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2018/04/13 (Friday)

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Status: Tower installed up to 600mK rod. Mixture cleaned several times. Cryostat vacuum jacket pumped out.
1120 Check pressure in warm LN2 Trap 1: 3.3 mbar. Pump out with scroll pump.
1125 Check pressure in warm LN2 Trap 2: 4.7 mbar. Pump out with scroll pump.
Cryocleaning log
date trap duration (minutes) contaminants removed (mbar)
Apr 6 1 70 9.5
Apr 6 2 70 6.6
Apr 6 1 70 11.0
Apr 6-7 2 overnight, no circ, dump exposed to trap 12.8
Apr 7-9 1 overnight, no circ, pump exposed to trap 6.8
Apr 9 2 70 8.9
Apr 9 1 60 9.0
Apr 10 2 90 10.5
Apr 10 1 70 8.5
Apr 10 2 75 6.6
Apr 10 1 70 1.9
Apr 11 2 75 2.7
Apr 11 1 75 14.4
Apr 11 2 70 4.5
Apr 11 1 70 6.4
Apr 12 2 70 4.7
Apr 12 1 135 3.3
Tower installation
1300 Bottom stripline heatsink installed, 4K stage installed
1300 Electrical check on DIB3: among SQUID Biases, Feedback loops, and QET loops, a couple of channels read around 1 MΩ. Squeezing the stripline/SQUET connection can fix them, but others go bad. Something wrong with the pins on this SQUET? (ZC-74)
1450 Try a different SQUET on the same stripline #41. All the phonon-related stuff looks OK.
1500 Try the same thing but with the SQUET plugged into a slot on the tower. All phonon-related stuff OK. So it definitely seems like problems related to connections on the SQUET ZC-74.
1525 Unplug ZC-74 from tower, then plug it into Stripline 41. Similar problems. Try squeezing the connection tighter - most of the readings get better. SQUID B a little unstable.
should be noted that we only have one Side1 phonon channel connected to on DIB3, that's DIB3pC.
1555 Plug ZC-74 back into tower, check again. Now all phonon related readings look OK. (The ones that are the least reliable are not pC, so we should be OK.)
1600 Finish DIB3 electrical check. All looks ok. q0 Feedback-Drain/Source reads 1 nS, not a problem for this run. Also check continuity between QETs, qC-qB and qC-qA read 3.7 kOhm, this is through detector. Looks OK.
1625 Finish DIB1 electrical check. All ok. Also cross-channel checks show continuity.
1650 Finish DIB4 electrical check. All ok. Also cross-channel checks show continuity.
1740 Begin pumping out IVC with scroll pump
1755 Begin pumping out IVC with turbo pump

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