Fridges: first cooldown

The button has been pushed, and our two dilution fridges from Leiden Cryogenics are cooling down. Today they both reach 3 K and we start the condensation of He3/He4 mixture which is the first phase of the final cooldown to the base temperature of ~7 mK.

2013-05-19 12.24.45

You can also here the pulse tubes humming, though from where I sit in the meeting room I almost don’t hear them, just see the fridges through the glass window.