| 0030 | Pump out exchange gas at 8 K. |
| | Helium transfer complete. Helium liquid level 92.7%. |
| | Fill N2 cold trap full. |
| 1330 | Mixing chamber temperature 5.4 K. Looks good; no sign of any leak. Start condensing mixture. |
| 1600 | Mixture condensed relatively slowly. Mixing chamber temperature 3.4 K. Start circulating mixture. |
| 1700 | Stop automated circulating procedure and run manually. Bleed mixture from dump into nitrogen cold trap through valve V14. |
| 1730 | Tower temperature has dropped below 100 mK. Stop bleeding mixture. We're ready to take data! |
| 2200 | Encountered a big problem. Plugged DCRC33 into flexible side coax and Qi and Qo signals saturated when 15 V power supply to FET was turned on. Switched board with DCRC32. Saw a decent PSD, and no amount of hammering seemed to have any effect. Connected DCRC33 to vacuum side coax, cycled the power and set the timing link: PSDs were fine on vacuum side coax; but Qi & Qo signals on flexible side coax saturated. Turned on FET heater for 5 minutes, broke timing link, nothing worked. Electrical check with breakout box shows no problems with FET heater. It's a bit of mystery. Email sent around to ask for suggestions. |