2020/10/26 (Monday)
- Lab in-person: Ruiren
- 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. Lead/poly shield erected (4 lead walls, 2 poly walls). |
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| 1100 | Figured out the wiring for the endstops. The accessory board behind the HV box has three wires leading to a breakout panel (labeled SP, originally built for the slide potentiometer position detector that didn't work). The Near Endstop (+y direction) is connected to the Blue wire. The Far Endstop (-y direction) is connected to the White+Blue-stripe wire. That's the one we are interested in now. To test whether we are in contact, we should measure the resistance between that wire and analog ground. We can connect to analog ground via DCRC1or4's DSub shell, or from the HV shell maybe. |
| Later: verified that the White+Blue wire (Far Endstop) is connected to the Breakout Box side panel (labeled SP) at Pin1. The Blue wire (Near Endstop) is Pin2. Pin3 is not connected to anything. | |
| 1200 | Tower thermometer is around 85 mK, do a few IbIs on DCRC1pD, apparent detector temperature is around 59 mK. |
| 1207 | Start a 60 min series at HV = -10V, drifting 0.0230 V/s, no prebias, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = set automatically to track temperature, 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(10,0.023,3600,0,0) Use QETbias_update.c, function sequence_update_QETbiases(60,30,0,0.0294,56.54) |
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| 1207 | Vtest = -0.09 mV shortly after drift begins. Drift starts at -11.2 V. 0.32% HV loss. |
| Tower thermometer wandered between 85.0 and 85.6 mK during series. | |
| 1308 | Vtest = -0.29 mV at end of drift. Final HV = -93.4 V. 0.12% HV loss. |
| 1338 | Ruiren enters lab |
| 1338 | transfer lN2 into cold trap dewar |
| 1340 | Tower/MC/Coldplate = 86.4/31.8/196 mK, Still = 1.50 K / 0.120 mbar / 0 mW, G1/G2= 234/205 mbar, 1K Pot = 1.62 K / 18±2 mbar. |
| 1350 | Check resistance between HV ground and Pin1/2(Far/Near endstops): 0.36/0.12 nS |
| On Arduino web editor “rd dwell” returns 40 ms, good. | |
| 1400 | Move source -4×6 steps with 4 minute pause after each move, mvNwait -4 240 6 This should move the source to y = -41.407 mm warm (-41.250 mm cold, after correction for differential contraction). This should be 0.155 mm short of the endstop. |
| Resistance between endstops and ground remains essentially open (<1 nS) | |
| 1426 | Move source -4×1 step, mv -4. Should move source to -41.473 warm, -41.316 cold. Should be 0.089 mm short of the endstop. Resistances to Pin1 and Pin2 are still open. |
| 1430 | Move source -4×1 step, mv -4. Should move source to -41.540 warm, -41.382 cold. Should be 0.023 mm short of the endstop. Resistances to Pin1 and Pin2 are still open. |
| 1434 | Move source -4×1 step, mv -4. Should move source to -41.606 warm, -41.448 cold. Should overshoot the endstop by 0.043 mm. But resistances to Pin1 and Pin2 are still open. |
| 1438 | Move source -4×1 step, mv -4. Should move source to -41.672 warm, -41.514 cold. Should overshoot the endstop by 0.109 mm. But resistances to Pin1 and Pin2 are still open. |
| 1442 | Move source -4×1 step, mv -4. Should move source to -41.738 warm, -41.580 cold. Should overshoot the endstop by 0.175 mm. But resistances to Pin1 and Pin2 are still open. |
| 1447 | Move source -4×1 step, mv -4. Should move source to -41.804 warm, -41.646 cold. Should overshoot the endstop by 0.241 mm. But resistances to Pin1 and Pin2 are still open. |
| 1450 | Ruiren leaves lab |
| Temperature pattern doesn't look any different for any of these moves. | |
| We'll stop for now. It could be that in its upside-down orientation c/w Run71, the source mover carriage behaves a little differently. If it has a tilt one way or the other, it could hit the endstop sooner or later than expected. | |
| 2017 | MB = 55.8% |