2018/08/06 (Monday)
| status: Trying to stretch LHe bath over the weekend. | |
| 0912 | MC(Cernox) = 5.7 K, Sorb/1K Pot = 9.4/>6.99 K, Turbo on IVC = 1.0 nbar, G1(fridge)/G2 = 559/509 mbar. P1/P2 = 1000/3.4 mbar. MB = 24.1% |
| 0915 | Fill LN2 cold trap full. |
| 0925 | Begin LHe transfer @ MB = 24.1% |
| 0945 | Start 4He pump. Pump out 1K Pot in steps, alternating between V4a and the 1K Pot speedivalve. Pot started at 0.37 bar, then fell each cycle to 0.18/0.10/0.06/0.03 bar. Pot temperature dipped each time to as low as 3.4 K, then settles at 3.9 K. Needle valve is still closed. Sorb, MC, fridge pressure all fall. |
| 1000 | MC(Cernox)/Sorb/1K Pot = 5.6/4.8/3.9 K, G1/G2 = 443/404 mbar |
| 1005 | Open 1K Pot needle valve → 10°. 1K Pot → 3.1 K / 3.2 mbar |
| 1010 | Open 1K Pot needle valve → 20°. 1K Pot → 2.8 K / 5.0 mbar Open 1K Pot needle valve → 30°. 1K Pot → 2.6 K / 10 mbar MC starts falling very quickly, 5.3→4.1 K |
| 1015 | Open 1K Pot needle valve → 40°. 1K Pot → 2.3 K / 19 mbar |
| 1020 | MC(Cernox)/Sorb/1K Pot = 3.1/4.0(min?)/2.2 K, G1/G2 = 319/301 mbar. MC and fridge pressure falling. Turbo on IVC = 0.74 nbar |
| 1055 | MC(Cernox)/Sorb/1K Pot = 2.1/4.0(min?)/1.5 K, G1/G2 = 58/57 mbar. MC and fridge pressure falling more slowly now. Turbo on IVC = 0.86 nbar |
| 1055 | 1K Pot = 1.47 K / 5.5 mbar. Open 1K Pot needle valve → 50°. 1K Pot → 1.5 K / 7 mbar Open 1K Pot needle valve → 60°. 1K Pot → 1.55 K / 11 mbar |
| 1105 | Spontaneous jump in 1K Pot → 1.7 K / 100 mbar |
| 1150 | MC(Cernox) = 1.89 K, G1/G2 = 49/42 mbar. 1K Pot = 1.69 K / 75 mbar |
| 1157 | Close V3 and V9, leaving 42 mbar in the dump. |
| 1200 | Start circulation through Trap 2. V6 → 12.8%. Condenser peaks at 94 mbar. Tower falls to 1.82 K. Small response in 1K Pot |
| 1205 | V6 → 13.2%. Condenser peaks at 115 mbar. |
| 1210 | 1K Pot falls to 1.66 K / 45 mbar |
| 1213 | V6 → 13.4%. Condenser peaks at 118 mbar. Tower |
| 1216 | V6 → 13.6%. Condenser peaks at 139 mbar. Increase Lakeshore resistance range, Tower = 1.33 K and falling. P1 falls within range. P1 = 12 mbar |
| 1222 | V6 → 14.0%. Condenser peaks at 120 mbar. Tower → 1.07 K, Still → 5.0 mbar |
| 1226 | V6 → 14.4%. Condenser flattens at 124 mbar. Switch bask to tower thermometer. Tower → 1.02 K, Still → 3.0 mbar |
| 1230 | V6 → 15.0%. Condenser flat at 126 mbar. Tower → 862 mK, Still → 1.6 mbar |
| 1231 | 1K Pot has been flat at 1.66 K / 40 mbar |
| 1236 | V6 → 100%. Condenser flat at 129 mbar. Tower → 511 mK, Still → 0.24 mbar |
| 1250 | Tower → 85 mK, thermometer goes out of Lakeshore range again. |
| 1308 | Tower/MC/Coldplate = 40.4/33.5/182 mK, Still = 1.25±0.1 K / 0.085 mbar, G1/G2 = 78/81 mbar, 1K Pot = 1.66 K / 40±5 mbar. [image not archived: cool.svg] |
| 1323 | Purge E-box bag with a blast of N2 gas, then start slow flow of N2 gas. |
| 1324 | Tower = 36.9 mK and falling, Still = 0.095 mbar |
| 1331 | Open V14 to let the remaining mix out of the dump and into circulation. P1 peaks at 60 mbar, tower peaks at 87 mK |
| 1341 | Tower = 53 mK and cooling, Still = 3.0 mbar and falling |
| 1345 | Tower fell to 46.6 mK, then bounced up a little bit. P2 = 1.6 mbar |
| 1356 | P2 = 0.85 mbar, close V14 |
| 1415 | Tower = 36.3 mK, Still = 0.110 mbar, G1/G2 = 77/79 mbar, 1K Pot = 1.67 K / 45 mbar |
| 1430 | Plug cables into HV box. Causes a temperature spike, Tower → 38.5 mK then cools again. Plug in DCRCs. Start DAQ programs. Tower temperature spikes to 220 mK, then starts cooling again. |
| 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) | |
| 1445 | Tower = 37.8 mK and cooling. |
| 1445 | Zap SQUIDs on DCRCs 1&3. This seems to have failed: no temperature change, and at the end two of the DAQ programs switched themselves off. DCRC6 was enabled by mistake, it's not plugged in. Change ODB then restart DAQ programs. |
| 1455 | Zap SQUIDs on DCRCs 1&3. |
| 1505 | Tower = 37.0 mK, can see pulses on all channels! |
| 1508 | Start 30 min mini-bake using flashandflash tool. |
| 1555 | Tower = 45.6 mK and falling |
| 1600 | Fill LN2 cold trap bath |
| 1630 | Start HV scan sequence of 60-minute background data series at HV = 0,20,40,60 V, Driver Gains = 2x, QET biases = (280/260/305)/(140/295/300) uA, Front-End Gains = 10, 1000 initial randoms, trigger on DCRC3pB/C/D threshold = 8/16/16, 30 s flashing then waiting 30 min after each series, 15% prebias for 5min, using sequencer script HVscan-0_20_40_60-15_5PreBias-30Flash-30wait-60data.msl |
| 1632 | 1K pot = 1.66 K / 40 mbar |
| 1800 | At HV = 19.6 V, Vtest = 17 mV ⇒ Vdet = 12.8. Turn up N2 purge gas slightly, retape purge bag. test resistor voltage begins to fall slowly. |
| 1810 | Vtest = 13.3 mV and falling slowly. |
| 1822 | HV = 19.6 V, Vtest = 4.30 mV, Vdet = 17.9 V |
| 2303 | Start HV scan sequence of 60-minute background data series at HV = 0,20,40,60 V, Driver Gains = 2x, QET biases = (280/260/305)/(140/295/300) uA, Front-End Gains = 10, 1000 initial randoms, trigger on DCRC3pB/C/D threshold = 8/16/16, 30 s flashing then waiting 30 min after each series, 15% prebias for 5min, using sequencer script HVscan-0_20_40_60-15_5PreBias-30Flash-30wait-60data.msl |