[MobiusHorizons]

I can imagine it would be reasonable for fusion scientists to not spend effort on the Heat -> electricity part. What I think the article is highlighting is that they are currently totally ignoring all the energy that goes into anything other than plasma, (ie the power to run magnets, vacuum pumps, or lasers), which from the examples given is on the order of 10s-100s of times the power delivered to the plasma.

This energy should be considered by fusion scientists, because it may end up invalidating certain topologies that can achieve a Qplasma > 1, but can't achieve a Qtotal > 1. For instance from the article, it seems like pulsed lasers are relatively inefficient at turning input energy into laser energy, which might mean they would need a QPlasma > 100 before QTotal aproaches 1. I don't know which of those inefficiencies are deemed to be fundamental and which are potentially improveable, but it could suggest the whole line of research is not worth perusing.

[willis936]

Qtotal doesn't affect the physics of the plasma. Qplasma does. Making a machine that burns plasma is expensive. Actually understanding burning plasma is necessary to build a reactor. This basic understanding appears to be lost on Sabine.