LN2 is not enough you need LHe for most superconductors. It is usually cooled by LHe that is itself shieled by LN2 to limit losses. LN2 is relatively cheap not

LN2 is not enough you need LHe for most superconductors. It is usually cooled by LHe that is itself shieled by LN2 to limit losses. LN2 is relatively cheap not LHe. That's why there are recylcing systems to recover the boiling off He in MRIs, NMRs and other supraconducting systems. There are systems that allow cooling without wasting LHe/LN2 but they are pretty limited in size or costly: https://hexus.net/tech/news/cooling/131414-worlds-first-absolute-zero-magnetic-cooler-developed/ https://hexus.net/tech/news/cooling/131414-worlds-first-abso... https://www.wired.co.uk/article/mri-magnet-cooling https://www.wired.co.uk/article/mri-magnet-cooling https://en.wikipedia.org/wiki/Dilution_refrigerator https://en.wikipedia.org/wiki/Dilution_refrigerator edit: s/LH2/LHe