2016/08/19 (Friday)
| Setup: iZIP mode, DIB1/2/3 → 3.2 MHz filters → cables → DCRC55(1)/33(2)/50(3), Tower has been cooled below Al transition with mu-metal shield 56.8 cm below standard position | |
| DCRCs powered overnight. Pumping on IVC with turbo pump overnight. Baked detector for 12 hours (ended at 5:10). Tower = 0.4 K during bake. | |
| 0815 | Tower/MC/Coldplate = 39.3/42(? unstable)/151* mK, Still = 1.23* K / 95 μbar, G1/G2 = 210/195 mbar, 1K Pot = 1.51 K / 5.0 mbar, MB = 66.6%. When bridge excitation reduced from 63 to 20 μV, MC temperature reads 32.0 mK. * above were measured at 20 μV excitation. This excitation is too low for the U02844 tower thermometer. Boiloff rate: bad. It's almost exactly at the “fast mode” rate. Yesterday's pressure releases at 8min and 30min after fill to 91.6% didn't work apparently. |
| 0825 | Fill LN2 cold trap bath |
| 0825 | Confused to find that DIB2 FET power is off. I think that was true yesterday morning too. But we were baking overnight and the last rd 30 on the DIB2 telnet session showed 0800. What turned off the FET power?? |
| 0830 | Using ODB, turn on DCRC2 FET/LED power: Tower spikes to 130 mK then falls. Flash for 30 seconds: Tower spikes to 260 mK. After it starts to cool again, turn off DIB2 FET/LED power. |
| 0840 | Release pressure from main bath. Don't know whether it matters at this point. |
| 0855 | Adjust driver offsets on phonon channels to get all the baselines near -0.7 |
| 0856 | With DIB2 FETs turned off on the ODB, Manually start one 30min background series at -6/+6 V with FG=5/2/5, OG=8/3/8, with 1000 initial randoms, 1000 ending randoms. Trigger on DIB1 phA with threshold of 30ADC bins, with 150 us pileup cut window. |
| 0927 | Stop data. Wait for randoms to finish, then set biases to zero. |
| 0930 | Using ODB, turn on DCRC2 FET/LED power: Tower spikes to 135 mK then falls. Flash for 30 seconds: Tower spikes to 260 mK. After it starts to cool again, turn off DIB2 FET/LED power. |
| 0950 | Check phonon channels, all look OK |
| 0957 | With DIB2 FETs turned off on the ODB, Manually start one 30min background series at -6/+6 V with FG=5/2/5, OG=8/3/8, with 1000 initial randoms, 1000 ending randoms. Trigger on DIB1 phA with threshold of 30ADC bins, with 150 us pileup cut window. |
| 1027 | Stop data. Wait for randoms to finish, then set biases to zero. Using ODB, turn off DCRC2 FET/LED power. |
| 1057 | With DIB2 FETs turned off on the ODB, Start two sets of 30min background series at -6/+6 V using the updated Flash&Take script with FG=5/2/5, OG=8/3/8, with 1000 initial randoms, 1000 ending randoms. Trigger on DIB1 phA with threshold of 30ADC bins, with 150 us pileup cut window. |
| 1100 | Stop series after flash, during cooldown because the 15V power is still enabled during the cooldown, and will only turn off once the cooldown is over, which means that the temperature spike caused by turning off the FET will come right before the sequencer starts taking data. We'll have to modify this. |
| 1119 | Flash&Take script updated, so now we can Start two sets of 30min background series at -6/+6 V using the updated Flash&Take script with FG=5/2/5, OG=8/3/8, with 1000 initial randoms, 1000 ending randoms. Trigger on DIB1 phA with threshold of 30ADC bins, with 150 us pileup cut window. |
| 1350 | Finish experimenting with /Equipment/Tower01/Settings/DCRC1/LED/ConnectLEDVoltagesToPhononADCs setting in ODB. Took a test series of data to analyze the pulse train created by the LEDs. |
| 1354 | Begin closing v6 |
| 1400 | IVC pumping pressure at 0.86 nbar. Isolate turbo pump for warmup. Close 13b, turn off 3He pump, turn on MC heater to 1mW. |
| 1405 | Main bath = 55.6%. Still boiling off in “fast mode”. |
| 1440 | Tower temp = 3.3K. IVC pressure = 220nbar. Commence turbopumping on IVC. |
| 1450 | Turn off MC heater |
| 1513 | Commence LHe transfer (51.8%). |
| 1515 | Both the tower temperature and G1/G2 have stabilized. Turn on He3 pump and open V13B to begin cooldown procedure with mu-metal shield in standard position. |
| 1600 | End LHe transfer (93.2%). |
| 1600 | V6 = 13.6%, Tower = 1.5 K, G1/G2 = 250 mbar, Still (P1) falls into readable range. |
| 1606 | Let pressure out of main bath. |
| 1638 | Let pressure out of main bath. |
| 1655 | Open V6 to 100%. Tower temp = 560mK and dropping. P1 = 240ubar and dropping. |
| Fill LN2 cold trap full. | |
| 1705 | Release pressure from main bath. |
| 1735 | Tower temp = 44mK. All pulses look good. Adjust Driver Offsets to set them around -0.7V baseline. |
| 1737 | Commence overnight bake of 12 hours. |