Largest nuclear fusion reactor is finally completed | Hacker News Reader

Largest nuclear fusion reactor is finally completed

livescience.com

8 pointsBrajeshwar20 comments

ITER is nowhere near "completed".

And it's already out of date because it doesn't use high-temp superconductors.

Not that HTSCs would make tokamaks competitive.

I was recently listening to a researcher talking about ITER. He claimed that there is currently no technology to shape high temperature superconductors into usable coils. Reason was their mechanical properties, namely fragility. He also claimed that all commercial fusion reactors are either using those or He3 which would need to be mined from the moon.

Helion would make their own 3He, by DD fusion. No lunar mining needed.

Yeah and where are those over unity results of their test reactor?

The other thing is that we do not care as much about the fuel, but the sheer masses of liquid helium as coolant. That reactor is not designed to capture the helium made for this purpose while staying energy efficient.

Helion has not yet built a reactor that would achieve the conditions needed for net energy generation. I hope the person he was talking to was talking about prospective reactors, not currently existing ones, as the latter is the null set.

Helion's design doesn't use superconducting magnets of any kind.

The claim about the second is correct, the first not quite since there are a few mid temperature superconductors that do work in liquid nitrogen, and REBCOs are mechanically good enough. Their problem is all the rare earths - and to make a magnetic containment fusion reactor you need truly massive coils. So you face a problem in price and availability of the materials...

> Their problem is all the rare earths

The fraction of mass in a HTS magnet that is rare earth is surprisingly small. Most of the mass is mechanical support, or substrate on which the thin HTS film is deposited. The entire ARC reactor might contain 10 kilograms of REBCO (2015 paper), out of a reactor mass of over 7 gigagrams.

https://arxiv.org/pdf/1409.3540

As compared to which demonstrator that uses HTS? The people at Tokamak Energy are very nice, but the technology is far from ready.

If that is your standard, then everything we make or build is outdated right out of the gate because there are always fancy new materials that are better for whatever property you think you need. They are also: much more expensive, usually much more difficult to make, not really well known (there is still quite a lot of research being done on REBCOs), and nowhere near ready for any kind of industrial process.

All the research in the area is for the next reactors. It’s good to look ahead and to know that there are several improvements coming, but it’s not realistic to expect them to be here already.

Indeed, the byline tells the truth: "ITER, a $28 billion fusion reactor in France, has finally had its last magnetic coil installed."

Just to nitpick, the “Byline” is ‘By Ben Turner’

What you are looking at there is a “standfirst”

Thanks for this nitpick as I did not know these terms

Sadly the article does not say what is going to take those 15 years. I know that the underlying reason for the delays is that the ITER staff have very comfortable taxpayer-funded lifestyles with no sense of urgency whatsoever, but still would be interesting to know how they are justifying the timeline.

Very long article with no news content.

I would not at all be surprised if the timeline for coming up for the justifications for the delay as a significant impact on the delay

Related ITER: World's largest nuclear fusion project begins assembly (669 points, 4 years ago, 449 comments) https://news.ycombinator.com/item?id=23979608

Import to remember this is a research reactor!

You can’t really do research with something you’re not trying to run.

but why?

my guess is scientists don’t wanna risk with Y2K38 causing blow up https://en.wikipedia.org/wiki/Year_2038_problem

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