| | Current setup: iZIP mode, DIB1/2/3 → cables → 3.2 MHz filters → DCRC55/33/50. |
| | Overnight: no source, no data, no bake, DCRCs unpowered |
| 0945 | Fill LN cold trap Dewar |
| 0955 | Tower/MC(H35)/MC sensor/Cold Plate = 30.5/24.1/39.5/155 mK, Still = 1.33 K / 0.080 mbar, G1/G2 = 150 mbar, 1K Pot = 1.72 K / 22 mbar, Main bath = 19.0%. |
| 1020 | Powered up DCRCs and apply SQUID settings. No sign of the 80Hz noise on DCRC55 pB. Good news. |
| 1315 | Tightened almost all of the seals for the bath&recovery system, KF and the compression o-ring joints at fridge top. Did not tighten the screws for the top bath seal however. |
| 1330 | Commence LHe transfer (12.2%). |
| note | trying slower transfer than in recent months, back to Hassan's old standard. Target transfer rate is about +1%/minute. (In recent months it's been closer to 1.5-2.0%/minute.) Also will not fill too high: back to previous method of stopping pressurization at 85%, then ending transfer at 90%. |
| 1335 | Use Snoop to look for leaks in recovery system after transfer started. Checked transfer tube, top of fridge, tubing from fridge to recovery system - no leaks seen. It might be hard to see the bubbles from a leak in a KF joint since the o-ring is mostly hidden by the clamp. Didn't check the hard plastic tubing on the walls or near the meter. |
| 1450 | End LHe transer (90.6%). |
| note | This transfer came very close to the target of +1%/minute. The pressurization valve on the Dewar was modulated to keep the rate about right. This corresponded to a “chirp rate” at the wall meter of 10 chirps per 12-13 seconds (definitely a lot slower than during recent transfers). So that chirp rate is a good standard. |
| note | Transfers are slower at the beginning, so to get an overall rate of +1%/minute, the rate after the first part of the transfer should be closer to +1.1%/minute. |
| 1655 | Fill LN2 cold trap full. |