| | Status: Warming to RT. Big leak at a low IVC seal at 77K. Several cryocleanings done, mixture exposed to cold LN2 Trap 2 over the weekend. Cryostat vacuum jacket pumped out. 1K Pot evacuated and isolated. |
| 0915 | MC(Cernox) = 288.2 K |
| 0915 | Fill LN2 cold trap bath. |
| 0920 | Pump mixture out of cold LN2 Trap 2 to dump. Then remove Trap 2 from LN2 bath to let warm up. |
| 0925 | Begin cryocleaning mixture through cold LN2 Trap 1, V6 = 12.4% |
| 0930 | Increase V6 → 12.8% to reestablish flow |
| 0935 | Lower main bath |
| 0945 | Tighten screws on stripline tube IVC port flange. These definitely have some give. |
| 0950 | Increase V6 → 13.0% to reestablish flow |
| 0955 | Tighten screws on middle IVC flange. These also have some give. Also tightened the ones on the top flange, though this one is probably ruled out as the leaky one. |
| 1000 | Leak check IVC, background 18 pbarL/s. Squirt checks at IVC seals, no leaks seen. |
| 1005 | Erect clean tent around fridge. |
| 1015 | Fill IVC with 1 bar N2 |
| 1020 | Open IVC, remove lower IVC can |
| 1030 | Put new indium o-ring on IVC bottom can, reattach IVC bottom can |
| 1045 | Quick electrical check on DIB1&2, look good |
| 1045 | IVC screws mostly tightened. Begin pumping out IVC with scroll pump |
| 1055 | Begin pumping out IVC with turbo pump |
| 1055 | warm LN2 Trap 2 = 14.0 mbar. The mixture was open to this trap over the weekend. Pump out Trap 2 with scroll pump. |
| 1125 | Leak check IVC. Seeing a small leak at the top of the fridge either around the stripline tube or the flange where the stripline elbow meets the T pipe. Background around 13 pbarL/s, during squirt test with hypodermic signal rises to about 25 pbarL/s. |
| 1150 | Taped a bag around the KF flange of the stripline elbow, and tried some more targeted squirt checks. Shooting a blast into the bag produced a strong increase in signal to around 200 pbarL/s. Squirting a strong blast around the top of the stripline tube produced a roughly similar increase. Attempting more controlled amounts in each location produced almost no signal increase. There is definitely some sense that that KF seal is leaky. We'll let it back up to 1 bar then reseat the o-ring of this seal. |
| 1205 | Fill IVC with 1 bar N2 |
| 1225 | Take clamp off KF seal between stripline elbow and T-pipe. Noticed that the T-pipe tensions the stripline elbow upward - adjusted the position of another clamp on the T (the perpendicular port) so that it lies lower on the fridge rack. Clean flanges on the elbow/T-pipe connection, put a little grease on the o-ring. Take this opportunity to tighten the knurled knobs at the bottom of the stripline elbow. It looks like there's less stress on the elbow now. Replace the clamp on the elbow/T-pipe connection. |
| 1230 | Start pumping out IVC with scroll pump |
| 1235 | Begin cryocleaning mixture through cold LN2 Trap 2, V6 = 12.9% |
| 1240 | Start pumping IVC with turbo pump |
| 1240 | Increase V6 → 13.0% to reestablish flow |
| 1300 | Increase V6 → 13.2% to reestablish flow |
| 1345 | Leak check IVC again. There are still noticeable leaks at the elbow/T-section KF seal, and at the stripline tube/elbow seal. Signal base around 40 pbarL/s, went up to about 45 with needle-squirts at these areas. With big blasts the leak went as high as 120 pbarL/s. Maybe not quite as bad as before but similar. No leaks seen at any of the IVC indium seals. |
| 1345 | Stop cleaning mixture. Pump mixture out of Trap 2 back to dump. |
| 1355 | Raise main bath. |
| 1415 | warm LN2 Trap 1 = 20.6 mbar. Why so high??? Pump this out with scroll pump |
| 1435 | Pump out 1K Pot with scroll pump |
| 1440 | Pump out fridge with scroll pump |
| 1500 | warm LN2 Trap 2 = 7.4 mbar. Pump this out with scroll pump |