2021/09/14 (Tuesday)
- Lab in-personnel: Giulia and Matt
| 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/ |
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| Position of Am source: y = 0.0 mm | |
| 0840 | Tower/MC/Coldplate = 158.9/34.7/192.5 mK, Still = 1.39 K / 0.070 mbar / 0 mW, G1/G2= 289.3/271.2 mbar, 1K Pot = 1.56 K / 10±1 mbar. MB = 72.9%. |
| 0844 | Fill LN2 cold trap bath |
| 0846 | At 10kHz noise in DCRC3qI/qO/DCRC1qI/qO = 10/2.8/2.7/36 8e-6. This is q3/q1/q4/q2 At 3kHz (peak) noise in DCRC3qI/qO/DCRC1qI/qO = 80/21/32/360 e-6. |
| Noise is slightly higher than yesterday. | |
| 1026 | Start 45 min series of -10V/0V, then +10/0V (bias applied after 60 sec, then switch after 20 minutes), with 1000 beginning randoms, trigger threshold 70/35/30/250 on DCRC3qI/qO/DCRC1qI/qO, 5Hz in-run randoms, with 1.6384 ms pulses (8192 length) and 400 us prepulse (500 length). Use Sequencer script r74_6bias_takeandflash_dcrcbias.msl. This flashes for 30 seconds at end of series. |
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| 07210914_1026 | |
| If we want to try temperatures warmer than 1.2 K we probably need to stop circulation. | |
| 1155 | Close V6 completely. This stops circulation, so dilution cooling and still cooling will stop. Mixture will expand into the still side. |
| 1215 | Tower = 0.5 K and rising. G1/G2 = 150 mbar and falling. Still pressure rising, now off-scale. |
| 1310 | Tower = 0.95 K, still rising, slowly leveling - looks like it might level around 1.2 or higher. G1/G2 = 50 mbar and falling. |
| 1420 | Tower = 1.1 K, rising 0.08 K/hour, leveling off. |
| 1420 | Turn on MC heater → 200 uW |
| 1455 | Tower = 1.25 K, rising 0.23 K/hour. |
| 1455 | Increase MC heater → 500 uW |
| 1535 | Tower = 1.5 K, rising 0.36 K/hour. |
| 1535 | Turn off MC heater. We'll see if it levels off. |
| 1540 | Tower = 1.52 K, level |
| 1545 | Start 45 min series of +10/0V data (bias applied after 60 sec), at elevated temperature, with 1000 beginning randoms, trigger threshold 80/35/30/250 on DCRC3qI/qO/DCRC1qI/qO, 5Hz in-run randoms, with 1.6384 ms pulses (8192 length) and 400 us prepulse (500 length). Use Sequencer script r74_takeandflash_dcrcbias.msl. This flashes for 30 seconds at end of series. |
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| 07210914_1545 |