2023/02/19 (Sunday)
* Lab in-personnel: Zach
| Begin another cooldown | |
| 1132 | Turbo on IVC = 1.2 nbar, with turbo valved out for a min IVC = 14 nbar |
| 1133 | Open up turbo again, close IVC valves on top of fridge |
| 1137 | Begin LHe transfer @ MB = -1.0% |
| 1140 | Turn on 4He pump. Open Recovery valve to 4He pump. Pump out line to 1K pot (open V4a, close 1K pot speedivalve and slowly open the 4He-pump inlet valve).Close the 4He-pump inlet valve once done. Check pressure in 1K Pot (with V4a open, 4He pump inlet valve closed). 1K Pot = 0.23 bar (-23 inHg) on mechanical gauge. |
| 1145 | Pump out 1K Pot slowly, opening the 4He pump valve until it just starts to make noise, then opening it more when it becomes more quiet. |
| 1146 | Open 4He pump valve fully. |
| 1147 | Fill LN2 cold trap dewar |
| 1150 | MC(H35) = 5.50 K, 1K Pot = 3.37 K / 2.4 mbar |
| 1155 | MB = 36.6%, thats enough. Open 1K Pot needle valve → 15° (half a unit mark). 1K Pot (P2) → 2.77 K / 9.0 mbar |
| 1200 | MC temp dropping |
| 1203 | Open 1K Pot needle valve → 30°. 1K Pot → 2.07 K / 24 mbar. |
| 1210 | MC(H35) = 3.03 dropping linearly. G1/G2 = 275/272 mbar . 1K Pot(P2) = 1.75 K / 24 mbar. |
| 1229 | Ended LHe transfer @ MB = 92.5% |
| 1233 | P2 dropped to 12 mbar, MC(H35) = 2.24 K, about the transition point |
| 1243 | Plug in DCRCs |
| I will do the rest of the cooldown remotely | |
| 1306 | MC(H35)/1Kpot = 1.90/1.61 K and flat. G1/G2 = 51/54 mbar . 1K Pot(P2) = 20 mbar. |
| 1307 | Close V3 and V9, leaving 53.6 mbar mixture in dump. |
| 1307 | Turn on 3He pump |
| 1308 | Start circulation through Trap 1. V6 → 12.6%. Condenser(G1) peaks at 326 mbar. MC(H35) → 1.53 K. Still → 1.65 K / 40 mbar. |
| 1317 | V6 → 13.0%. Condenser(G1) peaks at 206 mbar. MC(H35) → 1.21 K. Still(P1) → 1.39 K / 5.5 mbar. |
| 1321 | V6 → 13.4%. Condenser(G1) peaks at 255 mbar. MC(H35) → 1.17 K. Still(P1) → 1.35 K / 4.5 mbar. |
| The MC temp went up a bit (to 1.3K) before going down again | |
| 1331 | V6 → 13.8%. Condenser(G1) peaks at 204 mbar. MC(H35) → 0.94 K. Still(P1) → 1.27 K / 2.4 mbar. |
| 1340 | V6 → 14.4%. Condenser(G1) peaks at 210 mbar. MC(H35) → 0.59 K. Still(P1) → 1.30 K / 1.3 mbar. |
| 1347 | V6 → 15.0%. Condenser(G1) peaks at 207 mbar. MC(H35) → 0.38 K. Still(P1) → 1.29 K / 0.75 mbar. |
| 1356 | V6 → 100.%. Condenser(G1) peaks at 198 mbar. MC(H35) → 0.16 K. Still(P1) → 1.24 K / 0.15 mbar. |
| Still temp and G1 are kinda high | |
| 1427 | MC(H35) = 45.8 mK and pretty flat, G1 = 144 mbar and pretty flat. 1K Pot = 1.62 K / 20 mbar. |
| 1427 | Open V14 to pull the rest of the mixture out of the dump into circulation. |
| 1428 | MC(H35) rises to 91 mK then falls, Still rises to 90 mbar then falls, Condenser(G1) rises to 220 mbar then falls. 1K Pot unaffected. |
| 1449 | P1 = 0.95 mbar (<1), close V14 |
| MC and still are settling at 43 mK and 1.26 K, higher than usual |