2021/12/23 (Thursday)
- Lab in-personnel: Matt, Himangshu
| Status | Run 75 in progress |
|---|---|
| Setup | Tower Faces 5/3/2 → Cables 2/1/3 → nothing/diverter_board/nothing → DCRC55(1)/DCRC50(3)/DCRCx(4) Lead shield in place, S wall partially complete |
| 1115 | Goldman/Tower/MC(H35)/Coldplate = 46.5/89.2/35.2/209 mK, Still = 1.71±0.04 K / 0.130 mbar / 0 mW, G1/G2= 199/198 mbar, 1K Pot = 1.63 K / 21±1 mbar, MB = 30.9%. |
| 1125 | Fill LN2 cold trap bath. |
| 1135 | Perform mini-IbIs on DCRC1pA. The QET bias had been set to 241 uA to target a dP/dI of 1.0 uV, based on IbIs data from a couple weeks ago when the fridge was warmer. IbIs now suggests a dP/dI of 0.77 uV. |
| 1156 | Start 0V data series, 29 min long, with 1000 initial randoms, no in-run randoms, trigger on DCRC3pB threshold 5. Start series with the Start Button. |
| We'll set up to measure some Tc's. First, let's turn all the QET biases to zero. We'll wait a bit to see if this causes a noticeable change in tower temperature. | |
| 1320 | Set all QET biases to 0. Before this they were at: DCRC1/3/4 = 241,319,275,184 / 163,165,216,0 / 201,145,265,186 |
| Side 2 channels seem to have lower Tc's so let's start with DCRC4 which has three Side2 channels. | |
| 1340 | Set up DCRC4 for Tc tests. Set Test Signal to 12 mVpp / 200 Hz. Trigger on test signal. Connecting test signal to QET seems to work on pB, pC, pD but not pA. Note that this is done with the SQUID tuning GUI - I don't know how to do it on the ODB. |
| 1410 | Watching DCRC4pB and pD mostly (pC seems to have higher Tc according to IbIs), start applying heat to MC. Start with 1 uW. Goldman = 46.4 mK before applying heat. |
| 1422 | MC = 5 uW, Goldman = 64.5 mK. No transitions seen yet |
| 1431 | MC = 22 uW, Goldman = 73.3 mK. pD transitioned was 66.5 mK. pB transition was 70.4-70.5 mK. |
| 1440 | MC = 30 uW, Goldman = 89 mK. pC transition was 78.1-81.9 mK. Start cooling now. |
| 1455 | MC = 0 uW, Goldman = 67 mK. All channels are back in s/c state. |
| DCRC4pB (Side2pA) | DCRC4pC (Side1pA) | DCRC4pD (Side2pD) | |
|---|---|---|---|
| Transition start, warming | 70.4 | 78.1 | 66.5 |
| Transition end, warming | 70.5 | 81.9 | 66.5 |
| Transition start, cooling | 74.8 | 85.9 | 73.6 |
| Transition end, cooling | 74.3 | 81.5 | ~73 |
| 1455 | Fill LN2 cold trap bath. |
|---|---|
| 1504 | Begin LHe transfer @ MB = 24.9% |
| 1520 | Restore transition QET biases on all 11 channels and adjust driver offsets to set baselines ~ -1.0 V |
| 1538 | End LHe transfer @ MB = 83.2% |