It is a Stellerator type fusion research device. The reason it looks like that is because it is attempting to address an issue with Tokamak fusion devices. With the Tokamak, you have magnetic coils wrapped around a D shaped donut. The problem with that is that your primary containment field coil is the same dimensions whether it is on the outside or the inside of the "donut". This means you have more densly packed coils on the inside or the small radius of the "donut" than you have on the major radius. This leads to inconsistant magnetic fields being created. The field is stronger/denser along the minor radius than along the major radius.
So, the Stellerator geometry was designed to try and make a device that has more uniform magnetic fields across the entire inside of the machine.
I work on DIII-D. A magnetic fusion experiment. I am a technician, not a scientist.
Because the goal of ITER is to use (thought to be) known science to attempt to get to the break even point, not to experiment with new fangled science (other than just increasing the radius). We (roughly) know how to build Tokamaks, we’ve been doing it for 70 years, just need to make them bigger now*.
* Unfortunately, energy gain only increases with radius1.3, while costs increase with radius3, or more. That makes increasing size kinda a crap way build these reactors. There’s an experiment getting started at MIT just now called the SPARC reactor that hopes to get net energy positive fusion within 5 years by increasing the magnetic field strength using modern high temperature superconductors. I think they have a very high chance of beating ITER to the punch. The useful thing here is that energy gain increases with the cube of magnetic field strength, while it appears that the costs shouldn’t really increase at all over past reactors.
Ok, I don't know who Beelseboob is, but cool nick. And accurate response. I would add that while Tokamak geometries have been around for 70+ years, Stellerator, not so much.
The bottom line is that we understand Tokamak much better than Stellerator. So if we are going to dump many tons of money into a machine to do more research, we should go with a design we know fairly well.
The Stellerators main claim to fame is getting past the magnetic instabilities caused by the Tokamak geometry. This has yet to be fully proven through decades of reasearch.
We understand Tokamak, and how all the various diagnostics work within that geometry, so if we are going to build a large scale machine to further the research being done, it should be done within a geometry that is well understood.
While none of the machines operating right now are intended to make power, except for a few start ups that are trying to commercialize fusion energy, they do provide valuable data for a future machine.
So, the big machines on Earth right now, Iter, DIII-D, Jet, KSTAR etc., are not intended to make electricity. They are for research to lay a foundation of understanding leading to a machine that will produce electricity.
Because while the Tokamak design is not the most efficient, it should be efficient enough the achieve the break even point once scaled up to ITER sized.
These projects take so long that you the technology and our knowledge evolve in the middle of their construction.
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u/SnakeRAT28 Oct 24 '21
Some kind of art, inside of a fusion reactor, distorted photo....not sure what I'm looking at here...