2022/10/10 (Monday)
- Lab in-personnel: Matt
| Status | Run 76 in progress |
|---|---|
| Setup | Cables 2/3/1 → diverter/nothing/nothing → Side2-readout HV CONN 1/3/2 → HV 1(L)/2(R) → DCRC50(3)/DCRC55(1), DCRC33(2)→HV control, NaI trigger signal → DCRCX(4) Lead/poly shield fully assembled. Boron-filled socks covering NaI detectors. PuBe source behind lead wall on West side of lead/poly shield. |
| NaI trigger window: 7.6-11.2 MeV | |
| warmed up yesterday for 13th 5K pumpout. But didn't start pumping out the IVC yet. | |
| 1120 | MC/1KPot/Sorb = 5.31/5.58/7.0 K. |
| 1120 | Unplug DCRCs 1&3 |
| 1120 | Check pressure in IVC: 0.16 ubar. |
| 1120 | Start pumping out IVC with turbo pump |
| 1235 | MC = 7.54 K |
| 1235 | Turbo on IVC = 2.2 ubar. With Turbo valve out for 1 minute, IVC = 46 nbar |
| interestingly with Turbo valve out for several minutes, MC temperature starts falling rather than rising. I may have expected the pressure to already be low enough to break the thermal link to the bath. But it looks like active pumping is necessary to keep the MC warming. | |
| after about 20 minutes the MC temperature kinda flattened out | |
| 1255 | Pry the stripline elbow up by wedging a screwdriver between the knurled knobs and put a couple of washers in the gap to hold it up. Try pushing some vacuum grease into the gap, a little more effort than last time - cut the wooden end of a swab down a bit into a flat shape to try to push the grease upward into the gap between the knurled knob and the stripline tube. Do this all the way around. Then remove the washers and push the elbow down again. |
| 1405 | Restart turbo-pumping IVC |
| 1500 | MC/1Kpot/Sorb = 10.10/>7/9.8 K Turn off MC and Still heaters |
| 1538 | Begin LHe transfer @ MB = 34.8% |
| 1545 | Fill LN2 cold trap bath |
| 1623 | End LHe transfer @ MB = 95.6% |