2012/10/08
| 0950 | Filled LN2 cold trap. |
|---|---|
| 1000 | G2 seems to be gradually increasing over time. Two days ago it was at 52 mbar and today it's at 67 mbar. G1 is staying constant at 55 mbar. |
| 1044 | After talking to Jianjie, suspicion of cold trap was confirmed. This will have to be cleaned today, probably. |
| 1046 | Begin LHe transfer (7.6%) |
| Zapped DCRC 31 once. | |
| 1104 | Temperature is decreasing slightly… this isn't a fluctuation. Possibly a symptom of the cold trap being blocked? |
| Trying to tune channel B on DCRC 31, and it's wacky again. Why do the boards need to be zapped so often? | |
| 1108 | It seems like the pressures in both cold traps are dropping slightly. Very slightly. |
| 1137 | End LHe transfer (88.3%). |
| 1208 | Board 31 is not looking correct… it's as if the zapping has minute effect. Turning on FET heater to make sure charge supply is working. Will zap again after. |
| 1234 | Turned off FET heater for DCRC 31. It got up to 60.06 mK. Having turned it off, there seems to be a small leftover effect of temperature increasing. Regardless, I expected teh temperature to raise more than this and more quickly than it had. |
| 1400 | G1 and G2 rising again. Will try to tune DCRC32 first and then pump mixture to dump. |
| 1428 | DCRC 32 not looking great either. Also, accidentally sent a test signal down the wrong line when writing to a different channel - caused output gain to jump to >= 7. Noted that pressure in G1 and G2 jumped quickly to 77, 89 respectively. They are currently reducing. Mixing chamber temperature also increased. It's still increasing. I'm waiting to see if this will decrease as G1 and G2 decreases. |
| 1434 | Mixing chamber temperature is starting to drop. |
| 1622 | Changed DCRC_ZeroPhonon.vi value from 1002→1032. |
| Going to clean cold traps. Close V6, V1, V13A. | |
| 1629 | Open V9, V5, V12B. Pumping mixture to dump. |
| 1730 | Stop 1K pot. Close all valves on the IGH. Turn off He-4 pump. |
| 1736 | Open pathway to N2 cold traps. Turned on He-4 pump. Pulled out N2 cold traps. |
| 1749 | G1 rose to 43 mbar before starting to decrease. |
| 2005 | Stopped cleaning out cold traps after 2 rounds. Pumping out now for an hour. |
| 2108 | Stop pumping on cold traps. Filled LN2 cold trap. Turn off all valves on IGH. Return N2 cold traps to spots. Note that the styrofoam in the dewar broke off and is floating at the bottom of the dewar, thus not letting the cold traps sit in the dewar quite properly. |
| Start 1 K pot. | |
| Begin circulation by opening V1, V13A, and V12A. Opening V6 gradually. | |
| 2155 | Opened V6 all the way. |
| 2216 | Temperature is below 100 mK. The rate of decrease is slowing slightly. Really hoping it goes back to 60 mK. Leaving for the night. |
