5 ms·

>Their most recent article has a ton of great data and next steps: That device in the photo is great. Looks to be about 16AWG magnet wire. Guessing a 10mm ID

by floxy 4y ago

>Their most recent article has a ton of great data and next steps: That device in the photo is great. Looks to be about 16AWG magnet wire. Guessing a 10mm ID of the coil, and about 25mm in length. To get to 26 Tesla, looks like you'd need to push about 33,000 A through that coil. Coil inductance might be about 1uH, and if the test lasts ~1us, then you'd need 33kV to push that 33kA through the coil. 30kV/inch insulation resistance, might not get arcing between the wires in air. Probably running the thing in vacuum? Looks like things check out. https://www.eeweb.com/tools/magnetic-field-calculator/ https://www.eeweb.com/tools/magnetic-field-calculator/ >NIF has uncovered some new science What is the new science? Seems like they are working on making the fuel pellets closer to perfect, which makes sense if you are trying to use the implosion shock wave inside the fuel to be the source of heat and pressure needed for further fusion. I'm imagining that the laser initiates the surface fusion, and then you want that fusion to propagate inward, and need thing perfect, so the fuel doesn't go squirting out the sides (so to speak) stopping the chain reaction.

donquixote25 4y ago
Yea, the whole target bay is in vacuum which helps with the arcing.
- moloch-hai 4y ago
  Vacuum is supposed to increase arcing. People who want to prevent arcing flood the cavity with sulfur hexafluoride. Fun fact, it has 25,000 times the "greenhouse potential" of CO2. Dunno if that includes lifetime in the atmosphere, or just instantaneous opacity to IR. All the wind turbines are pumped full of it. There is an effort on to switch to something else of proprietary composition.
  - donquixote25 4y ago
    That is only true to a certain point. Look up Paschen's law. After you go lower than a certain point, around 10 Torr cm depending on the gas, decreasing pressure increases the breakdown voltage. It's probably not feasible to pump to such low pressures in wind turbines, so they probably don't even try. But for NIF, it's common.
  - Gud 4y ago
    I don’t know about the actual turbines, but there is GIS switchgear and it’s sealed. Modern GIS don’t leak much(extremely little).
  - liketochill 4y ago
    A breaker can use sf6 gas but usually that is at 60 kV and above. For 35 kV and below vacuum bottle breakers are much cheaper than sf6. individual wind turbines are not generating at more than 13.8kV so I would be surprised if they had any sf6 in them.
  - mavhc 4y ago
    They're not pumped full of it though, are they. "Data from Vattenfall suggests leakage emissions from Europe’s 100,000 wind turbines were about 900kg of SF6 over the last six years. This is equivalent to 3,525 tonnes of CO2 a year. This includes the release of gases during the reclamation and recycling process. At end-of-life the turbine switchgears are collected and the sulphur hexafluoride gas is reclaimed and reused in new equipment. By comparison wind energy avoids the emission of 255 million tonnes of CO2 in Europe a year by generating 336TWh of electricity displacing fossil fuels. The SF6 leakage therefore represents around 0.001% of the emissions avoided thanks to wind energy every year."
  - savingsPossible 4y ago
    Sorry, this is just FUD. Provide links? Also, 25000 times might be ok, if the amount of gas released in the atmosphere is 1/10^6, say, of the amount of co2
    - boringg 4y ago
      SF6 is 23,900 CO2e.
jkelleyrtp 4y ago
Before ignition, very little science had been explored in the "burning plasma" regime. Now that ignition had been figured out, an entire new field of experimentation has been opened up. https://www.llnl.gov/news/three-peer-reviewed-papers-highlight-scientific-results-national-ignition-facility-record https://www.llnl.gov/news/three-peer-reviewed-papers-highlig... In particular, the original article talks about magnetic compression hypothesis being a byproduct of white dwarf simulation. With this new regime, they were able to apply the same ideas to fusion, resulting in the breakthrough. With ignition being a regular thing in laser fusion going forward, I suspect many groups will have some slightly varied approach or some technique improvements. If you're into fusion and lasers, there's a lot of areas that are still ripe for magnitude leaps. - Laser power, timing, materials, and cost - Metallurgy of the target canister - Construction of the target and perfecting it as you mentioned - Absorption of energy I believe the NIF will focus on #2 and #3 as of course they focus more on making the "boom bigger" rather than making it cost effective of useful. IMO another group (startup or otherwise) will step in as an actual project in this space. One area to innovate here is to use a different fuel mixture that doesn't produce neutrons. We wouldn't need liquid lithium/lead, breeding, or any of the complexities people very commonly complain about. - https://en.wikipedia.org/wiki/Aneutronic_fusion https://en.wikipedia.org/wiki/Aneutronic_fusion - https://en.wikipedia.org/wiki/Direct_energy_conversion https://en.wikipedia.org/wiki/Direct_energy_conversion It's entirely within the realm of possibility that the technique to achieve ignition will open the door for 5:1 or 10:1 q with neutron-free fuels. Even a total Q of 2:1 or 3:1 is a huge win, and that's within a magnitude of the modern tech. -- Something I want to mention here too - the easiest aneutronic fuel mixture available is H2 + He3. It hasn't been explored too much since He3 is hard to come by on earth (though you can mine it from the moon!). But, Helion has patented a way to generate He3 from H2 fusions. We don't need to mine He3 to achieve neutron-free fuels, just need to transmute it from seawater.
- jnwatson 4y ago
  "magnetic compression hypothesis being a byproduct of white dwarf simulation" That is the coolest thing I'll read all month.
  - 4y ago
hawtkey 4y ago
here's a video that shows a machine at Berkeley lab that makes a high-performance magnet wire, not sure if it's related to this project but still pretty interesting to see how complex just the wire is- https://www.youtube.com/watch?v=FmmNRaKpBTI&t=2138s https://www.youtube.com/watch?v=FmmNRaKpBTI&t=2138s
- dmix 4y ago
  "It looks a bit Rube Goldberg esque coming out the back" Yes it does indeed. Amazing amount of trial and error to build such a machine.
  - apocalypstyx 4y ago
    Well, Goldberg was an engineer and supposedly did construct his drawings to be 'technically' feasible.
- artifact_44 4y ago
limaoscarjuliet 4y ago
Ironically vacuum, unless super perfect, is not that good insulator. All hvac techs who started compressor on vacuum (albeit much less perfect) can tell :)

by floxy 4y ago

donquixote25 4y ago

Yea, the whole target bay is in vacuum which helps with the arcing.

moloch-hai 4y ago
Vacuum is supposed to increase arcing. People who want to prevent arcing flood the cavity with sulfur hexafluoride. Fun fact, it has 25,000 times the "greenhouse potential" of CO2. Dunno if that includes lifetime in the atmosphere, or just instantaneous opacity to IR. All the wind turbines are pumped full of it. There is an effort on to switch to something else of proprietary composition.
- donquixote25 4y ago
  That is only true to a certain point. Look up Paschen's law. After you go lower than a certain point, around 10 Torr cm depending on the gas, decreasing pressure increases the breakdown voltage. It's probably not feasible to pump to such low pressures in wind turbines, so they probably don't even try. But for NIF, it's common.
- Gud 4y ago
  I don’t know about the actual turbines, but there is GIS switchgear and it’s sealed. Modern GIS don’t leak much(extremely little).
- liketochill 4y ago
  A breaker can use sf6 gas but usually that is at 60 kV and above. For 35 kV and below vacuum bottle breakers are much cheaper than sf6. individual wind turbines are not generating at more than 13.8kV so I would be surprised if they had any sf6 in them.
- mavhc 4y ago
  They're not pumped full of it though, are they. "Data from Vattenfall suggests leakage emissions from Europe’s 100,000 wind turbines were about 900kg of SF6 over the last six years. This is equivalent to 3,525 tonnes of CO2 a year. This includes the release of gases during the reclamation and recycling process. At end-of-life the turbine switchgears are collected and the sulphur hexafluoride gas is reclaimed and reused in new equipment. By comparison wind energy avoids the emission of 255 million tonnes of CO2 in Europe a year by generating 336TWh of electricity displacing fossil fuels. The SF6 leakage therefore represents around 0.001% of the emissions avoided thanks to wind energy every year."
- savingsPossible 4y ago
  Sorry, this is just FUD. Provide links? Also, 25000 times might be ok, if the amount of gas released in the atmosphere is 1/10^6, say, of the amount of co2
  - boringg 4y ago
    SF6 is 23,900 CO2e.

jkelleyrtp 4y ago

Before ignition, very little science had been explored in the "burning plasma" regime. Now that ignition had been figured out, an entire new field of experimentation has been opened up. https://www.llnl.gov/news/three-peer-reviewed-papers-highlight-scientific-results-national-ignition-facility-record https://www.llnl.gov/news/three-peer-reviewed-papers-highlig... In particular, the original article talks about magnetic compression hypothesis being a byproduct of white dwarf simulation. With this new regime, they were able to apply the same ideas to fusion, resulting in the breakthrough. With ignition being a regular thing in laser fusion going forward, I suspect many groups will have some slightly varied approach or some technique improvements. If you're into fusion and lasers, there's a lot of areas that are still ripe for magnitude leaps. - Laser power, timing, materials, and cost - Metallurgy of the target canister - Construction of the target and perfecting it as you mentioned - Absorption of energy I believe the NIF will focus on #2 and #3 as of course they focus more on making the "boom bigger" rather than making it cost effective of useful. IMO another group (startup or otherwise) will step in as an actual project in this space. One area to innovate here is to use a different fuel mixture that doesn't produce neutrons. We wouldn't need liquid lithium/lead, breeding, or any of the complexities people very commonly complain about. - https://en.wikipedia.org/wiki/Aneutronic_fusion https://en.wikipedia.org/wiki/Aneutronic_fusion - https://en.wikipedia.org/wiki/Direct_energy_conversion https://en.wikipedia.org/wiki/Direct_energy_conversion It's entirely within the realm of possibility that the technique to achieve ignition will open the door for 5:1 or 10:1 q with neutron-free fuels. Even a total Q of 2:1 or 3:1 is a huge win, and that's within a magnitude of the modern tech. -- Something I want to mention here too - the easiest aneutronic fuel mixture available is H2 + He3. It hasn't been explored too much since He3 is hard to come by on earth (though you can mine it from the moon!). But, Helion has patented a way to generate He3 from H2 fusions. We don't need to mine He3 to achieve neutron-free fuels, just need to transmute it from seawater.

jnwatson 4y ago
"magnetic compression hypothesis being a byproduct of white dwarf simulation" That is the coolest thing I'll read all month.
- 4y ago

hawtkey 4y ago

here's a video that shows a machine at Berkeley lab that makes a high-performance magnet wire, not sure if it's related to this project but still pretty interesting to see how complex just the wire is- https://www.youtube.com/watch?v=FmmNRaKpBTI&t=2138s https://www.youtube.com/watch?v=FmmNRaKpBTI&t=2138s

dmix 4y ago
"It looks a bit Rube Goldberg esque coming out the back" Yes it does indeed. Amazing amount of trial and error to build such a machine.
- apocalypstyx 4y ago
  Well, Goldberg was an engineer and supposedly did construct his drawings to be 'technically' feasible.
artifact_44 4y ago

limaoscarjuliet 4y ago

Ironically vacuum, unless super perfect, is not that good insulator. All hvac techs who started compressor on vacuum (albeit much less perfect) can tell :)