5 ms·

This is indeed very promising, but not necessarily a breakthrough yet. There's still the issue of operating temperature. The researcher said the next step is to

This is indeed very promising, but not necessarily a breakthrough yet. There's still the issue of operating temperature. The researcher said the next step is to try to get this to work with fancier superconductors that operate at 77K, which would "only" require liquid nitrogen cooling. If that is achieved, then I see this having real applications, but niche ones. More revolutionary applications would require room temperature, normal pressure superconductors, which AFAIK haven't yet been found, and might be possible at all(it's an open question). Even if they were found, there's of course also the question of whether the cost of those materials can be brought down enough to be worth the gains in efficiency etc.

dgoldstein0 4y ago
Yup. One thing I'm wondering: superconductors are supposed to be more efficient because they waste no power as heat. But doesn't it take power to maintain such cold temperatures, even for "high temperature" liquid nitrogen temperatures? How does this compare to the energy we save from the lack of resistance in the superconductor?
- AussieWog93 4y ago
  >But doesn't it take power to maintain such cold temperatures, even for "high temperature" liquid nitrogen temperatures? How does this compare to the energy we save from the lack of resistance in the superconductor? Not a thermals guy, but bog-standard, consumer air conditioners tend to have efficiencies of 300% or so. Ie, for every joule of electrical energy consumed, they'll reduce the thermal energy in the room by 3 joules. Regardless of this, having zero heat output in the wafer itself could be far more interesting than just increased power efficiency. For example, without the issue of thermals one could imagine silicon wafers with thousands of layers and 3-D interconnects.
- willis936 4y ago
  It depends on how much current you want. I worked on a 1.2 m major radius 1 T copper stellarator that used 10 MW of power for the confinement coils. The coils are water cooled but even then the shots are only 1-second to avoid overheating (and to save on the engineering cost of the power system). Any real fusion reactor would need 5+ T confinement fields and be 2+ times the radius of this machine. You would be using many GW in ohmic losses in copper confinement coils for hundreds of MW of fusion power: it simply could never work. A cryoplant for an LTS fusion reactor would use on the order of 50 MW, a bit less for HTS. So for the big magnet application superconductors are an incredible win.
- XorNot 4y ago
  It's a question of what you're spending power on. When you cool something there's the action of pumping heat away from it, and then the issue of how easily heat can migrate back in. So you're only really fighting the inefficiency of your insulation, and insulation can be very, very good (at the extreme end you could magnetically balance something in a vacuum chamber and then chill it - it'll take a very long time to heat up by radiative emission from the walls (double wall insulated cups use this property though my take is they're just gas filled - same idea though). Essentially the ongoing cost of keeping something cool is purely a function of heat load making it through insulation, and in all cases that's going to be much lower then generating heat in the system - the problem is that engineering and complexity wise, it's non-trivial and failure scenarios can be bad - i.e. an SC magnet quench can be very bad since you amongst other things might immediately boil your coolant. This happened at the LHC during commissioning.
pg_bot 4y ago
To be fair 'only' requiring liquid nitrogen is a much easier proposal than liquid helium as nitrogen can be sourced from air and is way less expensive.
justinclift 4y ago
At some point, I wonder if it'd just be cheaper and easier to put our supercomputers beneath the earth's crust. :) There's a billion $$$ startup idea. Let's get some people together to start serious superconductive computing below the Kola Superdeep Borehole: https://en.wikipedia.org/wiki/Kola_Superdeep_Borehole https://en.wikipedia.org/wiki/Kola_Superdeep_Borehole Well, apart from the Russian-Ukrainian war going on presently. :( So plan B, need to put a superdeep borehole somewhere else. Maybe at the KTB borehole in Bavaria? https://en.wikipedia.org/wiki/German_Continental_Deep_Drilling_Programme https://en.wikipedia.org/wiki/German_Continental_Deep_Drilli...
- bad_alloc 4y ago
  How would that help? Temperature goes up as you go down.
  - Enginerrrd 4y ago
    Exactly. Now a massive computing center in Antarctica however might have some merits.
    - Maursault 4y ago
      Not if Climate Change is any concern. What we need in Antarctica is a factory that makes it colder there, not dump heat there. What you want to do is have heatsinks that dump heat to the cold side of the vacuum of space.
      - Enginerrrd 4y ago
        This is... kind of delusional.
        Maursault 4y ago
        Crazy or not, all that matters is whether it's profitable.
  - 4y ago

dgoldstein0 4y ago

Yup. One thing I'm wondering: superconductors are supposed to be more efficient because they waste no power as heat. But doesn't it take power to maintain such cold temperatures, even for "high temperature" liquid nitrogen temperatures? How does this compare to the energy we save from the lack of resistance in the superconductor?

AussieWog93 4y ago
>But doesn't it take power to maintain such cold temperatures, even for "high temperature" liquid nitrogen temperatures? How does this compare to the energy we save from the lack of resistance in the superconductor? Not a thermals guy, but bog-standard, consumer air conditioners tend to have efficiencies of 300% or so. Ie, for every joule of electrical energy consumed, they'll reduce the thermal energy in the room by 3 joules. Regardless of this, having zero heat output in the wafer itself could be far more interesting than just increased power efficiency. For example, without the issue of thermals one could imagine silicon wafers with thousands of layers and 3-D interconnects.
willis936 4y ago
It depends on how much current you want. I worked on a 1.2 m major radius 1 T copper stellarator that used 10 MW of power for the confinement coils. The coils are water cooled but even then the shots are only 1-second to avoid overheating (and to save on the engineering cost of the power system). Any real fusion reactor would need 5+ T confinement fields and be 2+ times the radius of this machine. You would be using many GW in ohmic losses in copper confinement coils for hundreds of MW of fusion power: it simply could never work. A cryoplant for an LTS fusion reactor would use on the order of 50 MW, a bit less for HTS. So for the big magnet application superconductors are an incredible win.
XorNot 4y ago
It's a question of what you're spending power on. When you cool something there's the action of pumping heat away from it, and then the issue of how easily heat can migrate back in. So you're only really fighting the inefficiency of your insulation, and insulation can be very, very good (at the extreme end you could magnetically balance something in a vacuum chamber and then chill it - it'll take a very long time to heat up by radiative emission from the walls (double wall insulated cups use this property though my take is they're just gas filled - same idea though). Essentially the ongoing cost of keeping something cool is purely a function of heat load making it through insulation, and in all cases that's going to be much lower then generating heat in the system - the problem is that engineering and complexity wise, it's non-trivial and failure scenarios can be bad - i.e. an SC magnet quench can be very bad since you amongst other things might immediately boil your coolant. This happened at the LHC during commissioning.

pg_bot 4y ago

To be fair 'only' requiring liquid nitrogen is a much easier proposal than liquid helium as nitrogen can be sourced from air and is way less expensive.

justinclift 4y ago

At some point, I wonder if it'd just be cheaper and easier to put our supercomputers beneath the earth's crust. :) There's a billion $$$ startup idea. Let's get some people together to start serious superconductive computing below the Kola Superdeep Borehole: https://en.wikipedia.org/wiki/Kola_Superdeep_Borehole https://en.wikipedia.org/wiki/Kola_Superdeep_Borehole Well, apart from the Russian-Ukrainian war going on presently. :( So plan B, need to put a superdeep borehole somewhere else. Maybe at the KTB borehole in Bavaria? https://en.wikipedia.org/wiki/German_Continental_Deep_Drilling_Programme https://en.wikipedia.org/wiki/German_Continental_Deep_Drilli...

bad_alloc 4y ago
How would that help? Temperature goes up as you go down.
- Enginerrrd 4y ago
  Exactly. Now a massive computing center in Antarctica however might have some merits.
  - Maursault 4y ago
    Not if Climate Change is any concern. What we need in Antarctica is a factory that makes it colder there, not dump heat there. What you want to do is have heatsinks that dump heat to the cold side of the vacuum of space.
    - Enginerrrd 4y ago
      This is... kind of delusional.
      - Maursault 4y ago
        Crazy or not, all that matters is whether it's profitable.
- 4y ago