A magnet quench, I mean a superconducting magnet quench (we do not give a shite about that silly room temp. stuff) is an avalanche process which starts with the superconducting coil jumping its critical temperature. At which it becomes resistive. Hence dissipating heat. Hence heating its liquid helium sheath. Hence becoming more resistive. Hence heating further. This is an avalanche process which culminates in the coil reaching room temperature and the helium boiling off. NMR rooms usually have helium vent lines in case of such quenches. Otherwise any occupants in the room would probably asphyxiate. This is a cool viddy of such a quench under controlled conditions. Magnets can be recovered after a quench, but it is a time consuming and expensive process (especially in the liquid helium it takes to cool the coils down again). Apparently this has happened at CERN. And they have hundreds of such magnets!
No comments:
Post a Comment