2022/01/04 (Tuesday)
- Lab in-personnel: Matt
| 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 = |
| 1305 | Goldman/Tower/MC(H35)/Coldplate = 48.0/84.0/38.0/210 mK, Still = 1.66±0.02 K / 0.120 mbar / 0 mW, G1/G2= 248/245 mbar, 1K Pot = 1.61 K / 18±1 mbar, MB = 29.3%. |
| Tower thermometer read wrong until I increased the excitation to 200 uV. Switched back to 63 uV after that. |
Some notes on recent data:
- We have data with source at y=0 and at 2 mm on either side
- It is not very clear from the data which direction is which, by partition or by timing. We seem less sensitive to position than in Run 73:
- Run 73 was Ge, this is Si. So events from source won't be as tightly clustered in detector
- This is Si, so you may expect more position sensitivity than Ge
- Run 73 was HV, this is 0V. That will likely make this data less resolved.
- There is a hint that + steps are moving the source in the - direction (toward near endstop, -y in detector coordinates). I thought I'd gotten it wired the same as in R74, which would be + steps in the + direction, but maybe not.
- Side2pD (DCRC4pD) had anomalously low amplitudes in yesterday's data. Not sure what's wrong. Is there trapped flux? pD is close to the motor, but Side1 is much closer than Side2, and Side1pD is fine.
- Yesterday I changed the QET biases three times during the series to compensate for the falling temperature. Looking at data it seems that this worked, the amplitudes stay constant with time.
| 1335 | Begin LHe transfer @ MB = 28.6% |
|---|---|
| 1340 | Fill LN2 cold trap bath |
| 1408 | End LHe transfer @ MB = 93.1% |
| Let's move the source further, with negative steps, whatever direction that is. We'll move to a position 10 mm from the center. That's not far enough to hit either endstop, and it won't be over a blocker. | |
| 1455 | Turn off output on GwINSTEK power supply. Establish communication with Arduino. Had to reload the Arduino Editor webpage then select COM4 in the dropdown then select Monitor. Turn GwINSTEK output back on. Do rd dwell - it's back at 15 ms, so I guess it reset itself. Set dwell to 40 ms. |
| 1501 | Do mvNwait -4steps×122 times, 40 second wait, with dwell = 40 and power = 6.8 V. (Around 5.93 mm/hour) This sequence will take 1hr21min20sec and will move the source a total distance of 8.04 mm. Should end at 4:22 pm. After about 20 moves temperature settles into pattern between 0.4 and 0.64 K. |
| 2105 | Zap SQUIDs on all 3 DCRCs |
| 2210 | Goldman = 48.6 mK. Adjust QET biases based on mini-IbIs trends versus temperature to target dP/dI = 1.0 uV on all channels. QET biases = 247/320.8/282.1/186.6/166.1/166.8/219.1/0/210.5/151.6/261.1/195.4 Adjust driver offsets so all baselines are around -0.9 to -1.0 V |
| 2218 | Start 0V data series, 38 min long, with 1000 initial randoms, no in-run randoms, trigger on DCRC3pB threshold 10. Start series with the Start Button. |
| 2023 | Goldman = 48.7 mK. Do an in-run QET bias adjustment. QET biases = 246.7/320.5/281.7/186.2/165.8/166.5/218.9/0/210.3/151.5/260.9/195.1 |
| 2055 | Goldman = 48.6 mK. Not bothering to readjust the QET biases, will stop series soon. |
| As in the last data series, Side2pD (DCRC4pD) had anomalously low amplitudes. |