14 ms·

Can someone with more knowledge talk a bit about the most immediate and practical uses of a room temperature semi conductor? From what I understand, non-chemica

Can someone with more knowledge talk a bit about the most immediate and practical uses of a room temperature semi conductor? From what I understand, non-chemical batteries (ie: current-trapped-forever-in-a-rock), hand held MRI machines, passively levitating trains, and dramatically simpler nuclear reactors are on the table. However, the articles I can grok don’t exactly give a hint as to how far A is from B - ie: does a room temp super conductor solve for 5% or 95% of these challenges? I’ve never been filled with regret for not going to college. I did extremely well for myself and my family by avoiding it, despite my desire and my love for learning. But reading this… I’m very jealous of you physicists!

wolfram74 3y ago
Of that particular list, I would say levitating trains are currently solved from a technical view point[0], and are awaiting economic viability. I know enough about fusion to say while having stronger magnetic fields make things easier, there's a lot of plasma physics that needs to be understood to do confinement. Furthermore the easy reactions all have neutron radiation to deal with so it is an open question if it will avoid all the same social problems fission has had piled on it. Hand held MRIs... that's a stretch, you can make better detectors with SCs, but even so, I suspect you'll want to wrap the area of interest in some apparatus. One you didn't mention and I had been somewhat dismissing until last week was energy storage, we have big existing ones already[1] and several of their drawbacks go away if their refrigeration demands drop to 0. [0]https://www.youtube.com/watch?v=4ZX9T0kWb4Y https://www.youtube.com/watch?v=4ZX9T0kWb4Y [1]
- midoridensha 3y ago
  >Of that particular list, I would say levitating trains are currently solved from a technical view point[0], and are awaiting economic viability. No, they're not. They're already economically viable: that's why Japan is building one between Tokyo and Nagoya right now, and it'll be in service later this decade. The current bullet trains are huge money-makers and have been for a long time; the Chuo shinkansen will be too.
  - raincole 3y ago
    China's Maglev keeps losing money. Something is built and in service == economically viable in decision-makers(often politicians!)' minds != economically viable.
    - midoridensha 3y ago
      China's "maglev" is a short train to the airport. It's for demonstration purposes only. Japan's maglev is connecting the largest city in the world with one of its other largest cities. When complete, it'll connect the 3 largest metro areas in the country together. Japan already has a bullet train that does exactly this, and it makes tons of money, and it's been doing so since the 1960s.
      - ororroro 3y ago
        Japan's commercial maglev is not yet completed. All current Japanese high speed services are conventional rail. There is a small test track for maglev and an under-construction commercial maglev with no public completion date (https://en.wikipedia.org/wiki/Ch%C5%AB%C5%8D_Shinkansen https://en.wikipedia.org/wiki/Ch%C5%AB%C5%8D_Shinkansen).
        midoridensha 3y ago
        >with no public completion date Wrong, the first leg will be complete in 2027. It takes some time because 90% of it is underground. Yes, it's not completed yet, but it doesn't matter: it's virtually guaranteed to be profitable, just because the current shinkansen are.
  - iraqmtpizza 3y ago
    Japan doesn't subsidize their maglev trains at all?
    - deleted 3y ago
      [deleted]
whatshisface 3y ago
Circular particle accelerators like the LHC, fusion reactors and quantum computers all obtain a large part of their complexity and expense from the cryogenic refrigerators that are necessary for them to work. It goes unnoticed because people think of it as a "solved problem," but keeping tons of material at liquid nitrogen temperatures takes a lot of energy and huge apparatuses.
- kadoban 3y ago
  That's not to mention delays in work too. Every time there's a "quenching" event at the LHC, that's days/weeks/months fixing everything and getting it back down to temp. I seem to recall they had to shut down for a year or so for upgrades at one point too. Having to work around the cooling had to have affected that timeline.
- fnands 3y ago
  > material at liquid nitrogen temperatures Even worse sometimes. For the LHC it's liquid helium temperatures!
- klyrs 3y ago
  As I understand it (not an expert) superconducting qubits are strongly impacted by temperature. So they're typically operated at sub-Kelvin temperatures, using liquid helium. Worse yet, they need unobtanium: helium 3. https://en.m.wikipedia.org/wiki/Dilution_refrigerator https://en.m.wikipedia.org/wiki/Dilution_refrigerator
alsaaro 3y ago
https://threadreaderapp.com/thread/1685088625187495936.html https://threadreaderapp.com/thread/1685088625187495936.html The most immediate and interesting are improvements to generators (35%) and SQUIDS.
DoingIsLearning 3y ago
Superconductor though. A semiconductor is a material that is somewhere in between conductor and insulator and varies depending on things like temperature or current direction. That is the material used in transistors and diodes. I would say we are very far away even if this proves to be it. First you would need to manufacture it reliably, then reliably without impurities, then reliably in some constrained 2d/3d geometry. Then you can start thinking about small footprint applications like IC design (chips and sensors). Perhaps then scale it to PCB design and RF applications like coplanar waveguides. With that alone you would enter a new era in electronics with virtually no 'thermal noise' and no residual heat. Beyond that (think large coils, motors, electromagnets) you would need a very large design step. As far as I understand this is still a very brittle ceramic, manufacturing very large or very long chains of this material would be unlikely. So the floating trains are probably a bit further away into the future.
- NoMoreNicksLeft 3y ago
  Supposing this lead apatite if conducive, can we not use it for high voltage cables? Some absurd level of energy loss occurs in those. I understand that there are current limitations inherent in superconductors, but is there no way to scale this?
  - klodolph 3y ago
    The cost of losses in the cables may be high, but the cost of superconducting cables may be much higher. Superconductors may be fragile and unsuitable for cables.
  - arcticbull 3y ago
    > Some absurd level of energy loss occurs in those. It doesn't really - because we do the transmission at very high voltage, and the power loss is proportional to 1/V. Power loss in transmission in the US is about 5%. In the transmission lines themselves it's only 2-4%. [1] If you ran a power line all the way across the entire continental United States, you'd still get about 80% of the power out of the other end. The longest economically effective distance you can run an AC power line is about 2500mi, and DC around 4300mi. [2] [1] https://chintglobal.com/blog/how-much-power-loss-in-transmission-lines/ https://chintglobal.com/blog/how-much-power-loss-in-transmis... [2] https://en.wikipedia.org/wiki/Electric_power_transmission#cite_note-limits-of-very-long-distance-22 https://en.wikipedia.org/wiki/Electric_power_transmission#ci...
Out_of_Characte 3y ago
Immediate applications for a rtsc would be MRI machines. Those cost between 300k and 500k. They require helium for operation. A superconductor at room temparature could remove the need for helium or even nitrogen. It could possibly make the machine work with a thermal electric cooler which would drastically lower the upfront cost and the maintenance cost of an MRI. Also, the machine would become smaller which would eliminate the need to roll patients into the machine itself, further reducing costs. Where a big hospital could only afford one MRI, many small hospitals can now potentially get one for 80k. I dont know any other existing commercial applications of superconductors.

wolfram74 3y ago

Of that particular list, I would say levitating trains are currently solved from a technical view point[0], and are awaiting economic viability. I know enough about fusion to say while having stronger magnetic fields make things easier, there's a lot of plasma physics that needs to be understood to do confinement. Furthermore the easy reactions all have neutron radiation to deal with so it is an open question if it will avoid all the same social problems fission has had piled on it. Hand held MRIs... that's a stretch, you can make better detectors with SCs, but even so, I suspect you'll want to wrap the area of interest in some apparatus. One you didn't mention and I had been somewhat dismissing until last week was energy storage, we have big existing ones already[1] and several of their drawbacks go away if their refrigeration demands drop to 0. [0]https://www.youtube.com/watch?v=4ZX9T0kWb4Y https://www.youtube.com/watch?v=4ZX9T0kWb4Y [1]

midoridensha 3y ago
>Of that particular list, I would say levitating trains are currently solved from a technical view point[0], and are awaiting economic viability. No, they're not. They're already economically viable: that's why Japan is building one between Tokyo and Nagoya right now, and it'll be in service later this decade. The current bullet trains are huge money-makers and have been for a long time; the Chuo shinkansen will be too.
- raincole 3y ago
  China's Maglev keeps losing money. Something is built and in service == economically viable in decision-makers(often politicians!)' minds != economically viable.
  - midoridensha 3y ago
    China's "maglev" is a short train to the airport. It's for demonstration purposes only. Japan's maglev is connecting the largest city in the world with one of its other largest cities. When complete, it'll connect the 3 largest metro areas in the country together. Japan already has a bullet train that does exactly this, and it makes tons of money, and it's been doing so since the 1960s.
    - ororroro 3y ago
      Japan's commercial maglev is not yet completed. All current Japanese high speed services are conventional rail. There is a small test track for maglev and an under-construction commercial maglev with no public completion date (https://en.wikipedia.org/wiki/Ch%C5%AB%C5%8D_Shinkansen https://en.wikipedia.org/wiki/Ch%C5%AB%C5%8D_Shinkansen).
      - midoridensha 3y ago
        >with no public completion date Wrong, the first leg will be complete in 2027. It takes some time because 90% of it is underground. Yes, it's not completed yet, but it doesn't matter: it's virtually guaranteed to be profitable, just because the current shinkansen are.
- iraqmtpizza 3y ago
  Japan doesn't subsidize their maglev trains at all?
  - deleted 3y ago
    [deleted]

whatshisface 3y ago

Circular particle accelerators like the LHC, fusion reactors and quantum computers all obtain a large part of their complexity and expense from the cryogenic refrigerators that are necessary for them to work. It goes unnoticed because people think of it as a "solved problem," but keeping tons of material at liquid nitrogen temperatures takes a lot of energy and huge apparatuses.

kadoban 3y ago
That's not to mention delays in work too. Every time there's a "quenching" event at the LHC, that's days/weeks/months fixing everything and getting it back down to temp. I seem to recall they had to shut down for a year or so for upgrades at one point too. Having to work around the cooling had to have affected that timeline.
fnands 3y ago
> material at liquid nitrogen temperatures Even worse sometimes. For the LHC it's liquid helium temperatures!
klyrs 3y ago
As I understand it (not an expert) superconducting qubits are strongly impacted by temperature. So they're typically operated at sub-Kelvin temperatures, using liquid helium. Worse yet, they need unobtanium: helium 3. https://en.m.wikipedia.org/wiki/Dilution_refrigerator https://en.m.wikipedia.org/wiki/Dilution_refrigerator

alsaaro 3y ago

https://threadreaderapp.com/thread/1685088625187495936.html https://threadreaderapp.com/thread/1685088625187495936.html The most immediate and interesting are improvements to generators (35%) and SQUIDS.

DoingIsLearning 3y ago

Superconductor though. A semiconductor is a material that is somewhere in between conductor and insulator and varies depending on things like temperature or current direction. That is the material used in transistors and diodes. I would say we are very far away even if this proves to be it. First you would need to manufacture it reliably, then reliably without impurities, then reliably in some constrained 2d/3d geometry. Then you can start thinking about small footprint applications like IC design (chips and sensors). Perhaps then scale it to PCB design and RF applications like coplanar waveguides. With that alone you would enter a new era in electronics with virtually no 'thermal noise' and no residual heat. Beyond that (think large coils, motors, electromagnets) you would need a very large design step. As far as I understand this is still a very brittle ceramic, manufacturing very large or very long chains of this material would be unlikely. So the floating trains are probably a bit further away into the future.

NoMoreNicksLeft 3y ago
Supposing this lead apatite if conducive, can we not use it for high voltage cables? Some absurd level of energy loss occurs in those. I understand that there are current limitations inherent in superconductors, but is there no way to scale this?
- klodolph 3y ago
  The cost of losses in the cables may be high, but the cost of superconducting cables may be much higher. Superconductors may be fragile and unsuitable for cables.
- arcticbull 3y ago
  > Some absurd level of energy loss occurs in those. It doesn't really - because we do the transmission at very high voltage, and the power loss is proportional to 1/V. Power loss in transmission in the US is about 5%. In the transmission lines themselves it's only 2-4%. [1] If you ran a power line all the way across the entire continental United States, you'd still get about 80% of the power out of the other end. The longest economically effective distance you can run an AC power line is about 2500mi, and DC around 4300mi. [2] [1] https://chintglobal.com/blog/how-much-power-loss-in-transmission-lines/ https://chintglobal.com/blog/how-much-power-loss-in-transmis... [2] https://en.wikipedia.org/wiki/Electric_power_transmission#cite_note-limits-of-very-long-distance-22 https://en.wikipedia.org/wiki/Electric_power_transmission#ci...

Out_of_Characte 3y ago

Immediate applications for a rtsc would be MRI machines. Those cost between 300k and 500k. They require helium for operation. A superconductor at room temparature could remove the need for helium or even nitrogen. It could possibly make the machine work with a thermal electric cooler which would drastically lower the upfront cost and the maintenance cost of an MRI. Also, the machine would become smaller which would eliminate the need to roll patients into the machine itself, further reducing costs. Where a big hospital could only afford one MRI, many small hospitals can now potentially get one for 80k. I dont know any other existing commercial applications of superconductors.