2020/08/10 (Monday)
- Lab in-person: Zach
- Virtual partner: Matt
| 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). |
|---|---|
| 0740 | MB = 32.9% |
| 0815 | Tower = 53.6 mK |
| Here's the table I made for setting QET bias, with new empirical temperature ranges. |
| QET bias table | ||||
|---|---|---|---|---|
| Temperature range | ||||
| 51 to at least 54 | ? | ? | 56 to at least 58 | |
| 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 |
| 0820 | Reset QET biases to Column 1 values |
|---|---|
| Let's try prebias, see if the noise is any different. Write a sequence for +40V drifted 26.9 mV/s with 15% 2-minute prebias. This is a little different from Nick's original sequence in that the target bias at the beginning of the drift is adjusted to account for the prebias wait. So in this case the drift begins at 40V+(26.9mV/s*120s)=43.23V. HVdrift_pos40V_pre15-2min_26p9mVps_multiloop10_60min.msl |
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| 0846 | Start a 60 min series at HV = +40V, drifting 0.0269 V/s, 2 min 15% 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_pos40V_pre15-2min_26p9mVps_multiloop10_60min.msl |
| 0845 | Tower = 53.4 mK |
| 0848 | Vtest = 2.2 mV shortly after drift begins. Drift appears to start at +42.8 V. |
| 0953 | Vtest = 5.6 mV, HV = 139.3 V, drift ends. Lag ratio = 1.12. |
| 0953 | Tower = 53.0 mK. |
 |
| The Luke gain is significantly lower than the last series. Is that because of the different sequence w/prebiasing, or because the temperature and QET biases were different? hard to say. |
| 1025 | Zach Williams body temperature = 98.6 |
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| 1045 | Zach arrives at lab. |
| 1055 | Tower/MC/Coldplate = 54.1/39.4/190 mK, Still = 1.42 K / 0.12 mbar / 0 mW, G1/G2= 405/372 mbar, 1K Pot = 1.64 K / 26±2 mbar. |
| 1118 | MB = 25.8% |
| 1123 | Started LHe transfer @ MB = 25.8% |
| 1129 | Started LN2 transfer, turned on still heater to 4.0 mW, P1 rose to 0.16 mbar. |
| 1137 | Ended LN2 transfer. |
| 1157 | Ended LHe transfer @ MB = 88.7% |
| 1230 | Zach leaves lab |
| 1300 | Zach Williams body temperature = 98.9 |
| 1705 | Tower = 57.0 mK |
| 1705 | Set QET biases to match 4th column of table above. NOTE: DCRC1 was at the higher Col1 values, but DCRC4 was at the lower - should maybe check to see if last series was done at correct QET biases |
| 1715 | Start a 60 min series at HV = +40V, drifting 0.0269 V/s, 2 min 15% 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_pre15-2min_26p9mVps_multiloop10_60min.msl |
| 1711 | Tower = 56.9 mK |
| 1715 | Vtest = 1.5 mV shortly after drift begins. Drift appears to start at +42.6 V. |
| 1821 | Vtest = 3.8 mV, HV = 139.2 V, drift ends. Lag ratio = 1.10. |
| 1821 | Tower = 56.3 mK. |
 |
| This prebiased data is similar to yesterday's not-prebiased data (this is a little lower). Compare with the prebiased data taken earlier today, when it was cooler and QET biases were higher; that one had significantly lower gain. |
| 1940 | Estimate that for +50V data we want 29.0 mV/s nominal drift. Write a sequence (without prebiasing) to do this. HVdrift_pos50V_29p0mVps_multiloop10_nopre_60min.msl |
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| 2040 | Tower = 55.7 mK. Perform quick IbIs on DCRC1pD - looks like it's shifted from the 51-mK case by 10 uA. That suggests using the 2nd column QET biases in the table. |
| 2055 | Start a 60 min series at HV = +50V, drifting 0.0290 V/s, no prebias, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (0,310,360,0)/(0,360,410,410) 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_pos50V_29p0mVps_multiloop10_nopre_60min.msl |
| 2055 | Tower = 55.6 mK |
| 2055 | Vtest = 1.9 mV shortly after drift begins. Drift appears to start at +49.4 V. |
| 2201 | Vtest = 3.9 mV, HV = 153.8 V, drift ends. Lag ratio = 1.10. |
| 2201 | Tower = 55.0 mK. |
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| Estimating that drift should be wait no, needs to be decreased to 27.5 mV/s |