4 ms·

It’s practical proof that in a single pulse we can get more energy out than we put in. We do spend a shit ton of energy setting up the pulse, and we haven’t fig

It’s practical proof that in a single pulse we can get more energy out than we put in. We do spend a shit ton of energy setting up the pulse, and we haven’t figure out how to get that energy out and make electrons move, but it’s been proven possible. The “breakthrough” is the proof that it’s possible. Everything else is now optimisation and engineering, and needs mostly time, sweat and money.

maegul 4y ago
Yea, and I wonder how much our need, at a cultural level, for progress will factor into this. If we feel like we need to progress and can't go "backward" with our energy technology, there may just be an irrational impetus to make it happen. Solar and wind etc may just feel too "primitive" and nuclear too old and toxic and Chernobyl. Fusion though, once there's enough buy in and enough of a sense of it being doable, would fit our expectation of technological progress.
- pmontra 4y ago
  Culture bends to circumstances. When or where people can't cook or stay warm using the power sources they are accustomed to they go back in an instant to old ones. Logging and campfires, stoves, etc.
- ehnto 4y ago
  The practical reality is that solar and wind are still getting deployed en masse, people who want electricity don't really care what how science feels about progress etc. They just want their lights to turn on and for cheap. Since renewables are currently cheap, that's what we're deploying a decent amount of (depending on geography of course).
Retric 4y ago
Sort of. This milestone is liberating more fusion energy than photons used to start the reaction, but the energy source for the machine was electricity and it produced zero electricity. If you tried to convert the heat back to electricity you would be talking less than 0.1% of the electricity used being recovered at the other end.
HPsquared 4y ago
That was already proven in weapons tests in the 1950s (e.g. https://en.m.wikipedia.org/wiki/Castle_Bravo https://en.m.wikipedia.org/wiki/Castle_Bravo). The hard part is always building the machine to produce net energy gain, which is still 2+ orders of magnitude away.
- DennisP 4y ago
  The reason it looks that far away is that NIF uses lasers from the 1990s with only 0.5% efficiency. Equivalent modern lasers are over 20% efficient, which would put overall net energy gain only one order of magnitude away. https://physicstoday.scitation.org/do/10.1063/pt.6.2.20211020a/full/ https://physicstoday.scitation.org/do/10.1063/pt.6.2.2021102...
  - LarryMullins 4y ago
    > which would put overall net energy gain only one order of magnitude away. With modern lasers they would be closer to Q=1 without the funny energy accounting. But still several orders of magnitude away from commercially viable, which requires vastly greater efficiency than Q=1.
    - candiodari 4y ago
      Energy return on investment. Some oil extraction is currently at EROI=10, assuming EROI and Q can be made to be the same concept. Higher than EROI=50 is unheard of today, even 40 is pretty rare. EROI for this fusion method would be ~0.015. The worst fusion methods scales with the cube of the radius of the area that can be made to fuse. So we "only" have to get a 10x bigger area to fuse, or have the same area fuse for 10x longer (and make the facility not blow up or melt down from doing that). Working fusion is surprisingly close.
chasd00 4y ago
I wonder how the composition of the pellet was optimized. I'm sure the pellet was setup to make ignition as likely as possible. Now that they've accomplished that i wonder if parameters can be changed to up the efficiency of the reaction for energy output? Granted, optimizing for likeliness of ignition may well be the same as optimizing for energy output. Can they just up the mass of the pellet for a longer fusion reaction? Isn't additional stages in fission/fusion bombs just upping the mass with the result being higher yields? "higher yield" being a bit of an understatement as the range is like 100KT to 100MT (and beyond). Can a multi-stage pellet be formulated? Ignition of an outer pellet provides some energy to get a more powerful inner pellet ignited. /not even close to being a layman, let alone expert, on the subject
- floxy 4y ago
  >Can a multi-stage pellet be formulated? Ignition of an outer pellet provides some energy to get a more powerful inner pellet ignited. My understanding is that that is the whole point of the announcement. The initial laser induced fusion caused further fusion of the interior. That's why the gain is greater than one. And that's why there is excitement, the possibility is there to scale things up using larger/more massive pellets. To me, that's the real announcement, the laser initiated fusion created additional fusion. The whole break-even energy seems more like a red-herring. Also, with inertial confinement fusion you have the possibility of doing the harder fusions, (like aneutronic fusion), that magnetic confinement fusion would have a much harder time with.

maegul 4y ago

Yea, and I wonder how much our need, at a cultural level, for progress will factor into this. If we feel like we need to progress and can't go "backward" with our energy technology, there may just be an irrational impetus to make it happen. Solar and wind etc may just feel too "primitive" and nuclear too old and toxic and Chernobyl. Fusion though, once there's enough buy in and enough of a sense of it being doable, would fit our expectation of technological progress.

pmontra 4y ago
Culture bends to circumstances. When or where people can't cook or stay warm using the power sources they are accustomed to they go back in an instant to old ones. Logging and campfires, stoves, etc.
ehnto 4y ago
The practical reality is that solar and wind are still getting deployed en masse, people who want electricity don't really care what how science feels about progress etc. They just want their lights to turn on and for cheap. Since renewables are currently cheap, that's what we're deploying a decent amount of (depending on geography of course).

Retric 4y ago

Sort of. This milestone is liberating more fusion energy than photons used to start the reaction, but the energy source for the machine was electricity and it produced zero electricity. If you tried to convert the heat back to electricity you would be talking less than 0.1% of the electricity used being recovered at the other end.

HPsquared 4y ago

That was already proven in weapons tests in the 1950s (e.g. https://en.m.wikipedia.org/wiki/Castle_Bravo https://en.m.wikipedia.org/wiki/Castle_Bravo). The hard part is always building the machine to produce net energy gain, which is still 2+ orders of magnitude away.

DennisP 4y ago
The reason it looks that far away is that NIF uses lasers from the 1990s with only 0.5% efficiency. Equivalent modern lasers are over 20% efficient, which would put overall net energy gain only one order of magnitude away. https://physicstoday.scitation.org/do/10.1063/pt.6.2.20211020a/full/ https://physicstoday.scitation.org/do/10.1063/pt.6.2.2021102...
- LarryMullins 4y ago
  > which would put overall net energy gain only one order of magnitude away. With modern lasers they would be closer to Q=1 without the funny energy accounting. But still several orders of magnitude away from commercially viable, which requires vastly greater efficiency than Q=1.
  - candiodari 4y ago
    Energy return on investment. Some oil extraction is currently at EROI=10, assuming EROI and Q can be made to be the same concept. Higher than EROI=50 is unheard of today, even 40 is pretty rare. EROI for this fusion method would be ~0.015. The worst fusion methods scales with the cube of the radius of the area that can be made to fuse. So we "only" have to get a 10x bigger area to fuse, or have the same area fuse for 10x longer (and make the facility not blow up or melt down from doing that). Working fusion is surprisingly close.

chasd00 4y ago

I wonder how the composition of the pellet was optimized. I'm sure the pellet was setup to make ignition as likely as possible. Now that they've accomplished that i wonder if parameters can be changed to up the efficiency of the reaction for energy output? Granted, optimizing for likeliness of ignition may well be the same as optimizing for energy output. Can they just up the mass of the pellet for a longer fusion reaction? Isn't additional stages in fission/fusion bombs just upping the mass with the result being higher yields? "higher yield" being a bit of an understatement as the range is like 100KT to 100MT (and beyond). Can a multi-stage pellet be formulated? Ignition of an outer pellet provides some energy to get a more powerful inner pellet ignited. /not even close to being a layman, let alone expert, on the subject

floxy 4y ago
>Can a multi-stage pellet be formulated? Ignition of an outer pellet provides some energy to get a more powerful inner pellet ignited. My understanding is that that is the whole point of the announcement. The initial laser induced fusion caused further fusion of the interior. That's why the gain is greater than one. And that's why there is excitement, the possibility is there to scale things up using larger/more massive pellets. To me, that's the real announcement, the laser initiated fusion created additional fusion. The whole break-even energy seems more like a red-herring. Also, with inertial confinement fusion you have the possibility of doing the harder fusions, (like aneutronic fusion), that magnetic confinement fusion would have a much harder time with.