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by reubens 2312 days ago
If I understand it correctly, the machine uses permanent magnets rather than a giant solenoid.

The magnetic field is way less strong (0.064 Tesla compared to at least 1 in most machines), but the machine doesn't have to generate heat while producing a magnetic field
1 comments
catblast 2312 days ago
An MRI magnet doesn’t produce heat while producing a magnetic field. That’s not why they are cooled. They are superconductors, the resistance is 0.
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duskwuff 2312 days ago
> They are superconductors, the resistance is 0.

So long as they stay under their critical temperature. If that changes… well, a lot of liquid helium is about to stop being liquid.

And that's one of the reasons why a permanent-magnet MRI is so interesting -- it doesn't depend on a constant supply of power (for the helium cooler) and gaseous helium (to replace lost gas), so the system is portable, and maintenance costs are likely to be much lower.

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