2017/02/09 (Thursday)
| Setup: DIB1/3/4 → 3.2 MHz filters → cables → DCRC55(1)/33(2)/50(3) | |
| 0845 | Tower/MC/Coldplate = 35.7/35.1/199 mK, Still = 1.31 K / 0.110 mbar, G1/G2 = 181/160 mbar, 1K Pot = 1.692 K / 28 mbar, Main bath = 37.8%. Boil off rate: |
| Fill LN2 cold trap bath. | |
| 0851 | DCRCs 1,2,3 were left running overnight, but all seem to still be operating (i.e. no stuck output) |
| 100Hz seen on at least 1 channel of each DCRC. The noise looks like a triangle wave. The last frequency used on the DCRC1 test signal was 100 Hz… This noise was apparently caused by the DCRC3 test signal being on. Changing the DCRC3 test signal frequency changed the noise frequency. Turning the DCRC3 test signal off killed the noise. |
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| 1105 | Start detailed IbIs study on DIB1pA with Front-end Gain = 10. Took data in normal and transition region first, then superconducting and back up into transition - no hysteresis seen, pops right back from s/c to transition at the same point. |
| 1528 | Complete IbIs study of DCRC1pA with FEG=50. Forest of high frequency oscillations seen at all QET biases. Otherwise, IbIs curve matched earlier FEG=10 measurements. |
| Inverted | Non-inverted |
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| 1550 | Looked at PSD of DIB3pB (which we thought had only a single such oscillation frequency). But found that a whole forest of frequencies come in and move depending on FEG in a complicated way. This merits further study, but not right now… |
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| 1551 | Start LHe transfer (MB = 26.6%). |
| 1552 | Check DIB4 cable and gender changer by swapping it with DIB1's. i.e. swap cable 1 and cable 3 along with their gender changers and pi filters. |
| 1559 | DCRC3pB now responds to changes in QET bias. Can also now see pulses on DCRC3pB (Side2 pF)! |
| Setup: DIB1/3/4 → 3.2 MHz filters 3/2/1 → cable 3/2/1 →gender changer 3/2/1 → DCRC55(1)/33(2)/50(3) |
| Channel Roll Call | |||
|---|---|---|---|
| DIB | Channel | Responds to QET bias changes | Notes |
| DIB1PA | Side1 pE | yes | good pulses |
| DIB1PB | Side1 pB | yes | good pulses |
| DIB1PC | Side1 pD | yes | good pulses |
| DIB1PD | Side2 pE | yes | good pulses |
| DIB3PA | Side2 pB | no | |
| DIB3PB | Side2 pA | yes | good pulses |
| DIB3PC | Side1 pA | yes | good pulses |
| DIB3PD | n/c | no | |
| DIB4PA | Side2 pC | no | |
| DIB4PB | Side2 pF | yes | good pulses |
| DIB4PC | Side1 pC | yes | good pulses |
| DIB4PD | Side1 pF | yes | good pulses |
| 1622 | Try putting cable 1 on DIB3 now. |
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| 1625 | Finish LHe transfer (MB = 93.7%) |
| Setup: DIB1/3/4 → 3.2 MHz filters 3/1/2 → cable 3/1/2 →gender changer 3/1/2 → DCRC55(1)/33(2)/50(3) | |
| 1636 | DIB3PA is still unresponsive to QET bias changes. It seems that the cable swapping only helped DIB4PB |
| 1640 | While looking at DIB4pB again with DCRC3, DCRC3 went flatline again. Damn. Try powercycling it. |
| 1645 | Release pressure from MB. |
| 1650 | Repowered DCRC3 this time using a POE box (one of the white ones). It was working at first. But after a couple of minutes it flatlined again. |
| Temperature of recovery meter during LHe transfer |
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| The probe on the room thermometer (“OUT”) was taped to the housing of the recovery meter during the transfer. At the lowest temperature this implies that the meter is underestimating the recovery by 5%, or more if the gas itself is colder. |
| 1705 | Try powering DCRCX (with no DIB plugged in), it is still flatline (although at -1.25 V, not at an intermediated value). Try powercycling DCRC3 again, still flatline (although this also at -1.25 V). Seems dead again. |
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| 1710 | Unpower DCRC3. Let it cool off and think about its behavior. |
| 1725 | Release pressure from main bath. |
| Fill LN2 cold trap bath. |