| Status | Run 74 in progress. |
| | Setup: DIB1/2+acc → SL 41/43 → 3.2 MHz filters → cables 2/3 → nothing/motor_board+HV_board → DCRC50(3)/55(1). No lead/poly shield. |
| 1255 | MB = 24.9% |
| 1340 | Tower = 124 mK. Still kinda unstable, has varied from 114 to 124 mK since last night. |
| | Still seeing extreme noise in DCRC1qI. I guess it's not gonna fix itself. |
| 1500 | Ruiren enters lab |
| 1504 | Tower/MC/Coldplate = 126/30.4/189 mK, Still = 1.46 K / 0.130 mbar / 0 mW, G1/G2= 209/183 mbar, 1K Pot = 1.67 K / 36±2 mbar. |
| 1600 | We've been trying a number of troubleshooting efforts to discover the source of the DCRC noise issues. Between power cycling, removing the diverter boards, and swapping DCRC's we have determined the issue is most likely on the cold end of the electronics, NOT the warm end (the noise followed the detector channels rather than the DCRC channel). Maybe it's due to helium films in the IVC. We may need to try a partial warmup. [image not archived: sad.svg] |
| 1600 | Flash detector for 30 seconds. This did not seem to help the noise. |
| 1623 | Start LHe transfer @ MB = 18.9% |
| 1652 | End LHe transfer @ MB = 89.8% |
| 1700 | Fill LN2 cold trap bath |
| 1710 | Ruiren leaves lab |
| | Some problems with the transfer: the connection between the two pieces was a little leaky this time. After disconnecting, Ruiren saw that the o-ring had disappeared. He couldn't find it - we'll have to look for it or get a replacement. Also the gasket for the cap to the cryostat piece is broken, should try to make a new one. Just a circle of some tough rubber sheet of some sort. |
| 1925 | Tower has cooled a bit, now 101 mK |
| 1925 | The noise in DCRC1qI is not so bad now. Noise in the channels is not great… let's do some estimates |
| | At 10kHz noise in DCRC3qI/qO/DCRC1qI/qO = 200/16/560/50 e-6. This is pretty bad still. But maybe a little better. Let's try a longer flash, maybe the last one helped a little. |
| 1940 | Start 5-minute flash (minibake) |
| 2000 | MB = 88.4% |