Oxford Instruments 18T magnet

Having turned off the compressor, the magnet will slowly warm up over a few weeks.
After prolonged operation, the magnet may contain some water that has consed inside. Close the main He return valve on the magnet and also the valve connecting the magnet to the LN2 cold trap.
Open the magnet lid. To remove water, get a long stick and attach some tissue paper or towel. Be sure that you don't lose this in the magnet! Soak up all the water.
Pump the outer vacuum shield of the magnet. Use the turbo pump (be sure to pump out the tube connecting the pump to the valve on the magnet). Leave to pump for about a day until the pressure is around 10-5 mbar.
Connect a compressed He gas bottle (or He dewar) and a rotary pump to the line connected to the main He return valve on the 18T magnet.
Pump and flush several times. Pump for about 30-60 min.
Remove the pump but leave the He gas line connected.
Set up the gas bottle and/or dewar so the pressure on the digital pressure guage is around 40 mbar. If it's higher, you'll just be venting He gas into the return line, if it's too low, the compressor will not be working efficiently.
Turn on the compressor (in the basement)
The temperature of the magnet can be read by measuring the resistance of the superconducting coils. At room temperature the resistance is 95 Ohm and 0.1 Ohm at 4.2 K.
During cool down on 17.01.2018, it took 5 days of running to go from room temperature to 4.2 K.

A pdf manual on how to clean the nitrogen trap can be found here : https://wiki.epfl.ch/lqm/documents/nitrogen_trap_cleaning.pdf

In case the nitrogen dewar needs filling, one can refill it by steps described in the manul : https://wiki.epfl.ch/lqm/documents/nitrogen_dewar_filling_.pdf