|
Back in the saddle again
Join Date: Oct 2001
Location: Central TX west of Houston
Posts: 56,713
|
Quote:
Originally Posted by Don Plumley
They are on because they are perpetual motion machines. Modern MRI's use superconducting wire for the primary magnet. At 4K, the wire has zero resistance to electricity. So once the coil is cooled to 4K with liquid He, the coil is energized and then the source of electricity is removed. As long as the coil stays cold, the magnetic field remains. [BTW: I used to work for a division of Intermagnetics, which makes the coil for Philips MRI systems; and am also familiar with 2G wire which works at LN2 temps. I'm still blown away at the manufacturing prowess to make one of the 3T coils.]
Back to regularly scheduled randomness:
 |
The MRI would probably get that nail out in a hurry. Hopefully through the front and not the back or side.
__________________
Steve
'08 Boxster RS60 Spyder #0099/1960
- never named a car before, but this is Charlotte.
'88 targa  SOLD 2004 - gone but not forgotten
|