2020/08/15 (Saturday)
- 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). |
|---|---|
| 0830 | Tower = 52.4 mK |
| QET bias table | |||
|---|---|---|---|
| Temperature range | |||
| 50.9 to 54.1 | 54.2 to 57.4 | 57.5 to 60.7 | |
| DCRC4pB | 320 | 310 | 300 |
| DCRC4pC | 370 | 360 | 350 |
| DCRC1pB | 360 | 360 | 350 |
| DCRC1pC | 420 | 410 | 400 |
| DCRC1pD | 420 | 410 | 400 |
| 0830 | Set QET biases to Column 1 values (highest settings) |
|---|---|
| 0836 | Start a 60 min series at HV = +75V, drifting 0.0301 V/s, 1min pause after rampup, 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_pos75V_1min_30p1mVps_multiloop10_60min.msl |
| 0833 | Tower = 52.4 mK |
| 0837 | Vtest = 4.8 mV shortly after drift begins. Drift appears to start at +76.2 V. 2.6% HV loss. Leakage much better than yesterday, apparently it took a while for the Ebox purge to push out the humid air. |
| 0943 | Vtest = 9.9 mV, HV = 183.6 V, drift ends. 2.2% HV loss, good. Lag ratio = 1.1ish. |
| 0943 | Tower = 51.9 mK. |
 |
| After this second, stronger Al flash, it still looks like the gain is suppressed for high-energy events |
| 1057 | Start a 15 min series 0V, 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 SimpleDataLoopNoFlash.msl |
|---|---|
| 1058 | Tower = 52.0 mK |
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| This newest 0V data should be essentially the same conditions as the old one. It seems clear that high-E gain is suppressed still. |
Digging deeper: making the above plots for individual channels, it turns out that pB and pD do NOT have suppressed gains - only pA, pC, and pF do. What those have in common is that the are all on DCRC1. So maybe this is entirely a DCRC1 problem. There is one other issue with DCRC1 - DCRC1pB has an abnormal offset. So maybe it needs to be powercycled.
| 1305 | Zach Williams body temp = 98.2 |
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| 1325 | Zach arrives at lab. |
| 1330 | Tower/MC/Coldplate = 51.1/37.6/189 mK, Still = 1.40 K / 0.12 mbar / 0 mW, G1/G2= 396/360 mbar, 1K Pot = 1.64 K / 26±2 mbar. |
| 1332 | MB = 62.1% |
| 1341 | Filled LN2 cold trap dewar. |
| 1344 | Zach leaves lab. |
| 1405 | Zach Williams body temp = 98.0 |