2020/10/09 (Friday)
- 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 off. Lead/poly shield erected (4 lead walls, 2 poly walls). |
|---|---|
| Status | Cooling after warmup to deal with clogged 1K Pot. Started 1K Pot and circulation yesterday. |
| 0815 | MB = 28.0%. Will hit 20% a little after 1:00 pm |
| 0915 | MC(H35) = 30.9 mK, Still = 0.130 mbar, G1/G2 = 224/219 mbar. 1K Pot = 35° / 1.70 K / 55±5 mbar |
| 1400 | Zach body temperature = 98.9 F |
| 1428 | Zach arrives at lab. |
| 1432 | Tower/MC/Coldplate = 72.1/30.6/166 mK, Still = 1.11 K / 0.120 mbar / 0 mW, G1/G2= 225/229 mbar, 1K Pot = 1.70 K / 55±5 mbar. |
| 1445 | Plug in DCRCs. Had to mess with the DCRC1 seating in the HV box plug to get it to start |
| 1455 | Restart MIDAS. Note: had to set DCRC2 to Rev C (3) instead of Rev C.1 (3.1). Start DAQ programs. Didn't work at first, tried disabling DCRC1, then it worked, tried enabling DCRC1 again, then it worked again. |
| 1455 | Zap DCRC1&4 SQUIDs. |
| 1456 | MB = 16.0% |
| 1502 | Begin LHe transfer @ MB = 16.0% |
| 1516 | Filled LN2 cold trap bath. |
| 1536 | Ended LHe transfer @ MB = 92.6% |
| 1552 | MB = 92.0% |
| 1600 | Zach leaves lab. |
| 1610 | Tower = 67.9 mK. Currently dropping at about 1.5 mK/hour |
| 1615 | Check channels with pulse viewer, all are alive |
| 1625 | Pulses were looking weak - I adjusted DCRC1pD QET bias down to 240 uA. Pulses are stronger there - that's still probably pretty high in the transition. Looking at IbIs measurements from Sep 21 and Sep 22: at 62 mK the minimum was 280, at 65 mK the minimum was 260. |
| 1640 | Other channels are also showing pulses except DCRC1pB, which seems unresponsive to QET bias changes. |
| 1640 | Tower = 67.7 mK. Looks flat now. |
| 1655 | Checked SQUID modulation on DCRC1pB - adjusted offset, but looks OK otherwise I think. Still unresponsive to QET bias changes. Not sure what to do, I guess try another zap. |
| 1655 | Tower has arced back up to 67.8 mK. |
| 1700 | Zap DCRC1&4 SQUIDs |
| 1715 | Tower has cooled back to 68.4 mK after the zap, still cooling but slowly. |
| 1740 | DCRC1pB still unresponsive to QET bias changes. Try connecting Signal Generator to QET on DCRC1pB - also unresponsive, definitely see the effect in pC and pD. This channel already had the strange behavior that IbIs goes flat above like 300 uA. So maybe the QET bias is now just stuck at 0. Maybe need to try swapping DCRCs as a test. Or just powercycle. |
| 1800 | Tower = 68.1 mK, reasonably flat |
| 1900 | Do IbIs at around 68 mK to find optimal QET biases. Target to dI/dP gain of around 5 /V |
| 1907 | Start a 60 min series at HV = 0V, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (0,120,175,0)/(0,0,190,230)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 |
| 1910 | Tower = 68.6 mK |
| 3 minutes into series, brief spike in temperature to 68.8 mK. Relaxes to 68.4 mK by 16 minutes. Then slow rise. | |
| 2007 | Tower = 68.5 mK. |
| 2201 | Start a 60 min series at HV = +100V, drifting 0.0274 V/s, prebias 15% for 2min, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (0,120,175,0)/(0,0,190,230)uA, Front-End Gains = (3/3/3)/(5/5/5) 1000 BOR & 5 Hz in-run randoms, trigger on DCRC1pD threshold = 8 Use RootSequencer.c, function drift_sequence(100,0.0274) |
| 2201 | Vtest = 3.0 mV shortly after drift begins. Drift appears to start at 105.9 V. 1.1% HV loss. |
| 2202 | Tower = 68.4 mK |
| 2302 | Tower = 68.4 mK. Temperature stayed pretty constant throughout series, shallow 1-period sine wave with amplitude not much greater than 0.1 mK |
| 2302 | Drift ends, no apparent lag. Vtest = 4.6 mV. HV at end of drift looks like 203.9 V, indicating 0.90% HV loss |