D Tibbets wrote:The problem is the praticality of the aproach. This can also be applied to the ITER Tokamak approach.
I fully agree with you on that, Dan.
D Tibbets wrote:The other example is the NIF, sort of, if you ignore many aspects. The laser input that directly contributed to compressing and heating the DT fuel was less than the fusion output. This does ignore the laser energy that expended doing other things, like heating and exploding the horloium (sp?). Only a small portion of the laser input contributed to the DT compression and heating.
Yeah and lets not forget what went into making that "Hohlraum" in the first place...
D Tibbets wrote:Any benchmark is open to interpretation.
A Q>one is not useful for energy production, actual performance would actually need to exceed a Q>3 or so for a net positive electricity generation via a steam cycle. As such, that is the real minimal target. For net profitable fusion electricity production a Q >5 may be needed.
Direct conversion has the potential to help a bit with the conversion efficiency and overall economy of the powerplant (if we can get it work), otherwise, ladajo is right and a Q>10 might be needed.
D Tibbets wrote:In some situations a Q < one may suffice.
I think a good example for that would be fusion-fission- hybrids.