[abefetterman]

The other efforts you mention are much further from having Q>1 (energy producing) fusion. FRCs and focus have not even reached Q=0.000001 and have little theoretical basis for being power producing. Stellerators have their own problems as well. Tokamaks have achieved Q=0.69, and so ITER has very little risk of missing its goal of Q>1 if it does get constructed and run DT.

I agree that fusion is severely underfunded, and that it is dangerous for us to put all our eggs in the Tokamak basket. And this article is pretty strange for its fixation on DEMO which at this point might as well be made of unicorn horns. But ITER was proposed and is supported by a huge number of scientists for a good reason: it's the best way for us to hit a goal that fusion science has been dreaming of for 50 years, that is key to understanding and designing real fusion reactors.

[IanCal]

The ARC reactor is a tokamak design though, just (I appreciate the work this word is doing in this sentence) smaller and with much more powerful magnets. They quite explicitly want to not have a different type of reactor.

[shaqbert]

Problem w/ the ARC reactor is that it is just a design. The real life engineering challenges are still daunting. E.g. for the supra conductors at the Wendelstein 7-X, which provide a much less powerful magnetic field, just assembling and connecting the supra conductor cables for each module was a mind blowingly complex and fickle process that was described at length in this (unfortunately German) super awesome podcast [0].

[0]: http://alternativlos.org/36/

[abefetterman]

ARC is not designed to be cheaper or faster to build than ITER. Its purpose is closer to that of DEMO (engineering breakeven). ITER data will be critical for verifying the ARC design.