2022/02/16 (Wednesday)
- Lab in-personnel: Matt
| Status | Run 75 in progress |
|---|---|
| Setup | Tower Faces 5/3/2 → Cables 2/1/3 → nothing/diverter_board+extra_board/nothing → Side2-readout HVboard CONN1/2/3 → HV1/2 → DCRC55(1)/50(3) Lead shield in place. Am Source y = 0.03 mm |
| Skipped LHe transfer yesterday to begin warmup today | |
| 1100 | 1K Pot pressure has fallen to 7 mbar. Probably the bath level is below the 1K Pot siphon so the LHe in the pot is getting pumped away. |
| 1200 | 1K Pot pressure starts dropping fast. 1K Pot temperature 1.51 K. |
| 1210 | Goldman/Tower/MC(H35)/Coldplate = 43.3/116/35.8/194 mK, Still = 1.85 K / 0.280 mbar / 1.0 mW, G1/G2= 405/380 mbar, 1K Pot = 4.1 K / 2.4 mbar, MB = -1.0% |
| MB was at -0.6% when I updated it so it must have hit the minimum reading within the last hour. | |
| 1215 | 1K Pot temperature shoots up above 3.5 K, clearly it's empty now |
| 1225 | Condenser pressure is rising, should stop circulation. |
| 1230 | Close V6 to stop circulation. This allows mix to expand into still line |
| 1232 | Condenser (G1) = 525 mbar and falling. Still (P1) = 38 mbar and rising. |
| 1235 | 1K Pot = 5.0 K / 2.4 mbar. |
| 1235 | Goldman (Tower) = 0.58 K and rising. |
| 1240 | Close 1K Pot needle valve and speedivalve. Switch 4He pump outlet valve from Recovery to Exhaust. Close red 4He Pump Recovery valve. |
| 1245 | Close V4a and the 4He Pump inlet valve. Then turn off 4He pump. |
| 1245 | Goldman = 1.3 K and rising. Condenser (G1) = 245 mbar and falling. |
| 1250 | Open V3 to let mixture from Condenser side to Still side. G1 falls to 154 mbar. |
| 1250 | 1K Pot = 7.0 K (max) |
| 1250 | Turn off DAQ programs, then power down DCRC1&3. |
| 1255 | Turn off 3He pump |
| 1305 | Fill LN2 cold trap bath. |
| 1515 | Tower(Goldman) = 1.73 K. MC(Cernox)/MC(H35) = 1.76/1.93 K |
| 1520 | Turn off Kepco HV supply. Then power down DCRC2. |
| 1555 | Let 5.6 mbar He gas into pumping station manifold, then let this into the IVC. IVC → 0.22 ubar. |
| MC(Cernox) temperature shoots up to 3.0 K | |
| 1602 | Recovery = 540000 cuft / rising 14 cuft/hr |
| 1620 | Let 2.5 mbar He gas into vacuum manifold. Then open cryostat vacuum jacket valve to let this into the vacuum jacket. Vacuum Jacket → 0.046 mbar. |
| 1625 | Recovery = 307 cuft/hr |
| 1625 | MC(Cernox) = 4.0 K, Condenser(G1) = 877 mbar. We should release this pressure into the dump soon. |
| 1630 | Open V9 to let mixture into the dump. |
| Condenser pressure drops to 500 mbar, MC temperature falls for a minute but then rises. | |
| 1635 | MC(Cernox) = 4.9 K. Good time to pump the mixture to the dump. |
| 1640 | Start pumping mixture to dump (close V13a, turn on 3He pump. All other circulation loop valves open as well as V9 and V3. Open V6 to 13%. After P1 falls into range open V6 to 30%.) |
| 1645 | Close Still gate valve and V1, to pump just on LN2 Trap 1 until it's empty. |
| 1649 | Recovery = 540100.0 cuft (@ 16:49:55) |
| 1650 | Isolate LN2 Trap 1 which is now pumped out to dump (close V12a) |
| 1650 | Continue pumping on the fridge lines (open V1 and Still Gate Valve) |
| 1705 | Stop pumping out fridge (close V1, V3, Still Gate valve, Condenser speedivalve). G1(Dump) = 729.5 mbar |
| Barometric pressure = 29.92“ (source is https://w1.weather.gov/data/obhistory/KMSP.html.) G2 = 729.9 mbar. Corrected dump pressure = 729.9 mbar. Actually higher than Run 71. |
Ptrue[mbar] = Pdisplay[mbar] + ( Pbar[inHg] - 29.92 ) * 33.86
| 1715 | Recovery = 100 cuft/hr |
|---|---|
| 1725 | MC(Cernox) = 8.53 K. Sorb = 14.9 K |
| 1725 | Close V6. G2 = 731.6 mbar. Corrected dump pressure = 731.6 mbar. |
| 1735 | Isolate dump (close V9) and turn off 3He pump. |
| 1751 | Recovery = 540200.0 cuft (@ 17:51:48) |
| 1800 | Recovery = 60 cuft/hr |
| 1900 | Recovery = 13 cuft/hr |
| 1919 | Recovery = 540250.0 cuft (@19:19:36) |
| 2000 | Recovery = 5.4 cuft/hr |
| 2100 | Recovery = 3.3 cuft/hr |
| 2137 | Recovery = 540260.0 cuft |
| 2400 | Recovery = 0.7 cuft/hr |
| 0300 | Recovery = 0.41 cuft/hr |
| 0600 | Recovery = 0.26 cuft/hr |
| 0855 | Recovery = 540267.0 cuft |
| 0900 | Recovery = 0.20 cuft/hr |