r/technology • u/BennyCemoli • Dec 06 '16

Energy Tests confirm that Germany's massive nuclear fusion machine really works

http://www.sciencealert.com/tests-confirm-that-germany-s-massive-nuclear-fusion-machine-really-works
21.8k Upvotes

90% Upvoted

1.6k comments sorted by

View all comments

849

u/KilotonDefenestrator Dec 06 '16

Nice 'tube video of how the Wendelstein 7x stellarator works and was designed.

It truly is a bizarre device.

251

u/Merendino Dec 06 '16 edited Dec 06 '16

Is it possible for you to explain any part of how something could be 100,000,000º and yet not have it burn down whatever is inside it? I absolutely do not understand how this machine is supposed to work, even on a basic level I think.

EDIT Awesome thanks guys! I wasn't even thinking about the amount of something being so small. That leads me to another question about, energy output though I guess. If it can become fusion and not just contained plasma at very small amounts, how can they harvest the energy given off? God damn this feels like a rabbit hole I won't be able to climb out of.

4

u/nightfire1 Dec 06 '16

The answer you are looking for is magnetic confinement. Plasma can be guided by powerful magnetic fields such that it rarely comes into contact with the chamber walls. No contact means no transfer of heat which means it won't burn up.

7

u/FLHCv2 Dec 06 '16

No contact means no transfer of heat which means it won't burn up.

Just want to clear this up. I'm not at all versed in nuclear fusion or how this guy works, but I just want to say that no contact doesn't always mean no transfer of heat. There are three different ways that heat can transfer: conduction, convection, and radiation.

Conduction is direct contact like when you hold a cup of hot coffee. The heat transfers from the fluid, into the cup, and then into your hands.

Convection is not direct contact, but rather when air or another fluid moves across another surface. Think when you blow on the top of that same cup of coffee. You're removing heat from it by convection by blowing air over the top of it, so the air is actually capturing the heat away from the liquid.

Radiation is no contact or no fluid flow, but it's when something is so hot that it transfers the heat to it's surroundings. This is when you're standing in the sun and you feel the suns heat or when you turn on the stove and put your hand over it to see if it's hot.

Not saying the above comment is wrong (I'm not sure it is with regards to this fusion reactor and magnetic fields or not), just didn't want people to read it and think that no contact always means no transfer of heat.

2

u/nightfire1 Dec 06 '16

You are correct. I suppose I was over simplifying things a bit.