I guess I don't really get it. Nobody doubts that you can get a tremendous output of energy from a fusion bomb with modest inputs. This thing they've ignited is a tiny fusion weapon without a fission blanket and with a huge, inconvenient optical primary. I mean I'm all for science but I don't see the road from this to civilian fusion power as people generally understand the term.
Fusion energy breakthrough by Livermore Lab
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Re: Fusion energy breakthrough by Livermore Lab
#12The 457th "breakthrough" in fusion this year...
good, keep em coming.
Re: Fusion energy breakthrough by Livermore Lab
#13Didn't they claim this already in 2013? https://gizmodo.com/breakthrough-the-worlds-first-net-positi...
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Re: Fusion energy breakthrough by Livermore Lab
#14Didn't they claim this already in 2013? https://gizmodo.com/breakthrough-the-worlds-first-net-positi...
Last time, they got something like 80% return on the laser energy input, now it's over 100% apparently. And, they had trouble repeating that last record, so people were questioning how meaningful it was if it couldn't be repeated. Now they've been able to repeat it & improve on it.
Re: Fusion energy breakthrough by Livermore Lab
#15Re: Fusion energy breakthrough by Livermore Lab
#16The efficiency of the lasers is awful though and they will have to get at least 100x that energy yield for it to be a net power source. A lot of heat winds up in the laser glass and it takes it a long time to cool between shots so you are doing very good to make a few shots a day. A real power plant is going to need more like 10 shots per second. Heavy-ion fusion has been talked about since the 1970s and it seems muc…
Yeah, either heavy-ion beams or electrically-pumped excimer lasers seems like the path forward for the driver. Higher efficiency, higher repetition rate, possibly more robust. They also need to do away with holraums and switch to direct drive, to reduce target cost, ease alignment issues, and increase energy efficiency.
I don't hold out much hope for a practical, economical reactor from inertial confinement, but it's certainly exciting to see them achieve ignition & scientific breakeven, even if it's 10 years behind schedule. The one nice thing about ICF is that the energy gain shoots up dramatically once you cross the ignition threshold. That means they're arguably closer than tokamaks, even though both concepts need ~100x the demonstrated gain to get from where they are now to a workable reactor. (Ie, tokamaks have hit Q~0.3, need to get Q~30, vs ICF that has hit Q~1, needs Q~100).
Re: Fusion energy breakthrough by Livermore Lab
#17do I just wait until this gets walked back or...?
Re: Fusion energy breakthrough by Livermore Lab
#18The 457th "breakthrough" in fusion this year...
I would say there have been a handful of important milestones this year, but this I would consider a breakthrough. Most of the other stuff is overhyped for sure.
Re: Fusion energy breakthrough by Livermore Lab
#19It’s a real bummer to me that hype around fusion has faded so much because of the false hopes that this sort of thing barely registers on HN anymore.
Re: Fusion energy breakthrough by Livermore Lab
#20I hope I'm wrong, but this seems like a lot of other "firsts". I'm guessing the total (and I mean -total-, lasers typically aren't that efficient) energy put into this will be much greater than the output.
At least according to the TFA, it seems that the breakthrough is that they got 2.5 mJ out vs. the 2.1 mJ that was used to power the laser.
MJ, not mJ. 2.5mJ is roughly the energy of a single keyboard keypress. 2.5MJ is over half a kilo of TNT.
Fun fact that Wolfram alpha just informed me of: a phone uses between 10 and 20 MJ a year: multiple kilos of TNT. 4000mAh * 3.7V * 365: yep, it's about right.