-3 (no space travel required!)

Sabine is riding on the anti- nuclear train which is typical for Germans. She is also focusing on ITER.
There are different definitions of Q and she is cherry- picking one that suits her agenda.
ITER's Q is generally legit, but it won't produce any electricity, which was never the goal for it anyway. It is an experiment, not a power plant.
She is also ignoring all of the advances made in the fusion- field since ITER was designed.
Generally, I would give her 1 Star for that video. Unfortunately people keep spreading and quoting it.

For more information on definitions of Q, check the paper by Scott Hsu and Sam Wurzel:
https://arxiv.org/pdf/2105.10954.pdf

Skipjack wrote: ↑

Mon Jun 20, 2022 8:34 pm

For more information on definitions of Q, check the paper by Scott Hsu and Sam Wurzel:
https://arxiv.org/pdf/2105.10954.pdf

The final version of this paper has been published in Physics of Plasmas as open access, so it can be downloaded here: https://doi.org/10.1063/5.0083990 .

I don't know if she is riding anti fusion agenda, but as a "theoretical physicist" she should stick to theories and leave engineering to Engineers.