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====== Filling the N2 and He tanks ======

===== Liquid Nitrogen =====
To fill the nitrogen tank: \\

- connect a LN2 transfer tube to a LN2 storage dewer and insert the other end 40-50 cm deep inside the tank hole. \\
- pressurise the dewer till at least 500 mbar and slowly open the valve so that the liquid starts to flow. Then when the transfer tube is nicely solid and frozen, start to fill faster by opening the valve further.\\
- the tank is full when the LN2 overflows :-) Stop filling immediately. \\
- as soon as the the transfer tube is defrosted, remove it from the tank otherwise ice will block it inside.\\
- cover the hole of the tank with the chineese tea container :-) uspide down , otherwise ice will form inside the tank.

===== Liquid Helium =====
To fill the helium tank:\\

- switch on the level meter and if necessary the Kithley 199.\\
- keep the dewer open to the recovery line, by leaving the valve on the recovery panel open.\\
- open the dewer valve and SLOWLY lower the dewer side of the flexible transfer line inside the dewer.\\
- when the line touches the bottom, insert the cryostat side of the transfer line inside the cryostat (can be done fast).\\
- now lift a few centimeters the transfer line from the bottom of the dewer and fix it such that it won't slip down to the bottom again.\\
- now you can close the valve to the recovery line (on the panel) and start to pressurise the dewer: use ~100mbar at the beginning and when LHe transfer starts (i.e. when the gas-meter becomes less noisy and the termometers read 2.6 Ohm) pressurise up to 300mbar (max 500).\\
- you can read on the level meter the level: full = 544 mm \\
- when it's full, OPEN (slowly) THE VALVE TO RECOVERY.\\
- lift the transfer line at both the dewer and cryostat side and remove it.\\
- close the transfer hole :-) \\
- close the dewer :-) \\
- switch off the level meter!