| | Setup: DIB1/3/4 → 3.2 MHz filters 2/3/1 → cable 3/1/2 → gender changer 3/?/2 → HVConn 1/3/2 → HV 1/2 → DCRC55(1)/DCRC50(3) |
| 0001 | P2 finally falls into readable range. It's falling steeply and oscillating slightly. |
| 0003 | G1/G2 = 413/381 mbar, P1 = 0.10 mbar, Tower → 77.6 mK, 1K pot = 1.71 K / 85 mbar (and falling). |
| 0017 | P2 has fallen to 20 mbar and is not oscillating. This still doesn't seem stable and likely won't last the night. Close V6 to stop circulation. |
| 0022 | Open V9 and V3, turn off 3He pump. |
| 0100 | Tower has risen to 1.2 K |
| 0949 | Tower/MC/Coldplate = 1.66/1.83/3.0 K, Still = 2.4 K/>1000 mbar/3.5 mW, G1/G2 = 39.5/34.4 mbar, 1K Pot = 1.36 K/1.4 mbar, MB = 40.2% |
| 0954 | Fill LN2 cold trap full. |
| 1116 | Close 1K pot needle valve and re-open 1 full turn (about +45degrees from previous position). 1K pot → 2.6 K and falling / >1000 mbar |
| 1120 | Close V9, leaving 40.5 mbar in dump. Turn on 3He pump, close V3, open V6 → 12.4% to start circulation through trap 1. |
| 1130 | 4He pump suddenly gets very loud, and is smoking a little bit. 1K pot = 2.5 K / >1000 mbar. Close needle valve 1/4 turn, no change. Close needle valve completely. 1K pot → 1.4 K / 4 mbar , but pump is still noisy. 1K pot line is also frosty past the speedivalve. |
| 1133 | P2 = 4 mbar. Close V4A momentarily and P2 → <0.1 mbar, but pump is still noisy. 4He pump oil level is also at 0. |
| 1137 | Oh wait, it's the 3He pump that's noisy! |
| 1140 | Let's do this more slowly. Open needle valve 20 degrees. 1K pot → 1.41 K / 2.8 mbar |
| 1140 | Condenser peaked at 60 mbar, but has fallen to 39 mbar since I slowed the 1K pot. V6 → 12.8% |
| 1142 | The pumps seem happier now. The 3He pump is around normal volume and the 3He pump is not smoking. The 1K pot line has also thawed. we must have gotten LHe way up in the pot or something and the 4He pump couldn't take it. Maybe that's a good sign though that the needle valve can be opened far enough to get decent flow? |
| 1145 | Condenser pressure is settling at 37 mbar. 1K pot = 1.40 K / 2.6 mbar. |
| 1146 | V6 → 13.2%. Condenser peaks at 137 mbar, Tower = 1.68 K, 1K pot = 1.40 K / 3.0 mbar |
| 1155 | Open 1K pot needle valve +10 degrees. 1K pot → 1.44 K / 3.8 mbar. P2 changed smoothly from 3 to 3.8 when I did this. It didn't go off scale like it has been. |
| 1159 | Condenser pressure has risen to 152 mbar since tweaking the 1K pot. |
| 1215 | Condenser pressure = 186 and rising but flattening off. 1K Pot = 1.46 K / 4.5 mbar and oscillating a little bit. |
| 1304 | Condenser pressure peaked at 196 mbar and is finally coming down. Condenser = 179 mbar, 1K pot = 1.41 K / 2.8 mbar |
| 1305 | V6 → 13.4%. |
| 1346 | Condenser pressure has flattened out around 360 mbar and P1 = 85.0 mbar |
| 1350 | Open 1K pot needle valve +10 degrees. P2 rises to 20 mbar, then starts to oscillate around 7 mbar. 1K pot temp = 1.5 K. Still pressure (P1) climbs to 800 mbar |
| 1400 | Condenser pressure = 360 mbar. V6 → 13.6%. Condenser pressure → 420 mbar , P1 → 15 mbar, Tower = 1.6 K |
| 1410 | Condenser pressure = 430 mbar , P1 → 9.5 mbar, Tower = 1.4 K, 1K pot = 1.49 K / 5.0 mbar |
| 1440 | Condenser pressure = 426 mbar, P1 = 8.5 mbar. V6 → 13.8%. |
| 1512 | Condenser pressure peaked at 454 mbar, now 438 mbar. P1 = 4.0 mbar, Tower = 1.3 K. V6 → 14.0%. |
| 1520 | Commence LHe transfer (MB=31.6%) |
| 1601 | Condenser = 420 mbar. V6 → 14.2%. G1 slowly rises to 427 mbar |
| 1605 | 1K pot = 1.40 K / 3.4 mbar. Open needle valve +10 degrees. P2 peaks at 35 mbar, then start to settle to ~ 5 mbar |
| 1618 | Cease LHe transfer (MB = 91.1%) |
| 1627 | Condenser pressure = 463 mbar, slowly climbing. Tower = 1.2 K |
| 1700 | Fill LN2 cold trap full. |
| 1731 | Condenser = 468 mbar, 1K pot = 1.49 K / 6.0 mbar. Tower = 1.2 K. The mix in G1 doesn't seem to want to condense even though the 1K pot is at 1.5 K. I'm going to keep waiting for the condenser pressure to come down before opening V6 any more. |
| 2014 | 1K Pot = 1.37 K / 2.26 mbar. Open Needle Valve +10 degrees. 1K Pot → 1.62 K and falling / 25 mbar and falling |
| 2026 | Tower Temp = 1.05 K G1/G2 Stable at 472/432 |
| 2037 | 1K Pot still dropping, though it looks like it may be levelling off. 1K Pot → 1.57 K / 12.5 mbar |
| 2157 | Condenser pressure = 473 mbar and flat. 1K pot = 1.48 K / 5.5 mbar. Open Needle Valve +10 degrees. P2 rises to 45 mbar then starts falling. |
| 2203 | G1 = 475 mbar, P1 = 1.5 mbar, Tower = 1.1 K. The mix just isn't condensing. Maybe I'm trying to condense too much too fast? Let's slow circulation a bit. Reduce V6 to 13.4 %. G1 starts to fall slowly, P1 increases to 6 mbar |
| 2209 | Open 1K pot needle valve +10 degrees again. 1K pot pressure rises to 75 mbar before starting to oscillate around 30 mbar. 1K pot temp = 1.64 K |
| 2213 | G1 is flattening out to 430 mbar. The Still heater is at 3.5 mW. Let's try turning this off till we're colder. P1 falls from 8 mbar to 5 mbar |
| 2215 | 1K pot= 1.60 K / 19 mbar. |
| 2217 | Leave it like this overnight. Condenser pressure is falling slowly, so hopefully we're actually condensing mix with this restricted circulation (V6=13.4%). Once the condenser pressure is really low in the morning, we can open V6 a little bit more. |
| 2316 | G1 = 340 mbar, P1 = 4.0 mbar, P2 = 6.0 mbar. |