2021/04/14 (Wednesday)
- Lab in-person: Matt
- Virtual partner: Derek
| Status | Run 74 in progress. Warmed up a second time to fix the DIB2qI short which reappeared at around 130 K. Tower installed yesterday, IVC pumping out overnight. Cryostat Vacuum Jacket pumped out. Mixture in dump. |
|---|---|
| 1255 | Matt enters lab |
| 1255 | Turbo on IVC = 40 nbar. With Turbo valved out for 1 minute, IVC = 860 nbar. |
| 1330 | Leak Detector on IVC with Turbo valved out for 1 minute: 36.8 pbarL/s |
| 1405 | Check contents of warm LN2 Trap 1: 7.2 mbar. (This is left over from the LN2 transfer last week.) Pump out with scroll pump. |
| 1415 | Check contents of warm LN2 Trap 2: 1.2 mbar. (This one was pumped out a week ago.) Pump out with scroll pump. |
| 1420 | Start cryocleaning mixture through LN2 Cold Trap 1, V6 = 12.2% |
| 1425 | Increase V6 → 12.4% to restart flow |
| 1435 | Increase V6 → 12.5% to restart flow |
| 1440 | Increase V6 → 12.6% to speed up flow |
| 1500 | Increase V6 → 12.7% to speed up flow |
| 1520 | Stop cleaning through Trap 1 after 60 min. G2 flow pressure was 575-730 mbar. Pump mixture to dump. Removed 7.6 mbar. |
| 1435 | Tighten IVC bolts a few more times |
| 1455 | LD on IVC = 44 pbarL/s. Squirt around IVC seal - no increase seen. Squirt around stripline elbow: → 170 pbarL/s. |
| 1510 | Remove clean tent from fridge and move it into pump alley |
| 1515 | Attach MB fill funnel to fridge. |
| 1525 | Remove covers from pit |
| 1555 | Start cryocleaning mixture through LN2 Cold Trap 2, V6 = 12.6% |
| 1605 | Increase V6 → 12.8% to restart flow |
| 1615 | Increase V6 → 12.9% to speed up flow |
| 1635 | Increase V6 → 13.0% to speed up flow |
| 1655 | Stop cleaning through Trap 2 after 60 min. G2 flow pressure was 570-725 mbar. Pump mixture to dump. Removed 4.2 mbar. |
| 1555 | Raise MB |
| 1600 | Replace covers on pit |
| 1635 | Start bolting MB to fridge stand. This method seemed to work well: first, raise MB till almost touching. 2nd, put 3 medium bolts on bottom to line it up - need to rotate and push back and forth to find the holes. 4th, try putting some small bolts on the top. Could only get a few, the rest weren't lined up. Put some in but leave a few mm. 5th, remove medium bolts from the bottom. 6th, put the rest of the small bolts in, pushing the MB around a bit to line them up. Then they can go in pretty easy. Put all of them in and tighten till they are touching, then will proceed with inserting and tightening medium and large bolts, then finish tightening small ones. Note: using two washers on each of the small bolts. |
| 1655 | Having difficulty putting in the medium bolts. Some have gone in but others aren't aligned well. The fridge insert seems to be rotated somewhat with respect to the fridge stand. And the brackets holding the insert to the stand don't seem to be designed to adjust the rotation really. |
| 1715 | After getting all the small bolts snug, loosen all the bolts in the slotted sections of the three fridge insert brackets (2 in each bracket). Then get the top bolts in by pulling the MB+fridge back and forth a bit. Then do the same with the medium bolts on the bottom. |
| 1735 | After tightening all the MB bolts, retighten the fridge bracket bolts. Note - one of the small bolts does not go in easily, which sucks because it leaves two bad holes in a row. Instead of leaving it out I put 5 or 6 washers on it, then I was able to tighten it down OK. |
| 1740 | Matt exits lab |