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Yes. In nuclear fusion, "ignition" means that you get more energy out than the lasers impart. This is the first time anyone has pulled that off in decades of t

by teach 4y ago

Yes. In nuclear fusion, "ignition" means that you get more energy out than the lasers impart. This is the first time anyone has pulled that off in decades of trying, which is a big deal. But practical nuclear fusion would of course require that you get out more energy _from the entire system_ than you put in, and getting there will require even more problems to be solved. But now at least one obstacle has been overcome!

JumpCrisscross 4y ago
> "ignition" means that you get more energy out than the lasers impart. This is the first time anyone has pulled that off in decades of trying, which is a big deal. The term is refreshingly intuitive. For decades we've been striking stone and flint. Sparks. We just got a bit of kindling going. It's no bonfire. But it's a big step forward.
WithinReason 4y ago
>This is the first time anyone has pulled that off in decades of trying, which is a big deal. Are you sure of that? This is from 2014: https://arstechnica.com/science/2014/02/giant-leap-for-nuclear-fusion-as-scientists-get-more-energy-out-than-fuel-put-in/?itm_source=parsely-api https://arstechnica.com/science/2014/02/giant-leap-for-nucle...
- falcor84 4y ago
  Quoting from the article you linked to: Hurricane’s current output, although more than the hydrogen fuel put into the reaction, hasn’t yet reached the stated goal to achieve “ignition," where nuclear fusion generates as much energy as the lasers supply. At that point it might be possible to make a sustainable power plant based on the technology.
- tingletech 4y ago
  from your article: > Hurricane’s current output, although more than the hydrogen fuel put into the reaction, hasn’t yet reached the stated goal to achieve “ignition," where nuclear fusion generates as much energy as the lasers supply.
darksaints 4y ago
How do fusion bombs achieve "ignition"? It's not with lasers, right? Also, couldn't the net energy from the ignition be used to continue the reaction, so you only need the lasers for startup? Sorry for the newb questions, just curious.
- scarier 4y ago
  With a fission bomb. Don’t have a good explanation for your second question, although I think the short answer is “not with the way the Livermore experiment was set up.”
- jboy55 4y ago
  Caveat: This comment is derived from publicly available info. An H-bomb is a two part bomb. The primary bomb is a implosion plutonium bomb similar in make to the nagasaki/trinity bomb. It is theorized the Xrays from that bomb are focused on a secondary cylinder of uranium-238 that has a core of hydrogen and/or lithium. The Xrays ablate this casing at such intensity that the inward force (the opposite force of the ablation) is strong enough to propell the casing inwards at 300 km/second. This squeezes the hydrogen/lithium and causes fusion which releases a tone of energy, but more importantly a huge amount of neutrons. These neutrons cause the 238 in the casing to fission releasing an even greater amount of energy. A Neutron bomb for example replaces some/all of the 238 with lead, so the neutrons escape without causing more fision. Again, this is all speculation from scientists outside the various labs, and using publicly available information. For power generation, since the energy from any fusion reaction is primarily emitted as heat and neutrons. The neutrons are difficult to utilize and is basically wasted energy, but the heat would just heat water, turning it into steam, then turning a turbine.

by teach 4y ago

JumpCrisscross 4y ago

> "ignition" means that you get more energy out than the lasers impart. This is the first time anyone has pulled that off in decades of trying, which is a big deal. The term is refreshingly intuitive. For decades we've been striking stone and flint. Sparks. We just got a bit of kindling going. It's no bonfire. But it's a big step forward.

WithinReason 4y ago

>This is the first time anyone has pulled that off in decades of trying, which is a big deal. Are you sure of that? This is from 2014: https://arstechnica.com/science/2014/02/giant-leap-for-nuclear-fusion-as-scientists-get-more-energy-out-than-fuel-put-in/?itm_source=parsely-api https://arstechnica.com/science/2014/02/giant-leap-for-nucle...

falcor84 4y ago
Quoting from the article you linked to: Hurricane’s current output, although more than the hydrogen fuel put into the reaction, hasn’t yet reached the stated goal to achieve “ignition," where nuclear fusion generates as much energy as the lasers supply. At that point it might be possible to make a sustainable power plant based on the technology.
tingletech 4y ago
from your article: > Hurricane’s current output, although more than the hydrogen fuel put into the reaction, hasn’t yet reached the stated goal to achieve “ignition," where nuclear fusion generates as much energy as the lasers supply.

darksaints 4y ago

How do fusion bombs achieve "ignition"? It's not with lasers, right? Also, couldn't the net energy from the ignition be used to continue the reaction, so you only need the lasers for startup? Sorry for the newb questions, just curious.

scarier 4y ago
With a fission bomb. Don’t have a good explanation for your second question, although I think the short answer is “not with the way the Livermore experiment was set up.”
jboy55 4y ago
Caveat: This comment is derived from publicly available info. An H-bomb is a two part bomb. The primary bomb is a implosion plutonium bomb similar in make to the nagasaki/trinity bomb. It is theorized the Xrays from that bomb are focused on a secondary cylinder of uranium-238 that has a core of hydrogen and/or lithium. The Xrays ablate this casing at such intensity that the inward force (the opposite force of the ablation) is strong enough to propell the casing inwards at 300 km/second. This squeezes the hydrogen/lithium and causes fusion which releases a tone of energy, but more importantly a huge amount of neutrons. These neutrons cause the 238 in the casing to fission releasing an even greater amount of energy. A Neutron bomb for example replaces some/all of the 238 with lead, so the neutrons escape without causing more fision. Again, this is all speculation from scientists outside the various labs, and using publicly available information. For power generation, since the energy from any fusion reaction is primarily emitted as heat and neutrons. The neutrons are difficult to utilize and is basically wasted energy, but the heat would just heat water, turning it into steam, then turning a turbine.