| | 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) (on/on/off) |
| 0900 | Tower = 34.6 mK, MB=35.3% |
| 0905 | Fill LN2 cold trap bath. LN2 storage Dewar needs a refill |
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| 0920 | Try IbIs with DIB1pB. Front-end gain 10, driver gain x1. Attempting a continuous curve from QETbias = 0 μA up through transition. But when the s/c part of the curve is taken from 0 to around 90 the baseline suddenly jumps downward by around 0.5 V. Tried relocking but the behavior happened again. Tried increasing front-end gain - on this channel, increasing front-end gain all the way to 100 does not seem to introduce new noise. But the jump in baseline happened again, this time between 40 and 60 μA settings. The shift persists as the QET bias is taken back down again. So maybe should try starting near transition then coming down from there. |
| 1015 | Notice that in transition, FEG=100 certainly does introduce high-frequency noise |
| 1045 | Tried starting at 135 μA and coming down, looked good, came back and tried to find transition point, but at some point when shifting back and forth between s/c and transition, another baseline jump, -1.5 V downward. Very annoying. This seems to be taking the necessary driver offset way near the bottom, so something seems wrong. |
| 1050 | Check SQUID modulation curve. It looked like the lockpoint was very close to the top of the curve. Readjusted DIB1pB SQUID lockpoint from -3.3 to -5. |
| 1145 | Finish IbIs on DIB1pB. Worked much better after adjusting SQUID. |
| 1428 | Finish IbIs on DIB1pC. Observed 350kHz amplifier oscillation with FEG=20 and QET bias <12uA. Above this bias, the oscillations disappeared. |
| 1444 | Tower/MC/Coldplate = 34.6/29.8/190 mK, Still = 1.23 K / 0.110 mbar, G1/G2 = 195.5/184.2 mbar, 1K Pot = 1.698 K / 30 mbar, Main bath = 26.3%. Boil off rate: faster than slow mode. |
| 1444 | After filling LN2 dewar, fill LN2 cold trap full. |
| 1500 | Start LHe transfer (MB = 25.6%). Also checking for leaks with leak detector. |
| 1544 | Finish LHe transfer (MB = 92.0%). |
| 1600 | Release pressure from MB. |
| 1648 | Re release pressure from MB. |
| 1755 | Complete DCRC1 PD IbIs. SQUID modulation curve looked fine before and after IbIs, but around 200uA ran into a SQUID jump that I couldn't get back from. Additionally, when entering transition from low bias region, found that this channel exhibited some hysteresis and needed to be snapped to a higher bias first. |