2022/01/21 (Friday)
- Lab in-personnel: Matt and Giulia
| 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. Am Source y = 30.03 mm |
| 1115 | Goldman/Tower/MC(H35)/Coldplate = 40.9/74.4/33.4/180 mK, Still = 1.43 K / 0.110 mbar / 0 mW, G1/G2= 259.1/229 mbar, 1K Pot = 1.59 K / 15±1 mbar, MB = 67.3%. |
| 1124 | Fill LN2 cold trap bath |
| Results from first IbIs runs in December | ||
|---|---|---|
| channel | T [mK] | Ib for 1.0 uV |
| DCRC1pA | 56.2 | 241.4 |
| DCRC1pB | 53.4 | 319.2 |
| DCRC1pC | 53.4 | 275.1 |
| DCRC1pD | 53.4 | 175.2 |
| DCRC3pA | 51.1 | 162.5 |
| DCRC3pB | 51.1 | 164.7 |
| DCRC3pC | 51.1 | 216.1 |
| DCRC3pD | 0 | |
| DCRC4pA | 51.1 | 201.2 |
| DCRC4pB | 51.1 | 145.5 |
| DCRC4pC | 50.3 | 265.2 |
| DCRC4pD | 50.3 | 185.6 |
| 1300 | Finish mini-IbIs on a few channels to get a data point at this low temperature |
|---|---|
| 1305 | Goldman = 41.0 mK. Set QET biases to target dP/dI=1.0 uV and adjust driver offsets so baselines ~ -0.9 V |
| 1309 | Start 0V data series, 50 min long, with 1000 initial randoms, no in-run randoms, trigger on DCRC3pB threshold 10. Start series with the Start Button. |
| 1314 | Goldman = 41.1 mK. Readjust QET biases. |
| 1410 | Establish communication with Arduino. This causes a temperature spike because I'm working remotely so I didn't turn off the GwINSTEK power supply output. Goldman spikes to 0.40 K then cools. |
| 1410 | Set Dwell to 40 ms |
| 1418 | Do mvNwait +4steps×152 times, 40 second wait, with dwell = 40 and power = 6.8 V. (Around 5.93 mm/hour) This sequence will take 1hr41min20sec and will move the source a total distance of 9.96 mm ending at y = 20.01 mm. Should end at 3:59 pm. Tower temperature averages around 0.51 K, with 40-second oscillations as well as the familiar 1-rotation oscillation. |
| 1650 | Goldman = 57 mK and cooling |
| Gonna take the opportunity to measure more transition temperatures, at least ballpark values. | |
| 1655 | Set all QET biases to 0 |
| 1700 | Set up DCRC1 for Tc tests. Set Test Signal to 12 mVpp / 200 Hz. Trigger on test signal. Connect test signal to QETs. Modulation is ~10-12 mVpp except DCRC1pB which is ~3 Vpp. Is that one normal? Goldman = 51.2 mK. |
| 1710 | Goldman = 49.9 mK |
| 1711 | Turn on DCRC1 LEDs with rep rate reduced from 5000 to 500. Turn off LEDs after 3 minutes. Goldman peaked at 1.28 K. |
| 1715 | Goldman = 400 mK and cooling. Modulation in pA/B/C/D = 2.5/1.5/2.0/2.9 mV |
| 1730 | Goldman = 100 mK and cooling. Modulation in pA/B/C/D = 2.5/1.7/2.0/2.8 mV |
| 1745 | DCRC1pC transitioned by 77 mK, probably somewhere between 77-80. DCRC1pA at 76 mK. DCRC1pD @ 69 mK. |
| 1745 | At 56 mK DCRC1pB doesn't seem to have transitioned. This is an oddball channel, first because its IbIs flattens at high biases (which is something to do with the SQUET) and second because it requires the highest QET biases to hold in transition, though it's not really an outlier. With the other three channels it looks like QET bias has a positive correlation to Tc, which I guess makes sense. So pB is strange in that respect. |
| 1800 | Goldman = 49 mK and cooling. Still no evident transition in DCRC1pB. |
| 1805 | Goldman = 48 mK and cooling. Still no evident transition in DCRC1pB. Of course we know it shows pulses at this temperature… |
| 1805 | Turn off test signal, disconnect QETs from test signal, stop triggering on test signal and start random triggers. |
| 1810 | Set all QET biases to somewhere in transition. All channels show pulses. So somehow we just couldn't see pB transition. |