2020/07/19 (Sunday)
- Lab in-person: Matt
- Virtual partner: Derek
| 0820 | Matt Fritts body temperature = 96.8 F |
|---|---|
| Status | Started circulation yesterday. Beginning Run 73 cooldown. |
| 0700 | MB 29.8% |
| 0820 | MC(H35) = 31.9 mK, G1/G2= 76/85 mbar, 1K Pot = 1.72 K / 75±8 mbar. |
| Note: G2>G1, which is not normal. Maybe there is contamination in LN2 Trap 2, and it should be cleaned. Currently Trap 1 is warm and has not yet been pumped out from the last cryocleaning. | |
| 0900 | Matt arrives in lab. |
| 0916 | Begin LHe transfer @ MB = 26.2%. |
| Setup | Run 73. DIB 1/3/4 → Stripline 43/48/41 → Cable 3/1/2 → nothing/nothing/accessory_interposer → HV_Conn 1/3/2 → HV 1/2 → DCRCX(4)/DCRC55(1); DCRC33(2) → HV control. DCRCs off overnight. Lead/poly shield erected (4 lead walls, 2 poly walls). |
| 0935 | Tower/MC/Coldplate = 68.1/31.5/190 mK, Still = 1.42 K/ 0.090 mbar, G1/G2= 74/84 mbar, 1K Pot = 1.69 K / 60±3 mbar. Note: these were taken during LHe transfer. |
| 0950 | End LHe transfer @ MB = 90.8% |
| 1020 | Tower = 69.0 mK. Went up a bit after transfer, now falling. |
| 1020 | 1K Pot = 1.67 K / 40 mbar. It got jostled by the transfer, now it's a bit low… |
| 1020 | Open 1K Pot Needle Valve 40→50°. 1K Pot → 1.71 K / 100±10 mbar. |
| 1025 | Fill LN2 cold trap bath |
| 1030 | Try powering the DCRCs. DCRC33(2) was already on (the one that controls HV). DCRCX(4) powers up with a small increase in Tower temperature. But DCRC55(1) is not turning on - when I plug a POE cable into it, no lights come on. |
| 1035 | Try DCRC50(3) with miniBOB. It powers up. Maybe we'll have to switch to that one. I'll replaced DCRC55(1) with DCRC50(3). |
| Setup | Run 73. DIB 1/3/4 → Stripline 43/48/41 → Cable 3/1/2 → nothing/nothing/accessory_interposer → HV_Conn 1/3/2 → HV 1/2 → DCRCX(4)/DCRC50(3)-master; DCRC33(2) → HV control. DCRCs off overnight. Lead/poly shield erected (4 lead walls, 2 poly walls). |
| 1040 | Power DCRCs. |
| 1050 | MB = 89.7% |
| 1055 | Matt leaves lab for the day. |
| 1315 | Tower = 69.9 mK, Still = 0.095 mbar, G1/G2= 76/84 mbar, 1K Pot = 1.71 K / 70±8 mbar. |
| Tower temperature is drifting upward. Maybe boost the cooling with the still heater. | |
| 1320 | Turn on Still Heater → 5 mW. Still → 0.16 mbar. Circulation pressures rise. Tower temperature also rises, at least at first. |
| 1320 | Matt Fritts body temperature = 97.4 F |