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Nuclear fusion reactor in South Korea runs at 100 million degrees C for a record-breaking 48 seconds (www.livescience.com)
submitted 2 years ago by [M] to c/science@lemmy.world
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48 seconds. I predict a glut of helium. balloons for everyone

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[–] 68 points 2 years ago (3 children)

48 seconds at those temperatures is no joke, that is pretty amazing. I didn’t see the article elaborate on what the current limiting factors are for pushing beyond 48 seconds. Like I wonder if it’s a hard wall, a new engineering challenge, a tweak needed, etc. this is the reactor that set the last record so they are doing something really right.

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  • [–] 35 points 2 years ago (1 child)

    (The article touches on this bit a little) I was watching something about fusion the other day and it seems that it is super tricky to keep the magnetic field balanced in a way that keeps the plasma in a proper toroid. Not only does it need to keep the correct strength, it has to fight against random turbulence. This is critical to start the reaction, but also to maintain it.

    Also, they gave some other physical limitations in the article as well:

    To extend their plasma's burning time from the previous record-breaking run, the scientists tweaked aspects of their reactor's design, including replacing carbon with tungsten to improve the efficiency of the tokamak’s "divertors," which extract heat and ash from the reactor.

    Basically, it's the container that has limitations as containing a pseudo-sun probably isn't easy.

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  • [–] 11 points 2 years ago (1 child)

    According to another commenter the heat generated is 7 times that of the core of the sun. Considering we use the sun in sci fi to destroy anything that can't be destroyed by other means, controlling that level of heat seems like a real challenge

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  • [–] 11 points 2 years ago (1 child)

    Yeah. Actually using that heat is the next challenge, I suppose. If I am not mistaken (and I am often mistaken), they are not actually using the reaction to power the reactor yet.

    It's all math, basically. If they measure more energy coming out than they put in, it's considered a win.

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  • [–] 2 points 2 years ago (1 child)

    How would they use it to power a reactor? Is it like a regular nuclear reactor where you essentially boil water to power a steam turbine?

    I swear a part of my inner child died the day I found out that nuclear reactors are essentially big kettles.

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  • [–] 2 points 2 years ago* (last edited 2 years ago) (1 child)

    It's likely going to create steam, just like a reactor today. It is a very effective way to turn a turbine for a generator, after all. All the bits that actually start and maintain the reaction need fuck tons of electricity, so the reaction can literally power itself when attached to a generator.

    While there are a ton of formulas for converting energy from heat, to steam, to mechanical energy and then into electricity, it's all basically the same: more power out than you put in is a good reaction.

    Almost forgot, water is dual function. It cools the equipment and it acts as an energy transport. I believe ammonia is more efficient in some circumstances, but water is better for obvious reasons.

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  • [–] 1 point 2 years ago (1 child)

    Yeah, I mean it makes sense. My inner child wants there to be some sort of magic that splits the atomic nucleus (or in the case of fusion... well you know) and harnesses the energy through some sort of fancy magical-to-us-commonfolk process.

    Kettles are great, but not whimsical or fantastic.

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  • [–] 2 points 2 years ago* (last edited 2 years ago) (1 child)

    How the heat is generated is still wicked-cool and is basically magic. Think about it this way: We are holding a toroid shaped micro-sun in place with magnets. Those magnets need to be adjusted hundreds of times a second to keep everything in its place. Sure, it just boils water, but how it boils water is where the real magic is.

    We are building atoms by taking control of the core of a star.

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  • [–] 2 points 2 years ago

    That's fair! I'm not trying to downplay the accomplishment at all. In that way even nuclear fission is really cool.

    It was just a big dissilusionment moment for me way back when I learned how the electricity is actually generated.

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  • [–] 27 points 2 years ago (1 child)

    Last one I read about is just constantly and very quickly (far quicker than human abilities) adjust the magnetic field around the plasma in order to keep it stable and in place. They've been (or at least one team was) using AI to go over data and control and predict the field adjustments, because only reacting after the plasma starts to move hasn't been quick enough.

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  • [–] 6 points 2 years ago (1 child)

    Yes, that'd be TAE technologies.

    The algorithm was called the optometrist, it was paired with a human operator to more quickly converge on the correct settings for stable plasma by having the machine randomly tweak various meta-parameters, while the human would generally decide whether the current settings were "better" or "worse" than the previous pulse.

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  • [–] 2 points 2 years ago (1 child)

    I wonder if there isn't a stable chamber shape that promotes turbulence in a controlled manner in order to prevent it getting out of hand? A little bit like the dimples on a golf ball create micro pockets of turbulence promoting laminar flow.

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  • [+] -31 points 2 years ago (2 children)

    They most likely ran out if liquid helium as the world is running out of the stuff at an alarming rate

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  • [–] 22 points 2 years ago (1 child)

    Fusion uses hydrogen and produces helium

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  • [–] 7 points 2 years ago* (2 children)

    They use liquid helium to cool the super magnets...

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  • [–] 10 points 2 years ago* (1 child)

    Sure, but why does that mean they must be losing the helium each time? I don't know anything about liquid helium and super conductors, but I know I don't need to replace my radiator fluid just because it cooled my engine.

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  • [–] 0 points 2 years ago (1 child)

    Once used, it need to be cooled down to -252c to be reused. Not like a closed loop of oil

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  • [–] 16 points 2 years ago (1 child)

    Alright, did some research, first off you're wrong about this being the reason even if this was a plausible reason. The real reason is the ash and heat divertors failed.

    Second, you don't even need liquid helium for super conduction. Here's a few closed loop helium gas coolers that get to 10 kelvin. They need to be refilled on the scale of years, not from a single test.

    https://www.arscryo.com/closed-cycle-cryocoolers https://stirlingcryogenics.com/products/closed-loop-helium-gas-cooling-system/

    I get you care deeply about helium loss but this is the last thing you should be accidentally spreading misinformation about. This process literally creates more helium then it uses.

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  • [+] -9 points 2 years ago (2 children)

    I didn't say they did, just said probably, I'm just a stupid redneck.

    Oh and how do we capture said multi thousand deg helium?

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  • [–] 2 points 2 years ago*

    Oh and how do we capture said multi thousand deg helium?

    By cooling down the air that contains it until it's liquid, then distilling that. Actually a standard process though usually you freeze down natural gas not just random air, it's quite helium-rich.

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  • [–] 9 points 2 years ago (1 child)

    This is such a ridiculous comment. I can literally go on Amazon and buy some helium right now. You really think if that's possible, a cutting edge research lab would run out of the stuff?

    Sure, it's limited and getting scarcer, but no one's running out yet.

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  • [+] -26 points 2 years ago* (1 child)
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  • [–] 16 points 2 years ago (1 child)

    That doesn't mean that they didn't have enough. The world being in the process of losing helium as a whole doesn't mean these researchers "ran out" of it. If they knew they needed it, they would have purchased it, so unless the world has run out of helium already then they didn't run out of it. You act like noone there could calculate exactly how much helium this uses per second and just buy x seconds worth of helium.

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  • [+] -25 points 2 years ago* (last edited 2 years ago) (1 child)

    OK let me rephrase, they ran out of usable liquid helium. You do realise LH is the coldest known substance known. If you have 5L of usable LH once you use the 5L and turn it into a gas it is no longer -254c A sing use of an MRI uses 2000L at say the low end of cost of $30 so $60,000 and that is at room temps now add a few thousand degrees....

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  • [–] 22 points 2 years ago (1 child)

    A single use of an MRI doesn't use 2000 liters, that is the upper end of a hospitals ENTIRE supply of helium. On average an MRI users 70 Liters per MONTH of operation. You're literally just spewing bullshit at this point, have a fun time being completely misinformed on things that upset you greatly, I'm going to go play games

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  • [+] -19 points 2 years ago (1 child)

    You are right. In a sense, they have to reclaim the helium. It takes 2,000L to run it, they reclaim it compress/cool then reuse it. That 70 L/month is what they loose after use.

    Do some reading before being an ass

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