| | 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) |
| | Weekend: Circulation stopped. 1K pot still pumping. Tower temp around 1.6K |
| 0929 | Tower/MC/Coldplate =1.63/2.1/2.6 K, Still = 2.1 K / - mbar, G1/G2 = 28/30 mbar, 1K Pot = 1.38±0.01 K / 1.8 mbar. MB = 37.2% |
| 0935 | Fill LN2 cold trap. |
| 0940 | Wiggle needle valve back and forth +/- 10 degrees, but leave it in the same position it started in. P2 starts slow oscillation around 15 mbar. |
| 0945 | Close V9, leaving 30.2 mbar in dump. Turn on 3He pump, close V3, open V6 → 12.8% to start circulation through trap 1. |
| 0950 | Condenser pressure peaks at 94 mbar, Tower = 1.63 K |
| 0955 | 1K pot = 1.50 K / 5.5 mbar |
| 0957 | V6 → 13.2%. Condenser peaks at 126 mbar. Tower → 1.45 K. Still pressure falls into readable range. |
| 1023 | V6 → 13.6%. Condenser rises 230 mbar. Tower → 1.32 K. |
| 1037 | 1K pot = 1.44 K / 3.6 mbar |
| 1040 | Open 1K pot +10 degrees. 1K Pot → 1.6 K / 20 mbar. |
| 1047 | Condenser continues to rise slowly to 250 mbar. |
| 1229 | Condenser peaks at 270 mbar, falls to 220mbar. Tower → 1.32 K. V6 → 14.0%. Condenser rises 370 mbar. Tower → 1.12 K. |
| 1233 | P2 = 3mbar. Open 1K pot +10 degrees. |
| 1250 | V6 → 14.4%. Condenser keeps settling to 142 mbar. Tower → 900 mK. |
| 1317 | V6 → 14.8%. Condenser keeps settling to 130 mbar. Tower → 783 mK. |
| 1330 | Open V6 → 100%, Condenser settles to 128 mbar, Tower → 581 mK, Still = 0.06 mbar. |
| 1345 | Tower = 500 mK, 1 K pot = 1.49 K / 5.5 mbar |
| 1350 | Open V14 to let the rest of the mix into circulation. Condenser/Still peak at 180/17 mbar |
| 1430 | Still = 0.38 mbar, Tower = 103 mK. Close V14. |
| 1441 | Tower = 67.1 mK and falling. P1 = 0.050 mbar. 1K pot = 1.49 K / 5 mbar. |
| 1445 | The 1K pot keeps running dry and the still pressure is low. Let's try a little Still heating to see if that improves 1K pot stability. Set Still heater to 0.5 mW. P1 → 0.06 mbar, P2 = 5.0 mbar |
| 1450 | Set Still heater = 1 mW. P1 → 0.065 mbar, P2 = 5.0 mbar |
| 1450 | Set Still heater = 2 mW. P1 → 0.085 mbar, P2 = 5.0 mbar |
| 1455 | Tower = 48.0 mK and continues to cool. |
| 1456 | Set Still heater = 3 mW. P1 → 0.10 mbar, P2 = 5.0 mbar |
| 1500 | Tower = 37.6 mK |
| 1501 | Set Still heater = 3.5 mW. P1 → 0.11 mbar, P2 = 5.0 mbar. Well, this is the sort of Still pressure we are used to running at. P2 hasn't increased, but it doesn't seem to be falling yet either. |
| 1506 | Tower = 34.6 mK, Still = 1.44 K / 0.11 mbar, G1/G2 = 172/165 mbar, 1K Pot = 1.48 K / 4.5 mbar |
| 1515 | Commence LHe transfer (MB=28.8%). Don't precool transfer tubes, just wait ~15 seconds for air to be pushed out when inserting into the bath and dewar. |
| 1555 | Since starting LHe transfer, Tower temp has risen from 33.6 mK to 73.4 mK. Perhaps due to not precooling the transfer tubes. |
| 1518 | Cease LHe transfer (MB=90.32%). Tower = 107 mK, P1=0.11 mbar, P2 = 5.0 mbar |
| 1640 | Tower temp continues to increase to 119 mK. Try reducing Still heating to 2 mW. P1→0.085 mbar, but Tower temp continues to increase. Return Still heater to 3.5 mW. |
| 1656 | Since we started Still heating at 1445, G1/G2 have been rising steadily to 442/410 mbar. This is a bit high. |
| 1700 | 1K pot = 1.45 K / 5 mbar. Open 1K pot needle valve +10 degrees. 1K Pot → 1.56 K / 13 mbar. |
| 1715 | Tower temp = 132.4 mK, G1/G2 flat at 443/411 mbar |
| 1728 | Fill LN2 cold trap partially. |
| 1735 | Start logging pressures in vuk-01:i\K100\20180611_pressure_log.txt |
| 2018 | Tower = 94.1 mK, G1/G2 = 389/365 mbar, P1 = 0.95 mbar, P2 = 1.8 mbar |
| 2250 | Tower = 103 mK, G1/G2 = 409/380 mbar, P1 = 0.95 mbar, P2 = 1.9 mbar |