2020/11/04 (Wednesday)
- Lab in-person: Matt
- Virtual partner:
| 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. Lead/poly shield erected (4 lead walls, 2 poly walls). |
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| 0858 | MB = 33.7% |
| 0925 | Tower temperature fell overnight, currently 65 mK. See some pulses in DCRC1pB, but not in others, or only weak ones. DCRC1pD IbIs shows no transition, looks like it's in normal state. |
| 0950 | DCRC1pB IbIs is a little confusing but suggests that it is quite warm, transition seen at maybe 25 uA, but does show some infrequent pulses at e.g. 100 uA |
| 1000 | Now suddenly seeing pulses in all channels. DCRC1pB had fallen into s/c, now requires higher QET bias. |
| 1015 | DCRC1pD IbIs suggests detector temperature 69 mK with Tower thermometer around 64 mK |
| 1100 | DCRC1pC IbIs suggests detector temperature 69 mK with Tower thermometer around 63 mK |
| 1115 | DCRC1pB IbIs yields similar to above |
| 1125 | DCRC4 channels are still odd - DCRC4pB was seemingly showing a transition, but the slope of the normal part was very high implying very low Rnormal. And it dropped into s/c much sooner than expected. Shows good pulses if I set QET bias to expected value based on 69 mK implied by DCRC1 channels. DCRC4pC shows pulses too but very low amplitude. |
| 1135 | Try DCRC4pB IbIs again, with smaller step sizes. Implies detector temperature of 68.4 mK, if taken at face value. |
| 1140 | DCRC4pC still has the bizarre behavior that IbIs shows not transition region, but it shows pulses at 200 uA, and none at 0 uA. |
| 1147 | Start a 60 min series at HV = 0V, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (173,199,234,157,216), Front-End Gains = (3/3/3)/(5/5/5) 1000 BOR & 5 Hz in-run randoms, trigger on DCRC1pB/D threshold = 8/8 Use sequence SimpleDataLoopNoFlash.msl Not using QETbias_update.c |
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| Tower thermometer wandered between 63.1 and 63.5 mK during series |
| 1258 | MB = 27.7% |
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| 1305 | Matt Fritts body temperature = 97.2 °F |
| 1340 | Matt enters lab |
| 1345 | A lot of the strange detector behavior we are seeing occurred after we started the various source mover tests. As a troubleshooting check, disconnect the cables meant to measure the endstop resistance and the waveform output to the motor. Also turn off the motor driver power and unplug the Arduino. Watching DCRC3pC and the tower temperature while doing this - no noticeable change. |
| 1445 | DCRC1pD/C/B IbIs suggest 68.5/68.4/68.7 mK detector temperature (Tower thermometer around 63 mK) |
| 1445 | DCRC4pB IbIs suggests 67.9 mK detector temperature, with the same confusing behavior - IbIs is “stretched”, making Rnormal seem to be only 25 mOhm (s/b around 90). DCRC4pC is even more confusing. |
| Let's try swapping out DCRC4 | |
| 1455 | Remove DCRC4, replace with DCRC3. Zap SQUIDs. |
| 1500 | Fill LN2 cold trap bath |
| 1515 | Channels all seem to be in normal state except DCRC1pB showing some pulses. Then, suddenly all channels fall into transition. Then they look normal again… |
| 1530 | Zap SQUIDS again |
| 1550 | Pulses seen in all channels again. Do high-bias IbIs just to get Rnormal. DCRC1pD/C/B Rnormal = 103/107/77 mOhm. DCRC3pB/C Rnormal = 25/13 mOhm. |
| so: the HV1 phonon channels are still just as weird after swapping DCRCs. The issue then is probably at the SQUET, or maybe the stripline connection. Still may be something to do with helium in IVC. | |
| let's move the source back from near the endstop. | |
| 1605 | Plub in Arduino, set driver power to 8.0 V. Double-click Ardunio Bridge on desktop - causes temperature spike. Set Dwell to 50 ms. |
| 1612 | Move source with “mvNwait +4 240 13”. This should move it to y = -41.010 mm warm, -40.855 mm cold. I think this is right at the pB inner edge. |
| 1630 | Matt leaves lab. |
| 1858 | MB = 17.3% |
| 1940 | Another quick look at DCRC3pB IbIs, again appears that Rnormal is only 25 mOhm. |