2021/07/10 (Saturday)
- Lab in-personnel: Michael
| Status | Run 74 in progress. First cooldown after IVC rebuild. |
|---|---|
| Tower thermometer is reading high, probably this is a thermometer problem and the actual temperature is much lower. High noise in some of the charge channels. | |
| Setup: DIB1/2+acc → SL 41/43 → 3.2 MHz filters → cables 2/3 → nothing/Source_mover_board+HV_diverter_board → DCRC50(3)/55(1). Kepco 40V supplye → HV BNC. No lead/poly shield. Currently DCRC55(1) is disconnected and off, Cable 3 plugged into source mover board only. | |
| 1030 | Fill LN2 cold trap bath. |
| 1042 | Tower/MC/Coldplate = 100/37.5/190 mK, Still = 1.38 K / 0.075 mbar / 0 mW, G1/G2= 248/228 mbar, 1K Pot = 1.63 K / 20±1 mbar. MB = 68.1% |
| Yesterday we had a problem with the source mover board which we fixed, but we aren't sure where the source was. We moved it back toward the endstop the same number of reliable moves that we'd moved away from it. | |
| 1055 | Check “far” endstop to chassis - no connection |
| 1055 | Do mvNwait -4steps×3 times, 35 second wait, with dwell = 40 and power = 6.8 V. This is enough to hit the endstop. That means a lot of the “bad” moves yesterday actually worked. Kinda strange. |
| 1100 | Do mv +4 twice. This is enough to break contact with endstop. |
| OK, now we're going to move back to the center, under the assumption that the source is currently at the far endstop. | |
| 1125 | Reestablish connection with Arduino without turning off driver power, because no one is in the lab now. This causes the familiar temperature spike, to about 100 mK. |
| 1127 | Do mvNwait +4steps×626 times, 40 second wait, with dwell = 40 and power = 6.8 V. (Around 5.93 mm/hour) This is a total distance of 41.28 mm and will take almost 7 hours, ending around 6:24 pm After 16 minutes the mean MC temperature flattens around 180 mK, varying by about 2 mK. Around 40 minutes in the mean MC temperature settles to 175 mK and stays there throughout, with a diversion up to 178 mK toward the end. Condenser rose from 260 to 290 mbar during sequenced and stayed there. Sequence ends at 6:29 pm, MC starts cooling |
| If we are correct that the good endstop is the far endstop, then the source should be back at y=0 mm |