2020/09/07 (Monday)
- Lab in-person: Matt
- Virtual partner: Michael, Zach
| 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). |
|---|---|
| 0605 | Tower = 54.6 mK, MC Heater = 2 uW |
| 0605 | Turn off MC Heater. Tower settles to 49.8 mK. |
| 1248 | MB = 22.1% |
| 1255 | Matt Fritts body temperature = 97.7 F |
Notes on source mover:
- In Run 71, moving in + steps moved the source in the +y direction. That's toward the motor. With the current payload (see Feb 11) toward-the-motor is also in the +y direction.
- The -y direction is toward pD, away from pC, parallel to (dead) pE
- In Run 71 we moved 4 steps then paused 4 minutes. That's 1 step/min; with 48 steps/turn and 32 turns/inch, that's 0.9921875 mm/hour (without correcting for thermal contraction).
- First blocker is between -4.59 mm and -7.19 mm
| 1335 | Matt arrives at lab. |
|---|---|
| 1340 | Tower/MC/Coldplate = 49.8/31.8/196 mK, Still = 1.51 K / 0.095 mbar / 0 mW, G1/G2= 278/258 mbar, 1K Pot = 1.69 K / 45±2 mbar. |
| 1350 | Log into Arduino account, open Web Editor. Try plugging Arduino board into fridge computer and select Monitor on web interface - it does not see the board, no connection. Turn on GwINSTEK power supply… Tower temperature shoots up to 1.5 K! Turn off power to board, Tower cooling again. |
| 1400 | Now I remember, you have to double-click Arduino-Create-Bridge Shortcut on desktop first. After doing that and reloading the page once or twice, we now have communication with the board again. |
| 1400 | Set dwell on source mover board to 40 ms |
| 1405 | Turn on GwINSTEK source mover power supply again, turn on power output, dial up to 8.0 V. Tower temperature does not go up this time, it's at 75 mK and falling. |
| 1415 | Fill LN2 cold trap bath |
| 1415 | Tower = 65 mK and cooling. Let's try moving the source with mvNwait. |
| 1420 | Attempt to move source -4×4 steps with 4 minute pause after each move, mvNwait -4 240 4 |
| After first move Tower spikes to 1.0 K, then cools. | |
| 1429 | Begin LHe transfer @ MB = 19.4% |
| 1440 | Arduino mvNwait seems to be stuck after the first move. After 20 minutes Tower is still cooling, no subsequent spike. Arduino monitor says “1/4: move -4 steps, wait 240 seconds.” indicating it is still on the first move, hasn't progressed. |
| Actual move: Move source -4*1 steps | |
| 1445 | Turn off source mover power supply, then unplug Arduino board. |
| 1450 | Unplug source mover wires from driver board, plug in external motor, fire up Arduino and power supply. Try mvNwait -4 10 4. Works fine. In consultation with Nick, he thinks the problem is that an input of 240 seconds causes an overflow (it's converted to ms, which is 240000, which may be too large for unsigned int) |
| 1455 | Checking Nick's theory: try mvNwait -24 32 2. It works. Try mvNwait -24 33 2. It doesn't work, it hangs. Nick says that that's just past the overflow for the unsigned int. (15 bits.) |
| 1505 | End LHe transfer @ MB = 92.6% |
| 1515 | Nick walked us through modifying the firmware, so that when seconds gets converted to ms it gets cast as unsigned long. Test on external motor, seems to work for 33 seconds. Now we can put in delays as long as 9 hours. |
| 1525 | Unplug Arduino, plug the source mover wires back into driver, plug in Arduino, set Dwell to 40 ms, turn on Source Mover Power Supply to 8.0 V. Looks good, no temperature spike. |
| Let's try just 2 moves while I finish up with logging the LHe transfer. | |
| 1535 | Move source -4×2 steps with 4 minute pause after each move, mvNwait -4 240 2 |
| After first move Tower spikes to 0.95 K then cools. | |
| 1539 | Second move occurs on schedule. Tower temperature fell to 0.71 K before spiking second time to 1.07 K. |
| 1550 | MB = 92.1% |
| 1605 | Move source -4×48 steps with 4 minute pause after each move, mvNwait -4 240 48 |
| With the other -4*3 moves done today, the source should end up at y = -3.969 mm (without correcting for thermal contraction). Should take 3hr12min, so end at 18:17. | |
| 1610 | Matt leaves lab |
| 1805 | The sequence of moves continues, temperature min/max is 0.8/1.1 K. |
| 2005 | Tower = 73 mK and cooling |
| 2005 | Check phonon channels: 2 are OK and show pulses. The other 3 are railed. |
| 2010 | Zap SQUIDs |
| 2020 | All 5 phonon channels are working. Tower = 68 mK and cooling. |
| 2140 | Tower = 53.8 mK and cooling |
| 2230 | Tower = 51.2 mK, still cooling |
| 2232 | Start a 60 min series at 0V, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (0,320,370,0)/(0,360,420,410)uA, Front-End Gains = (3/3/3)/(5/5/5) 1000 BOR & 5 Hz in-run randoms, trigger on DCRC1pD threshold = 8 Use sequence SimpleDataLoopNoFlash.msl |
| 2322 | Tower = 50.0 mK. Temperature fell steadily throughout series |
| 2333 | Start a 60 min series at 0V, CDMS detector: Driver Gains = 1x, DCRC4/1 QET biases = (0,320,370,0)/(0,360,420,410)uA, Front-End Gains = (3/3/3)/(5/5/5) 1000 BOR & 5 Hz in-run randoms, trigger on DCRC1pD threshold = 8 Use sequence SimpleDataLoopNoFlash.msl |
| 2433 | Tower = 49.3 mK. Temperature fell steadily throughout series |
 |
| It does not look like the gain fell after the move, even though we did not do a hot Al flash |
 |  |
| pD versus pC delay and transition indicate that the source has moved (this is for the 60keV line) | |
 |
| Also noise doesn't seem adversely affected even though we have not disconnected the source mover. |