Wendelstein 7-X: 8 min Plasma with 1.3 GJ Energy Turnover [video] | Hacker News Reader

Wendelstein 7-X: 8 min Plasma with 1.3 GJ Energy Turnover [video]

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AFAIK this is the proof that engineering has figured it out to have real stellarator fusion energy become a reality. Stuff works. It can keep plasma going for minutes as you wish. Now its the task of scaling I guess?

I have hope that fusion energy is indeed only a few years away now, not always some decades. It would be just in time so to speak. Can we throw like 1/10 of the US military budget against this tech and have it solved?

Keeping plasma going and actually having fusion are two different things. This is an important step to be sure but the Wendelstein is very much an experimental reactor. It's not meant to be something that will ever make large amounts of electricity.

Also note that the Wendelstein 7-X project started planning in 1980 and assembly took from 2005 until 2014. A US reactor experiment (the NCSX) was cancelled in 2009 because they couldn't get the required mechanical precision even in a lab setting. Even if we manage to solve the remaining technical challenges to sustained fusion in only five years (ie WAY ahead of the experimental schedule), building a power plant sized version would definitely take a decade or two including all the planning and actual construction.

More budget will probably help speed up the timeline somewhat but probably not that much. If you truly had 1/10th of the military budget to spend you could probably get a much bigger bang for your buck if you spend it on solar panels, batteries and on shoring up coastal defences/stormwater systems/building insulation/etc etc etc. The boring stuff, rather than the "silver bullet" projects like fusion power plants.

This was a plasma physics experiment to prove continous operation. Apparently going from 8 min to much larger timespans is less of a leap now.

Next stop in research: divertor design. Right now the divertor is still a challenge, as it heats up too much when the plasma gets hotter. You can see it in the video, the area that gets really bright in IR.

After the divertor is figured out, the blanket comes next. Neutron embrittlement of the structure is another issue. So power generation is still way out there.

Still, a great day for plasma physicists over the world. Decades of hard work went into this. Congrats!

It's not clear yet that fusion is a desirable source of energy. It sounds quite expensive: You need a high tech gizmo running a plasma and steam turbines to turn the heat into electricity. I'm doubtful that this can be cost-competitive with renewables+storage.

well to be fair, _large scale_ storage is also far from being a solved problem. Renewables are already exceptionally good to create energy and even getting more efficient… but the „on-demand“ part is the difficult one.

Fusion might just be the clean „baseline“ supply we need

Hydrogen is a proven, scalable technology for storing large amounts of energy. Power sources with high capex like nuclear and (presumably) fusion are incompatible with variable generation like renewables. Running them only makes economic sense when you run them at 100% all the time.

Depends on the fusion process and reactor. There are ones which omit the steam step by directly using the charged particles, turning them into electricity.

In theory, OFC.

You forget the applications this would have. Every fusion reactor we have, even ITER, would easily fit into an aircraft carrier. The W7-X can fit in a super-yacht sized vessel, and give it enough power to fly to the moon (not in a convenient/usable form, but certainly enough).

And yeah, so can a nuclear reactor of course, but if it manages to blow up halfway it would poison half the earth. Yet fusion reactors are safe.

What if we told NASA engineers they can use a gigawatt of power to drive ion engines?

The applications of this kind of power go far beyond keeping apartments warm.

I also posted this earlier with English article instead of the German video description

https://news.ycombinator.com/item?id=34924872

The video in the posting has both German and English video description

Do I understand correctly that no actual fusion took place? This just heated the plasma using an external power source as a test.

Here's a related article explaining the most recent test;

https://phys.org/news/2023-02-power-plasma-gigajoule-energy-...

Fusion reactor R&D generally avoids actually starting a fusion reaction unless they're ready to trash the reactor: current reactor designs can only manage D+T fusion, which generates a shitload of neutrons and leaves the reactor interior structures highly radioactive, making modification for further experiments problematic. (No-one is anywhere near achieving the energies needed for aneutronic fusion.)

For example, the JET (Joint European Torus) Tokamak at Culham began operation in 1983 but experiments with tritium only started in 1991; maintenance and upgrades after 1998 relied on a remote handling system as it was no longer safe for human technicians to work inside the reactor containment in shutdown.

https://en.wikipedia.org/wiki/Joint_European_Torus

D-T definitely trashes the reactor, but D-D generates fewer neutrons, so human maintenance is generally OK afterwards. C-Mod at MIT ran this way for a while. You just needed to wear a dose meter.

Small nit if you've never seen it written down, they're 'dosimeters'.

Polywell reactors have been doing D-D fusion since 2005, and measuring very few neutrons produced.

Is polywell dead? So little news.

Seems they concluded that it doesn't scale up. Can't find the source now.

Lots of R&D uses deuterium, the neutron output is lower-energy and a handy diagnostic. Even hobbyists with fusors run on deuterium. Getting net power with deuterium is harder than D-T, but just fusing some deuterium isn't hard.

The same goes for aneutronic fuels, as long as you reach the necessary temperature. Helion for example claims to have achieved a significant amount of D-He3 reactions. LPPFusion has published research saying they've achieved boron fusion temperatures, though not with boron fuel, or the triple product needed for net power from boron. (They're using deuterium though, and getting neutrons.)

ONe of the issues with Fusion: those neutrons mean it isn't the infinite clean energy source: using the reactor makes nuclear waste from the reactor vessel.

Also, even if a viable fusion reaction is produced, it has the same problem as fission reactors: you have to be price competitive with grid storage and load levelling reactors. I can almost guarantee that fusion will never beat solar/wind. Maybe they'd get away with not being NIMBY'd like the fission reactors and overregulated, but if they don't, costs go up.

I’m no physicist, but I’m pretty sure presence of plasma in these gizmos indicates fusion. I think though you’re asking if it was a self-sustaining reaction, and my impression (could be wrong) they did the ignition and they are stress testing the device and it’s heating and cooling systems.

There are a lot of relatively cold plasmas that don’t indicate fusion. Well, sure, maybe a few particles defy the odds and fuse, but really you’re seeing basically none unless the heat and density get high enough.

Unless they mention fusion, they are likely using test plasma that isn't going to fuse.

You can create a plasma in your microwave, that doesn't mean there is fusion.

You can buy an inexpensive plasma cutter at harbor freight that is happy to generate as much plasma as you want (while cutting metal). It definitely isn’t doing any atomic fusion anywhere.

It’s also what arc welders weld with.

Plasma is ionized gas (hence conductive), the ‘fourth state of matter’ and while usually hot, it doesn’t necessary have to be.

[https://en.m.wikipedia.org/wiki/Plasma_(physics)]

Presented in the context of “in these gizmos”. I did not say all plasma is fusion.

Most of these will be using plasma which is not fusing most of the time for testing, validation, etc.

Fusing plasma makes a lot of neutrons which cause problems, including irradiating things.

I believe this was an experiment to see that they can put a lot of energy into the reactor, and take a lot of energy out of it as well. Both of these are necessary criteria for a power plant.

Yes Wendelstein 7-X is not intended to produce fusion, it's an experiment to evaluate the stellarator concept.

They do plan to fuel it with deuterium and run it over 100 million degrees. They'll get fusion neutrons out of that. What they don't plan is deuterium-tritium fuel or a net power attempt.

https://euro-fusion.org/devices/wendelstein-7-x/

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