4 ms·

Not sure about the low power output. With the caveat that I'm a nuclear engineer but not a fusion expert, from what I understand the deuterium density is actual

by gh02t 6y ago

Not sure about the low power output. With the caveat that I'm a nuclear engineer but not a fusion expert, from what I understand the deuterium density is actually quite high compared to plasma-based systems like tokamaks. NASA's press release says the deuterium density in their lattice confinement process is a billion times more dense than the plasma in a magnetic confinement system (https://www1.grc.nasa.gov/space/science/lattice-confinement-fusion/ https://www1.grc.nasa.gov/space/science/lattice-confinement-...), though I note it's not clear exactly what they mean. So that is promising. If they can figure out how to sustain a chain reaction or otherwise extract a net energy gain it might still be useful as battery even if they end up having to put more energy to fabricate the fuel in than you get out. Something like how current RTGs are used, except I expect it would have much higher energy density. This is all speculation, however, and there is a lot of work left.

DennisP 6y ago
Interesting point. I just guessed at a plausible reason to focus on deep space, I don't know whether that's actually the case. It seems like it couldn't have too much power density though, or the solid lattice would melt.
- gh02t 6y ago
  The lattice melting is probably not a major issue, you just have to cool it to remove the heat as it's generated. At a basic level you face the same problem in a fission reactor and the solution is straightforward -- extract the heat into some sort of working fluid (or gas) to keep the fuel from melting. Fission reactor fuel is actually not even terribly dissimilar to the stuff described in the article, most often it's fabricated as a sintered powder. Again, this is super early so this is all wild speculation, but generally engineering challenges are easier to solve than fundamental science problems. Of which there remain a few. That said, most of the problems with MCF are engineering issues and we still don't have that working yet either so...

by gh02t 6y ago

DennisP 6y ago

Interesting point. I just guessed at a plausible reason to focus on deep space, I don't know whether that's actually the case. It seems like it couldn't have too much power density though, or the solid lattice would melt.

gh02t 6y ago
The lattice melting is probably not a major issue, you just have to cool it to remove the heat as it's generated. At a basic level you face the same problem in a fission reactor and the solution is straightforward -- extract the heat into some sort of working fluid (or gas) to keep the fuel from melting. Fission reactor fuel is actually not even terribly dissimilar to the stuff described in the article, most often it's fabricated as a sintered powder. Again, this is super early so this is all wild speculation, but generally engineering challenges are easier to solve than fundamental science problems. Of which there remain a few. That said, most of the problems with MCF are engineering issues and we still don't have that working yet either so...