2019/05/07 (Tuesday)

Previous Day

Status	Room temperature, after second blockage. IVC and cryostat vacuum jacket pumped out. Several cleanings yesterday. Dump left open to cold LN2 Trap 2 overnight. Removed 6.0 mbar of contaminants from mixture overnight.
Setup	DIB1/3/4 → 3.2 MHz filters 2/3/1 → cable 3/1/2
0840	Fill LN2 cold trap bath
0845	Pump mixture from cold LN2 Trap 2 to dump.
0855	LN2 Trap 1 is warm. Check contents: 5.3-0.6 = 4.7 mbar on G1. Pump out with scroll pump.
0905	Start cryocleaning mixture through LN2 Cold Trap 1, V6 = 12.9%
0910	Increase V6 → 13.1% to restart flow
0915	Increase V6 → 13.2% to restart flow
0930	Increase V6 → 13.3% to speed up flow
1010	Stop cleaning through Trap 1 after 65 min. G2 flow pressure was 575-680 mbar. Pump mixture to dump. Removed 5.2 mbar.
1050	LN2 Trap 2 is warm. Check contents: 6.1-0.1 = 6.0 mbar on G1. Pump out with scroll pump.
1125	LN2 Trap 1 is mostly warm. Check contents: 5.2-0.0 = 5.2 mbar on G1. Pump out with scroll pump.
1140	Check fridge pressures: LHe trap/Condenser/Still = 0.3/0.2/0.018 mbar. Pump out with scroll pump.
1140	Open dump to both sides of fridge lines via LN2 cold trap 1.
1145	With 1K Pot speedivalve and needle valve closed, pump on Main bath with scroll pump. Once P2 < 100 mbar, open 1K pot speedivalve and needle valve (5 turns) to pump out 1K pot volume to < 1 mbar on P2.
1150	Close off scroll pump, then pressurized bath and 1K Pot (both sides) to (SKIP THIS PART: about 0.5 bar with helium. Then pump it out again with scroll pump to < 1 mbar.) Pressurize main bath and 1K Pot (both sides) to 377 mbar +1atm on G3, then close 1K Pot speedivalve and needle valve.
1150	Turbo on IVC = 7.4 nbar. With turbo valved out for a few minutes, IVC = 100 nbar.
1155	Let 5.4 mbar He exchange gas into IVC
1200	MC(Cernox) = 292.4 K, Sorb = >249 K (max), IVC = 5.4 mbar, G1 (fridge) = 618.2 mbar, Level resistor = 0.985 kΩ. DIB4 pD SQUID = 3.313 kΩ.
1200	Begin LN2 transfer
1215	MC(Cernox) = 292.3 K, Sorb = >249 K (max), IVC = 4.6 mbar, G1 (fridge) = 619.1 mbar, Level resistor = 0.990 kΩ. DIB4 pD SQUID = 3.286 kΩ.
1230	MC(Cernox) = 283.7 K, Sorb = >249 K (max), IVC = 4.0 mbar, G1 (fridge) = 619.4 mbar, Level resistor = 1.004 kΩ. DIB4 pD SQUID = 2.988 kΩ.
1245	MC(Cernox) = 261.5 K, Sorb = >249 K (max), IVC = 3.4 mbar, G1 (fridge) = 619.1 mbar, Level resistor = 1.014 kΩ. DIB4 pD SQUID = unstable at first, then 2.592 kΩ.
1300	MC(Cernox) = 241.9 K, Sorb = >249 K (max), IVC = 3.0 mbar, G1 (fridge) = 619.0 mbar, Level resistor = 1.028 kΩ. DIB4 pD SQUID = 2.29 kΩ.
1320	MC(Cernox) = 203.7 K, Sorb = >249 K (max), IVC = 2.5 mbar, G1 (fridge) = 618.4 mbar, Level resistor = 1.079 kΩ. DIB4 pD SQUID = 4.7 kΩ, unstable.
1330	MC(Cernox) = 184.7 K, Sorb = >249 K (max), IVC = 2.2 mbar, G1 (fridge) = 618.1 mbar, Level resistor = 1.114 kΩ. DIB4 pD SQUID = 1.807 kΩ.
1345	MC(Cernox) = 165.9 K, Sorb = >249 K (max), IVC = 2.2 mbar, G1 (fridge) = 617.5 mbar, Level resistor = 1.169 kΩ. DIB4 pD SQUID = 3 kΩ, unstable with Fluke; also unstable with Wavetek.
1400	MC(Cernox) = 145.9 K, Sorb = 242.7, IVC = 1.9 mbar, G1 (fridge) = 617.0 mbar, Level resistor = 1.232 kΩ. DIB4 pD SQUID = 1.665 kΩ.
1415	MC(Cernox) = 132.6 K, Sorb = 200.2, IVC = 1.9 mbar, G1 (fridge) = 616.1 mbar, Level resistor = 1.269 kΩ. DIB4 pD SQUID = 10 kΩ, unstable.
1430	MC(Cernox) = 120.3 K, Sorb = 165.3, IVC = 1.9 mbar, G1 (fridge) = 615.4 mbar, Level resistor = 1.296 kΩ. DIB4 pD SQUID = 8 kΩ, unstable.
1445	MC(Cernox) = 113.3 K, Sorb = 149.4, IVC = 1.6 mbar, G1 (fridge) = 615.4 mbar, Level resistor = 1.308 kΩ. DIB4 pD SQUID = 200 kΩ, unstable.
1450	Stop LN2 transfer. Put ping-pong ball cover on exhaust port.
1450	DIB4 pD SQUID = 1.86 kΩ, a little unstable.
1630	MC(Cernox) = 85.8 K, Sorb = 129.4, IVC = 1.6 mbar, G1 (fridge) = 616.4 mbar, Level resistor = 1.237 kΩ. DIB4 pD SQUID = 1.345 kΩ.

Leak detector test
1405	Set up leak detector with the forepump disconnected and capped. Hook the pump line to our scroll pump to pump with it instead. The P2 foreline pressure goes down to like 3e-2 mbar, much lower than the forepump seems to be capable of (3-12 mbar). Doing a test, the turbo pump is valved in right away.
1435	Doing a test on the blank - 1.5e-12 mbarL/s, super low. P2 = 4.0e-3 mbar (that's the test port pressure), P1 = 2.0e-2 mbar (that's the foreline pressure).

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