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| | Current configuration: DIB1/2/3 → 100MHz filter/none/none → DCRC55/33/50. No bake, no source. |
| 0900 | Tower at 32.5 mK overnight, somewhat elevated, plus occasional excursions on the order of +1 mK. Looks a bit like a Bad State. Most phonon channels railed. After unrailing all channels, temperature falls back to base. |
| 0913 | Fill LN2 cold trap Dewar |
| 0935 | MC/Tower/Coldplate = 25.3/31.0/145 mK, Still = 0 mW / 0.11 mbar / 1.10 K, G1/G2 = 205/200 mbar, 1K Pot = 1.67 K / 13 mbar, Main bath = 67.0% |
The plan: measure IbIs on DIB3→DCRC50 with the 100MHz filter. This will allow a comparison with the no-filter and 3.2MHz filter cases.
| 0945 | Retake IbIs on DIB3→nofilter→DCRC50 pA (since the first time it looked anomalous). Settings for Output Gain / Frontend Gain / Driver Offset = 1 / 1 / 0. |
| 1004 | Return DIB3pA settings to standard values |
| 1035 | Look at pulse shapes on DIB3 to see if they are improved after we put the 100MHz filter on. |
| DIB3→nofilter→DCRC50, other DCRCs running normally |
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| DIB3→nofilter→DCRC50, other DCRCs' SQUIDs grounded |
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Basic observation: pA mediocre, pB decent, pC and pD poor on DIB3→nofilter→DCRC50, and turning off other DCRC pulses doesn't help.
| 1055 | Remove 100MHz filter from DIB1→DCRC55 and put it on DIB3→DCRC50. Power up boards, zap SQUIDs. Had to increase QET bias on DIB3pC&pD to see pulses. |
| 1145 | Take IbIs data on DIB3→100MHz→DCRC50. Analysis shows that the effect is similar to the 3.2MHz filter though slightly less strong. QET biases calculated for the 3.2MHz filter should work for the 100MHz filter too. |
| 1453 | Look at DIB3→DCRC50 pulse shapes, now with 100MHz filter |
| DIB3→100MHzfilter→DCRC50, other DCRCs running normally |
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| DIB3→100MHzfilter→DCRC50, other DCRCs' SQUIDs grounded |
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Basic observation: DIB3→DCRC50 pulses definitely improved by adding 100MHz filter. Having other DCRCs' phonons on may degrade DIB3 pulses a little.
| 1532 | Mini-bake: flash until temperature plateaus, then stop. |
| 1612 | Apply -4/+4 V. Set DIB3 QET biases as in the no-filter case except DIB3pC/pD = 70,109 μA. |
| 1613 | Start bkg data run. |
| 1631 | Stop data, 0/0 V. Flash 30 seconds. |
| 1650 | Adjust QET biases of DIB3pC/pD to 80,106 μA, the 3.2MHz values. (I'd intended pA and pB to be reset, too - MF) |
| 1651 | Noise that looked characteristic of lack of timing link present - wr 3c 0 fixed it for some reason. |
| 1654 | Apply -4/+4 V. Start bkg data run. |
| 1711 | Stop data. |
| 1729 | Fill LN2 trap full. |
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