Question: What was biggest build you have ever done or doing?

Eleanor Holmes answered on 12 Nov 2013:

A few months ago our superconducting magnet was too hot. By too hot I mean it was at -267 degrees celsius instead of -269 C. One reason for this might be that there is a leak in the liquid helium line causing the cold, cold insides of the cryostat drum to become thermodynamically coupled to the room temperatures outside the drum. It was heating the whole thing up. So we had to take apart the whole cryostat to see if there were any leaks. It was a full two day job to pump out all the very expensive helium and unwrap all the layers of insulation inside to check for leaks in the pipes. Then put it all back together again and cool it down to test it.

I hope I never have to do all that again. Unfortunately our magnet is running a bit hot again… 🙁