[MrWookie]

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If you do it right, you don't even need a quake to see cool things with liquid helium. It'll crawl up the sides of the container it's sitting in and run down the sides as if it was defying gravity if you do it right.

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Yea, helium is funky. In NMR machines its used to cool the magnet because one needs a superconducting magnet to reach the fields for high-field NMR. The helium chamber is in turn surrounded by a chamber containing liquid nitrogen to keep it from evaporating to fast. So when one of them falls over there will be like 100l+ of liquid gas reaching room temperature in a few seconds in a formally closed vessel -> boom -> Xylocain gets frozen to -78 and suffocates -> No more spewmonkey at PS 0.5/1

The gases obv have to be 'open' to air in normal operation because liquid helium is only -270 at atomsphere pressure. If I pop down there and put a stopper in each machine we will need a new NMR facility tomorrow LDO [img]/images/graemlins/laugh.gif[/img]

BTW In very advanced machines >800 MHz one actually uses small pumps to drive off helium to cool the magnet even further. -> more mobnies faster!

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I guess in all the superconducting magnet systems I've worked with, they've had the helium compressor siphoning off the gaseous He and recondensing it. Considering the cost of liquid helium, it seems that the compressor pays for itself many times over in not much time.