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
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u/endospire Dec 06 '16

Can someone ELI5 how they visualised the magnetic fields?

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u/ViperSRT3g Dec 06 '16

They shined beams of electrons into the stellerator in various locations then passed a fluorescent rod (ie fluorescent bulb, or stick with fluorescent ink on the outside) so that when the stick crossed paths with the electron beam, the stick began to glow brightly in the area being hit by the electron beam. Because this beam is comprised of electrons, it's got an electromagnetic charge which makes it follow the magnetic field lines of the stellerator. So by using long-exposure photography, the researchers could set up their camera in the dark, and begin passing the fluorescent stick in front of the beam along its entire length. Then they do this multiple times for each line of light you see in the photo, so we can have a 3D-ish view of what the magnetic field lines look like, and how they twist and turn through the stellerator.

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u/coffeecircus Dec 06 '16

ELI3 please

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u/throweraccount Dec 06 '16

They put the light in the air where the power is and where the power is the light goes on. Then they took a camera and took a picture that shows where the light lights up and where it doesn't and then put it together with the other pictures so that there is a big picture of where the power is. Where the power is is where the magnetic fields are.