2021/12/29 (Wednesday)
- Lab in-personnel: Matt
| Status | Run 75 in progress |
|---|---|
| Setup | Tower Faces 5/3/2 → Cables 2/1/3 → nothing/diverter_board/nothing → DCRC55(1)/DCRC50(3)/DCRCx(4) Lead shield in place |
| 1015 | Goldman/Tower/MC(H35)/Coldplate = 49.5/87.3/38.8/213 mK, Still = 1.64±0.07 K / 0.130 mbar / 0 mW, G1/G2= 240/222 mbar, 1K Pot = 1.62 K / 19±1 mbar, MB = 36.4%. |
| 1025 | Fill LN2 cold trap bath |
| 1500 | Turn off power to Arduino, then plug Source Mover wires from diverter board into source mover breadboard. Consulted a photo from July 9. Diverter wires Orange/Brown/Red/Yellow connected to breadboard wires Purple/Gray/White/Black, which connect to red driver board in that order, Purple nearest to the end of the board. |
| 1528 | Begin LHe transfer @ MB = 28.6% |
| 1553 | End LHe transfer @ MB = 93.7% |
| 1635 | Preparing to test source mover. Referring to March 24 |
| 1640 | Doubleclick Arduino_Create_Bridge_shortcut on desktop and open arduino web editor page. Used “sign in with google” using my UMN account. Select Web Editor. Select Monitor. Enter “help” to see instructions. So far so good. |
| EXCEL spreadsheet on Fridge computer: Run75_source_mover.xlsx, using that to keep track of moves. | |
| 1645 | We'll try a move using the settings at the end of Run 74, referring to Aug 18. Set dwell = 40 Turn on GwINSTEK power and adjust to 6.8 V Haven't set up to monitor waveforms, we'll just trust that it's set up right and see if the temperature does what's expected. |
| 1656 | Do mvNwait +4steps×31 times, 40 second wait, with dwell = 40 and power = 6.8 V. (Around 5.93 mm/hour) This sequence will take 20min40sec and will move the source a total distance of 2.04 mm. Should end at 5:16 pm. After a few moves Goldman thermometer only rises to 0.2 K. Could it be that it responds too slowly? Switch to Tower thermometer. OK, after 5 moves Tower thermometer ~ 1.6 K, that looks right. |
| 1705 | Around move 13 Tower thermometer has started swinging in extremes: in the last move it swung from 1.3 K min to 4 K max. But fridge pressures aren't changing much so I doubt this is accurate. Switch back to Goldman thermometer: around 0.52 K. |
| 1715 | Goldman thermometer settled into a square-wave pattern. Minima between 0.4 and 0.45 K, maxima between 0.53 and 0.64 K. Oddly, the period is around 79 seconds, even though the the delay between moves is 40 seconds. |
| Condenser pressure rose from around 240 to around 250 mbar during move sequence. (It rose about the same amount during the LHe transfer.) | |
| 1720 | Move sequence is finished, tower is cooling. |
| 1806 | Goldman = 60 mK, 49 minutes after move sequence ends |
| 1927 | Goldman = 50.5 mK, 1 mK higher than pre-move base, 2hr7min after move sequence ends |
| 2000 | Goldman = 50.0 mK, 0.5 mK higher than pre-move base, 2hr43min after move sequence ends |