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Long Island man wearing 9kg-metal necklace dies after being sucked into MRI machine (www.independent.co.uk)
submitted 1 year ago by to c/nottheonion@lemmy.world
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[–] 15 points 1 year ago (3 children)

Depends on the machine type. Closed bore machines (the vast majority) use supercunducting electromagnets that are surrounded by liquid helium that creates a very strong magnetic field. To demagnetize them requires dumping the helium.

Some open bore machines use electromagnets, but they're much less common and not as powerful.

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  • [–] 1 point 1 year ago (2 children)

    So the helium itself becomes magnetized, is that it?

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  • [–] 19 points 1 year ago

    the helium is liquid, which it only is when it is very very cold.
    The superconductor will keep it's magnetic field forever, as long as it's superconducting, and it will stay superconducting while it is very very cold.

    There is physically no way (as in, it is simply impossible, due to how our world works, not money, not people, not technology) to instantly "switch off" the magnet.

    it needs to go above a certain temperature, to lose it's superconducting nature, and it needs to do it at a pace that doesn't dump a GINORMOUS amount of energy in this magnetic field instantly, because that would be even worse.

    the fault here is in allowing anyone with any magnetic metal anywhere near an MRI. And whoever let that happen is going to have a very bad week.

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