2020/08/09 (Sunday)
- Lab in-person: Matt
- Virtual partner: Ash and Griffin
| Setup | Run 73. DIB 1/3/4 → Stripline 43/48/41 → pi-filters 1/2/3 → Cable 3/1/2 → nothing/nothing/accessory_interposer → HV_Conn 1/3/2 → HV 1/2 → DCRCX(4)/DCRC55(1)-master; DCRC33(2) → HV control. DCRCs on overnight. Lead/poly shield erected (4 lead walls, 2 poly walls). |
|---|---|
| 0920 | Matt Fritts body temperature = 97.1 °F |
| 0840 | MB = 67.4% |
| 0930 | Tower = 54.0 mK |
| Tower is cooler than last night. Last night after IbIs I made the table below to estimate how the QET biases should be adjusted as the temperature changes. It looks like we are in the second column now… |
| QET bias table | ||||
|---|---|---|---|---|
| Temperature range | ||||
| 50.7-52.5 | 52.5-54.2 | 54.2-55.9 | 55.9-57.8 | |
| DCRC4pB | 320 | 310 | 300 | 290 |
| DCRC4pC | 370 | 360 | 350 | 340 |
| DCRC1pB | 360 | 360 | 350 | 350 |
| DCRC1pC | 420 | 410 | 400 | 390 |
| DCRC1pD | 420 | 410 | 400 | 390 |
| 0950 | Do a quick IbIs on DCRC1pD. It looks almost exactly the same as the Aug 3 IbIs, even though Tower is now 53.9 mK, then 51.9 mK. At any rate it seems we should go back to the 1st column settings. |
|---|---|
| 1000 | After relocking a couple channels, Tower temperature is now falling. I guess maybe the temperature was stuck kinda high because of some bad QET state? |
| 1045 | Tower has settled to 52.2 mK. Still falling slowly. |
| 1047 | Start a 60 min series at HV = +30V, drifting 0.0275 V/s, no prebias, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (0,320,370,0)/(0,360,420,420) uA, Front-End Gains = (3/3/3)/(5/5/5) 1000 BOR & 5 Hz in-run randoms, trigger on DCRC1pD threshold = 8 Use sequence HVdrift_neg30V_33p0mVps_multiloop10_nopre_60min.msl |
| 1050 | Tower = 52.2 mK |
| 1050 | Vtest = 1.8 mV shortly after drift begins. Drift appears to start at +29.5 V. |
| 1153 | Vtest = 5.6 mV, HV = 127.2 V, drift ends. Lag ratio = 1.10. |
| 1153 | Tower = 51.9 mK |
 |
| This plot suggests we run +40V at 29.6 mV/s, -40V at 36.1 mV/s, assuming 1.10 lag ratio |
| 1435 | Matt enters lab |
|---|---|
| 1440 | Tower/MC/Coldplate = 51.8/35.0/189 mK, Still = 1.42 K / 0.12 mbar / 2 mW, G1/G2= 407/377 mbar, 1K Pot = 1.65 K / 28±2 mbar. |
| 1450 | Fill LN2 cold trap bath |
| 1515 | LN2 fill lowered circulation pressures and caused Tower to rise above 56 mK. Try turning on Still Heater to 3 mW. Temperature comes down a little, we'll see how it goes. |
| 1525 | Tower started rising again, now > 58 mK, circulation pressures rising - we'll see if they settle, then maybe turn heater off again…. |
| 1530 | Matt leaves lab |
| 1620 | Having trouble getting the temperature down again. Currently above 59 mK, Still Heater off at the moment. |
| 1625 | Matt Fritts body temperature = 97.6 °F |
| 1715 | Perform quick IbIs on DCRC1pD at 58 mK. Looks almost exactly the same as yesterday at 57 mK. So we could maybe take data with the lower (Column 4) QET biases and it would be sorta comparable. |
| 1720 | Write sequence for +40V data drifted at 29.6 mV/s. HVdrift_pos40V_29p6mVps_multiloop10_nopre_60min.msl |
| 1720 | Reset QET biases to Column 4 values in table above. Channels all look fine. |
| 1723 | Start a 60 min series at HV = +40V, drifting 0.0296 V/s, no prebias, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (0,290,340,0)/(0,350,390,390) uA, Front-End Gains = (3/3/3)/(5/5/5) 1000 BOR & 5 Hz in-run randoms, trigger on DCRC1pD threshold = 8 Use sequence HVdrift_neg40V_29p6mVps_multiloop10_nopre_60min.msl |
| 1724 | Tower = 57.9 mK |
| 1725 | Vtest = 2.7 mV shortly after drift begins. Drift appears to start at +39.5 V. |
| 1830 | Vtest = 6.5 mV, HV = 145.9 V, drift ends. Lag ratio = 1.12. |
| 1830 | Tower = 57.4 mK |
 |
| Drift is too fast, should maybe be reduced to 26.9 mV/s That's actually lower than I did the last +30V one. But that one was actually a little too fast too. |
| 2040 | MB = 49.5% |
|---|---|
| 2055 | Write new sequence for +40V drifted at 26.9 mV/s. HVdrift_pos40V_26p9mVps_multiloop10_nopre_60min.msl |
| 2100 | Start a 60 min series at HV = +40V, drifting 0.0269 V/s, no prebias, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (0,290,340,0)/(0,350,390,390) uA, Front-End Gains = (3/3/3)/(5/5/5) 1000 BOR & 5 Hz in-run randoms, trigger on DCRC1pD threshold = 8 Use sequence HVdrift_pos40V_26p9mVps_multiloop10_nopre_60min.msl |
| 2100 | Tower = 57.0 mK |
| 2101 | Vtest = 2.4 mV shortly after drift begins. Drift appears to start at +39.5 V. |
| 2206 | Vtest = 5.7 mV, HV = 135.9 V, drift ends. Lag ratio = 1.10. |
| 2206 | Tower = 56.7 mK. Note that it fell as low as 56.3 then bounced back up |
