| | Setup: iZIP mode, DIB1/2/3 → cables → 3.2 MHz filters → DCRC55/33/50 |
| | Taking Y-88 data overnight. But I think something went wrong… MIDAS page won't load, and no flashes in the last 12 hours… |
| | … the final data series recorded is 07160112_1511, so I guess MIDAS failed between 15:00 and 16:00 yesterday. I did notice the web interface was down yesterday before leaving but I didn't have time to investigate it. |
| 0835 | Tower/MC(H35)/MC sensor/Cold Plate = 31.8/25.9/38.9/151 mK, Still = 1.11K / 0.12 mbar, G1/G2 = 125/125 mbar, 1K Pot = 1.71 K / 19 mbar, Main bath = 20.8% |
| 0855 | Begin LHe transfer at 17.7% |
| 0900 | Fill LN2 cold trap Dewar. |
| 0941 | Finish LHe transfer at 85.7% |
| 1010 | Allison restarted the MIDAS interface. See MIDAS instructions… |
| 1015 | MIDAS restarted the sequence with a flash. I hit Stop Immediately to end the run, because I want to look at pulses. |
| 1025 | Looking at traces with Detector Testing GUI. Main bath = 86.4% so I expect strong Taconis noise. But I don't see very strong low-f noise in the channels (e.g. only 5 mVpp in DIB1pB). This is true with 0 V and also at +4V / -4V. However the tower is still cooling after the flash - maybe I should wait until it's back to base. |
| 1045 | Tower has cooled most of the way to base, currently 32.2 mK. Look at some low-f noise: |
| | DIB1pDa: 6 mVpp @ 220 Hz. May have gone up slightly with -4/+4 bias applied (or maybe just went up after a few minutes) to more like 10 mVpp. Disappeared completely after opening stopper and letting pressure out of bath. Replaced stopper and still saw no low-f sinusoidal noise after a minute or so. Then rebooted jiajin. |
| 1150 | Restarted jiajin. |
| 1255 | Main bath = 84.4%. Take another look at traces: very little low-f noise seen on DIB1 phonons, at zero volts and at -4/+4 V. Surprising. |
| 1320 | Start 20 hours of 30min 88-Y series at -4/+4V with FG=5/2/5, OG=3, with 1000 initial randoms, 1000 ending randoms, 30s flash and 25 minute cooldown before series. Trigger on DIB1 phA with threshold of 30ADC bins. |
| 1440 | Noticed that circulation pressures started steadily rising around 1200, from 125 mbar to around 210 mbar, where they seem to be plateauing. This is around when the DAQ was restarted, but there's no clear indication that that produced a problem. Maybe a trap impedance is forming. |
| 1448 | Temperature spike caused by switching cold traps. We were taking data at this time. Temp spiked to tower temperature of 63mK. |
| 1450 | Open V13B and V12B to bring Cold Trap 2 into circulation. Close V13A to pump out mixture from Cold Trap 1. Close V12A and Cold Trap 1 speedivalve. Open V11A and V8 to pump out remaining mixture in Cold Trap 1. P1 rises from 0.1mbar to ~200mbar, then begins dropping steadily. |
| | While pumping mixture out of Cold Trap 1, G1/G2 rise to ~221/209mbar. We'll see how it fares after we re-isolate Cold Trap 1. |
| 1630 | P1: 120ubar, which is the normal still pressure. Close V11A and V8 to isolate cold trap 1, and continue normal circulation. |
| 1735 | Fill LN2 cold trap full. |