2017/07/03 (Monday)
| Status | 4K. Pumping out IVC with turbo pump since Friday. Mixture is open to dump, pump (off), Trap 2, fridge. |
|---|---|
| 0840 | Lab = 22.2 C, 42% humidity |
| 0845 | MC(Tower)/Sorb/1K Pot = 5.02/8.1/6.25 K, Fridge(G1) = 593 mbar, MB = 72.4%. Turbo pressure = 2.2 μbar, IVC = 16 μbar. IVC pressure seems to be as low as in Run 62. |
| 0850 | Fill LN2 cold trap bath |
| 0850 | Pump Trap 2 contents to dump. We'll use Trap 1 for circulation. |
| 0900 | Connect 4He pump to 1K Pot pumping line, turn on pump, open the two valves connecting pump exhaust to recovery |
| 0905 | Open mixture to dump, pump (off), Trap 1, fridge. Trap 2 is empty. |
| 0905 | Open 1K Pot speedivalve. Mechanical gauge rises to about 1/3 bar. Open V4a (note that pumping lines had been evacuated). Didn't have 4He pump isolated so this pumps out quickly to 0.020 mbar. 1K Pot temperature falls to 4K but then rises again to 6.2 K. |
| 0910 | Open 1K Pot needle valve about 10 degrees. 1K Pot → 3.3 K / 3.2 mbar Open needle valve a few more degrees. 1K Pot → 3.1 K / 4.0 mbar Open needle valve a few more degrees. 1K Pot → 3.0 K / 4.5 mbar Open needle valve a few more degrees. 1K Pot → 2.7 K / 6.5 mbar, MC temperature falls to 3.5 K Open needle valve a few more degrees. 1K Pot → 2.6 K / 12.0 mbar Open needle valve a few more degrees. 1K Pot → 2.3 K / 19 mbar Open needle valve a few more degrees. 1K Pot → 1.9 K / 28 mbar |
| 0940 | Tower = 2.95 K, Fridge (G1/G2) = 280 mbar, both falling |
| 0950 | Tower = 2.52↓ K, Fridge (G1/G2) = 150↓ mbar, 1K Pot = 1.69 K / 26 mbar |
| 0955 | 1K Pot falling to around 20 mbar, open needle valve a few more degrees. |
| 1000 | Tower = 2.16↓ K, Fridge (G1/G2) = 75 mbar, 1K Pot = 1.66 K / 18 mbar, open needle valve a few more degrees. |
| 1005 | Coldplate/Still = 3.5/2.35 K |
| 1005 | 1K Pot spikes to 1.9 K, pressure off-scale. Temperature oscillates around 1.85 K, pressure still high |
| 1010 | Tower = 2.11 K, Fridge (G1/G2) = 62 mbar, both flat |
| 1015 | Close needle valve a bit, 1K Pot settles around 1.75 K / 60 mbar |
| 1020 | Tower/Coldplate/Still = 2.11/2.64/2.49 K, Fridge (G1/G2) = 60 mbar, 1K Pot = 1.75 K / 55 mbar |
| 1025 | Turn on 3He Pump. Close V9, keeping 58 mbar of mixture in dump. |
| 1025 | Start circulation through Trap 1, V6 = 13.0%. Condenser peaks at 68 mbar, Tower → 2.08 K and falling |
| 1030 | V6 → 13.3%. Condenser(G1) → 120 mbar (peak), Tower → 1.79 K (and falling). Coldplate/Still = 2.57/2.00 K |
| 1035 | V6 → 13.6%. Condenser(G1) → 184 mbar (peak), Tower → 1.52 K (and falling). Coldplate/Still = 1.94/1.59 K. 1K Pot = 1.74 K / 50 mbar. Still pressure falls into readable range. |
| 1045 | V6 → 14.0%. Condenser(G1) → 185 mbar (peak), Tower → 1.24 K (and falling). MC/Coldplate = 1.24/1.36 K, Still = 1.16 K / 4.0 mbar. |
| 1055 | V6 → 15.5%. Condenser(G1) → 129 mbar (climbing), Tower → 0.75 K (and falling). MC/Coldplate = 0.79/0.62 K, Still = 1.15 K / 0.70 mbar. |
| 1105 | Condenser(G1) flat at 134 mbar |
| 1110 | V6 → 100%. Condenser(G1) → 135 mbar (peak), Tower → 0.34 K (and falling). MC/Coldplate = 0.27/0.43 K, Still = 1.12 K / 0.12 mbar. |
| 1120 | Tower = 135 mK and falling. |
| 1130 | Tower = 90 mK and falling. Still = 0.09 mbar. Open V14 to bring in the rest of the mixture. Still peaks at 400 mbar then falls below 30 mbar. G1/G2 peak around 160 mbar then fall again. Tower temperature rises to 140 mK. |
| 1140 | Tower = 63.5 mK. Still = 1.5 mbar and falling (V14 still open) |
| 1150 | Tower = 47.7 mK. Still = 0.75 mbar. Close V14. G1/G2 = 85 mbar and rising slowly. |
| 1155 | Tower/MC/Coldplate = 36.8/36.8/179 mK, Still = 1.2 K / 0.060 mbar, G1/G2 = 89/87 mbar, 1K Pot = 1.74 K / 50 mbar. Still thermometer a little unstable |
| 1230 | Tower = 29.7 mK [image not archived: cool.svg] |
| 1250 | Tower/MC/Coldplate = 29.5/30.9/176 mK, Still = 1.2 K / 0.060 mbar, G1/G2 = 90/88 mbar, 1K Pot = 1.73 K / 50 mbar. |
| 1310 | Set DCRC1 SQUID settings so that they match the DIB1 SQUET from the last run, the last time we had 2-sided running. |
| 1315 | Plug DIB1 into DCRC1 and turn on DCRC1. Tower temperature spikes a couple of mK, then returns. |
| 1320 | Zap SQUIDs on DCRC1/DIB1. MC rises to 33.6 mK then falls again, Still pressure spikes then back to normal. |
| 1335 | Tried starting vnc session to view pulses but it isn't working… |
| 1345 | VNC authentication didn't work for Matt, had to have Allison do it. Don't know why. |
| 1400 | See first pulses! DIB1 pA, had to bring QET bias down to 45 uA to see strong pulses. 40 uA knocks it down into s/c. Rate seems pretty high, and pulses have much longer fall times than the recent HV detectors. Fall time around 1.3 ms. |
| 1430 | See pulses on DIB1 pA/pC (at 45/55 uA). pD has some “rain” dripping off traces, maybe due to the short to chassis. Tried tuning its SQUID. Can't see pulses, not sure if IbIs makes sense. On pB IbIs seems to make sense but channel appears to be normal all the way down to 0 uA. |
| 1435 | Set up to measure Tc in DIB1 pA and pC, the working channels. QET bias = 0, test signal 12 mVpp / 100 Hz connected to QET. |
| 1435 | Tower = 29.3 mK |
| 1455 | Finish Tc check on DIB1 pA/pC. Heated tower as high as 58 mK by applying up to 11 uW power to heater. While temperature rising, both seemed to go through full transition by 54 mK. Then while temperature falling we could see approximate beginning and end of transition. DIB1 pA (Side1 pD) : 53.8 - 54.0 mK DIB1 pC (Side1 pE) : 54.5 - 55.0 mK |
| SQUET ZC13 | SQUET ZC39 | SQUET ZC26 | ||||||
|---|---|---|---|---|---|---|---|---|
| Run 62 DIB1 = DCRC1 | Run 62 DIB3 = DCRC2 | Run 62 DIB4 = DCRC4 | ||||||
| chan | SQUID bias | Lockpoint | chan | SQUID bias | Lockpoint | chan | SQUID bias | Lockpoint |
| pA | -91.2 | -4.3 | pA | -54.0 | -1.8 | pA | -81.8 | -3.3 |
| pB | -78.8 | -3.3 | pB | -60.3 | -1.8 | pB | -78.3 | -2.9 |
| pC | -82.0 | -4.8 | pC | -46.3 | -2.0 | pC | -85.0 | -3.5 |
| pD | -85.2* | -2.7 | pD | 85.0 | 5.7 | pD | -85.0 | -5.7 |
| Run 63 DIB1 = DCRC1 | Run 63 DIB4 = DCRC2 | Run 63 DIB3 = DCRC4 | ||||||
| *today after SQUID tuning changed DIB1pD SQUID bias to -100 uA | ||||||||
| 1520 | Estimate event rate: 74 pulses in 0.5 seconds = 148 Hz. Compare with Run 62, had 89 Hz with no shield. Shield blocks out 65 Hz so we should be able to reduce the rate to 83 Hz. |
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| Setup: DIB1 → 3.2 MHz filters 1 → cable 1 → gender changer 1 → DCRC55(1) | |
| 1605 | Tower/MC/Coldplate = 29.2/30.8/175 mK, Still = 1.2 K / 0.060 mbar, G1/G2 = 91/88 mbar, 1K Pot = 1.73 K / 45 mbar. |
| 1615 | Fill LN2 cold trap bath |
| 1620 | Filling the LN2 trap bath brought Tower temp even lower, 29.0 mK. Impressive. |