Mixture Amount History

During Run 50 we added 4He, bringing the mixture up to about 800 mbar. That was our first successful fridge run in PAN 43.

The mixture amount tends to fall slowly from run to run

After Run 46 we changed the oil in the 3He circulation pump. We seem to have lost some mixture in the process.

Starting with hints in Run 71 and more obviously in Runs 72&73, the base temperature seemed to exhibit a new sensitivity to transfers. One hypothesis is that the still level is low and that adding more 4He will help.

During Run 76, the mixture content was 708.6 mbar.

During Run 78, there was IGH issue which lead to complete change in the IGH system, the dump pressure was showing 650 mbar on the new gauge.

During Run 82, we added more mixture He3/He4, to bring it up to 700 mbar.