2024/02/10 (Saturday)
- Lab in-personnel: Himangshu
| Status | Did a 10K pumpout to see if we can lower down the G1/G2 pressures. Begin another cooldown |
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| 1418 | Fill LN2 cold trap dewar |
| 1419 | MC(H35)/1KPot = 6.28/6.99 K . Both are at higher temperatures than earlier |
| 1421 | 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 by opening the 1Kpot speedivalve(with V4a open, 4He pump inlet valve closed). 1K Pot = 0.23 bar ((30-23=) 7 inHg) on mechanical gauge. |
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| 1430 | 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. |
| 1435 | Open 4He pump valve fully |
| 1436 | MC(H35) = 6.27 K, flatenned, 1K Pot = 3.39 K / 1.1 mbar, MB = 37.2% enough to start 1K Pot. |
| 1439 | Open 1K Pot needle valve → 15° (half a unit mark). 1K Pot (P2) → 3.09 K / 6 mbar |
| 1441 | MC(H35) = 6.24 K, Open 1K Pot needle valve → 30°. 1K Pot → 2.45 K / 26 mbar. |
| 1443 | MC temp dropping |
| 1420 | MC(H35)/1Kpot = 3.18/1.9 K, MC temp dropping linearly. G1/G2 = 338/318 mbar . 1K Pot(P2) = 26 mbar. |
| 1450 | We will stop the 1Kpot to do the LHe transfer to avoid putting ice inside the 1Kpot |
| 1451 | |
| 1438 | MC temp is around the He transition point (2.17K), P2 = 13 mbar |
| 1511 | MC(H35)/1Kpot = 1.90/1.61 K and flat. G1/G2 = 48.6/51.0 mbar . 1K Pot(P2) = 20 mbar. |
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| 1512 | Close V3 and V9, leaving 51.0 mbar mixture in dump. |
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| 1513 | Turn on 3He pump |
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| 1515 | Start circulation through Trap 1. V6 → 12.6%. Condenser(G1) peaks at 329 mbar. MC(H35) → 1.45 K. Still → 1.48 K / 26 mbar. |
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| 1525 | V6 → 13.0%. Condenser(G1) peaks at 244 mbar. MC(H35) → 1.25 K. Still(P1) → 1.28 K / 6.0 mbar. |
| 1530 | V6 → 13.4%. Condenser(G1) peaks at 252 mbar. MC(H35) → 1.14 K. Still(P1) → 1.17 K / 3.8 mbar. |
| 1535 | V6 → 13.8%. Condenser(G1) peaks at 248 mbar. MC(H35) → 1.05 K. Still(P1) → 1.12 K / 2.2 mbar. |
| 1540 | V6 → 14.4%. Condenser(G1) peaks at 254 mbar. MC(H35) → 0.85 K. Still(P1) → 1.11 K / 1.2 mbar. |
| 1545 | V6 → 15.0%. Condenser(G1) peaks at 256 mbar. MC(H35) → 0.62 K. Still(P1) → 1.11 K / 0.75 mbar. |
| 1553 | V6 → 100.%. Condenser(G1) peaks at 257 mbar. MC(H35) → 0.24 K. Still(P1) → 1.05 K / 0.2 mbar. |
| 1639 | MC(H35) = 31.8 mK, Tower(Rox) = 64.9 mK and pretty flat, G1 = 172 mbar and pretty flat. 1K Pot = 1.61 K / 20 mbar. |
| 1641 | Open V14 to pull the rest of the mixture out of the dump into circulation. |
| 1644 | MC(H35) rises to 75 mK (Tower Rox to 89 mK), Still rises to 70 mbar then falls again, Condenser(G1) rises to 255 mbar. 1K Pot unaffected. |
| 1733 | P1 = 0.38 mbar (<1), close V14 |