quenching
Quenching refers to rapid expulsion of the liquid cryogen used to maintain the MRI magnet in a superconducting state.
Discussion
Modern MRI scanners contain superconducting magnets which have very low energy consumption, made possible by maintaining internal subzero temperatures by way of a 'cryogen bath' of liquid helium. In the event that somebody pushes the emergency stop button or there is an equipment fault, the liquid helium boils off rapidly accompanied by a loud banging or hissing sound, safely expelled from the building by means of a dedicated venting system.
Hazards
Extremely rare but if for some reason the gas should escape into the room instead of being vented outside the building, there is a risk of asphyxiation and frostbite.
Siehe auch:
