2019/10/31 (Thursday)

Previous Day

	Status: At 77K discovered IVC leak near bottom of IVC. Warming now to check indium seal. Working toward 2nd attempt at Run 71 cooldown.
0800	MC(Cernox) = 230.4 K
0900	MC(Cernox) = 234.35 K the warming time constant (room temp = 296 K) appears to be 16.1 hours, which suggests MC will reach dew point (281 K) tomorrow 7:45 am.
0935	Check contents of warm LN2 Trap 2: 4.9 mbar. This was open to mixture during the LN2 transfer. Pump out trap with scroll pump.
0945	Start cryocleaning mixture through LN2 Cold Trap 1, V6 = 12.6%
0950	Increase V6 → 12.7% to restart flow
1000	Increase V6 → 12.8% to speed up flow
1000	MC(Cernox) = 238.05 K time constant ~ 16.2 hours, suggesting MC will reach dew point tomorrow 7:50 am.
1145	Increase V6 → 13.0% to restart flow
1100	MC(Cernox) = 241.5 K time constant ~ 16.3 hours, suggesting MC will reach dew point tomorrow 8:01 am.
1155	Increase V6 → 13.1% to speed up flow
1200	MC(Cernox) = 244.75 K time constant ~ 16.3 hours, suggesting MC will reach dew point tomorrow 7:58 am.
1240	Stop cleaning through Trap 1 after 175 min. G2 flow pressure was 560-750 mbar. Pump mixture to dump. Removed 3.8 mbar. That's a lot lower - maybe circulating during LN2 transfer did a lot of cleaning too, and maybe tightening the o-rings helped. Or maybe it's an anomaly.
1300	MC(Cernox) = 247.85 K time constant ~ 16.0 hours, suggesting MC will reach dew point tomorrow 7:41 am.
1400	MC(Cernox) = 247.85 K time constant ~ 16.1 hours, suggesting MC will reach dew point tomorrow 7:46 am.
1415	Check warm LN2 Cold Trap 1: 3.8 mbar. Pump out Trap 1.
1435	Start cryocleaning mixture through LN2 Cold Trap 1, V6 = 12.9%
1450	Increase V6 → 13.1% to restart flow
1455	Increase V6 → 13.2% to restart flow
1510	Increase V6 → 13.3% to speed up flow
1500	MC(Cernox) = 253.5 K time constant ~ 15.9 hours, suggesting MC will reach dew point tomorrow 7:36 am.
1535	Stop cleaning through Trap 1 after 60 min. G2 flow pressure was 570-980 mbar. Pump mixture to dump. Removed 5.6 mbar.
1705	Check warm LN2 Cold Trap 1: 5.6 mbar. Pump out Trap 1.

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