2020/11/05 (Thursday)
- Lab in-person: Ruiren
- Virtual partner: Matt
| Setup | Run 73. DIB 1/3/4 → Stripline 43/48/41 → pi-filters 1/2/3 → Cable 3/1/2 → nothing/nothing/accessory_interposer → HV_Conn 1/3/2 → HV 1/2 → DCRCX(4)/DCRC55(1)-master; DCRC33(2) → HV control. DCRCs on. Lead/poly shield erected (4 lead walls, 2 poly walls). |
|---|---|
| 0659 | MB = -0.5% |
| 0725 | Tower thermometer = 62.8 mK |
| 0725 | Stop circulation: close V6. After about 5 minutes Tower temperature and Still pressure start to rise, Condenser pressure starts to fall. |
| 0745 | Turn off 3He pump |
| 0750 | 1K Pot temperature and pressure drop, 1.61 K / 17 mbar → 1.53 K / 6.5 mbar. Probably the pot has now run dry. As long as pressure stays low I guess we'll keep pumping on it, until we can close the manual valves. |
| 0830 | 1K Pot pressure drop, temperature rise: 1.6 K / 7 mbar → 4.1 K / 4 mbar. I guess maybe at 7:50 the pot stopped filling, and now the last liquid in the pot is gone. |
| 0840 | G1/G2 = 79/71 mbar, falling. Open V3 to short the condenser and still sides. G1/G2 fall to 40/47 mbar. |
| 0840 | Tower = 1.20 K, rising |
| 1000 | Tower thermometer = 1.44 K, rising slowly. G1(fridge) = 54 mbar, rising. 1K Pot = 4.5 K |
| 1235 | Tower thermometer = 1.58 K, rising slowly. G1(fridge) = 111 mbar, rising. 1K Pot = 5.3 K, rising steadily |
| 1235 | Turn on MC/Still heaters to 20/30 mW |
| 1250 | Tower = 2.9 K, G1(fridge) = 272 mbar, both rising sharply. (1K Pot temperature fell, I guess from cool mixture flowing past it. ) |
| 1320 | Tower = 3.9 K, G1(fridge) = 820 mbar Start pumping mixture to dump: 3He pump on, open V9, close V13a, open V6 → 12.8%. Pumping mixture out of fridge and trap to dump. |
| Tower drops below 3K, cooling effect of pumping out mixture. | |
| 1325 | G1 (fridge) = 118 mbar, G2(dump) = 546 mbar. Close V6 for now, to let Tower temperature rise again. |
| 1345 | After steadily rising from 2.5 to 3.3 K, Tower started rising much more quickly, now > 5K. G1(fridge) has risen from 100 to 440 mbar. Let's pump more mixture out. |
| 1350 | Open V6 to 12.8% again, to pump mix out of trap and fridge to dump. |
| Cooling effect on Tower again but small, from 5.8→5.7 K, then starts rising again. | |
| 1350 | Open V6 a little more, 13%. G1(Fridge) falls below 20 mbar and P1 falls into range. Tower temperature continues to rise, >6 K. Open V6 to 30%. |
| 1355 | Close V3, V1, and V6, open V5. Now we're pumping out Trap 1 only. We'll do that for a little while. |
| actually since there's no remote access to V12a speedivalve, we can't really pump out Trap1 by itself completely. I'll just open V3, V1, V6→30% again. | |
| Ruiren temperature = 36.7 C | |
| 1420 | Ruiren enters lab |
| 1430 | Close 1K Pot Needle Valve and Speedivalve, close V4a and valve at 4He pump, switch 4He pump outlet to Exhaust, close Recovery valve from 1KPot exhaust, turn off 4He pump. |
| 1435 | Switch to pumping only on cold LN2 Trap 1 to dump for a few minutes, then close V12A+speedivalve. |
| 1440 | Switch to pumping out fridge to dump, V6 = 30% |
| 1440 | Tower = 10.3 K, G1 = 1.5 mbar, P1 = 0.024 mbar. We should stop pumping fridge now. |
| 1445 | Close Condenser speedivalve and Still gate valve |
| 1445 | Stop DAQ programs, then unplug power from DCRC1&4. Turn off HV supply power switch, then unplug DCRC2. |
| 1450 | Turn off GWINSTEK power supply to source mover driver board, then unplug Arduino. |
| 1455 | Turn on camera to monitor recovery meter every 2 minutes |
| 1640 | Tower = 16.2 K. Close V1, should have closed it earlier. Close V3, V5, V6. |
| 1645 | G2(dump) = 740.0 mbar. |
| 1730 | G2(dump) rose suddenly, now 742.5 mbar, not sure why it changed. |
| 1730 | Turn off 3He pump |
| 1730 | Tower/Sorb = 17.4/23.9 K |
| 1903 | Recovery = 404699.98 cuft, 12.8 cuft/hr (19:03:14) |