(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.

[–] Nastybutler 11 points 7 months ago (1 children)

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

[–] [email protected] 11 points 7 months ago (1 children)

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.

[–] dojan 2 points 7 months ago (1 children)

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.

[–] [email protected] 2 points 7 months ago* (last edited 7 months ago) (1 children)

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.

[–] dojan 1 points 7 months ago (1 children)

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.

[–] [email protected] 2 points 7 months ago* (last edited 7 months ago) (1 children)

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.

[–] dojan 2 points 7 months 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.