| Setup | Run 73. DIB 1/3/4 → Stripline 43/48/41 → pi-filters 1/2/3 → Cable 3/1/2 → nothing/nothing/accessory_interposer → HV_Conn 1/3/2 → HV 1/2 → DCRCX(4)/DCRC55(1)-master; DCRC33(2) → HV control. DCRCs off. Lead/poly shield erected (4 lead walls, 2 poly walls). |
| Status | 1K Pot is not working. 1K Pot valves are open to MB. |
| 0855 | MB = 42.3%. Gonna take a while to boil that off today. |
| 0935 | MC(H35)/Sorb/1K Pot = 5.73/8.8/6.88 K. |
| 0940 | Matt Fritts body temperature = 96.8 F |
| 0940 | Turn on MC & Still Heaters → 20/30 mW |
| 1025 | Matt arrives in lab |
| 1030 | MC(H35)/Sorb/1K Pot = 11.1/12.0/>7 K. |
| 1030 | Turbo on IVC = 3 nbar. With Turbo valved out for 1 minute, IVC = 30 nbar |
| | With the 1K Pot a little warmer, we'll try throughput tests like yesterday. |
| 1045 | Perform a modified 1K Pot throughput test. With needle valve closed or open to different amounts, close V4a to stop pumping, then time how fast the pressure rises to the 2“ mark on the mechanical gauge. (Tap the gauge continuously to unstick the indicator.) Results: Needle valve = 0°/30°/60°/90° → rise time = 54.8/44.8/25.8/29.5 seconds. Slower than yesterday. 1K Pot dropped from >7 to 5.2 K during the tests, then rose again. Sorb dropped to a minimum of 6.7 K from about 12 K. |
| 1055 | Let about 10 ubar He into IVC, leave the valve partially open for a while - settles to 0.86 ubar after closing the valve. MC(H35) falls from 11.7→4.8 K. Sorb/1K Pot → 6.2/5.0 K. |
| 1055 | MB = 39.8% |
| 1100 | Isolate IVC then connect turbo pump manifold to cryostat vacuum jacket port, pump out line to port. |
| 1140 | Recovery = 17.3 cuft/hour |
| 1143 | Let 0.46 mbar He gas into vacuum manifold. Then open cryostat vacuum jacket valve to let this into the vacuum jacket. Vacuum Jacket → 12 ubar. Recovery meter speeds up. |
| 1150 | Recovery = 147 cuft/hour |
| 1155 | Recovery = 105 cuft/hour, 386601.7 cuft |
| 1155 | MB = 36.1% |
| 1200 | Recovery = 62 cuft/hour, 386606.8 cuft |
| 1205 | Recovery = 76 cuft/hour, 386613.2 cuft |
| 1210 | Recovery = 64 cuft/hour, 386618.5 cuft |
| 1215 | Recovery = 57 cuft/hour, 386623.3 cuft |
| 1255 | MB = 31.3%. Boiling off around 3X faster than normal. |
| 1300 | Recovery = 36 cuft/hour, 386654.5 cuft |
| 1315 | Cryostat vacuum jacket = 0.4 ubar. |
| | Boiloff is definitely slowing down, let's add another dose of gas to the CVJ. |
| 1316 | Let 0.63 mbar He gas into vacuum manifold. Then open cryostat vacuum jacket valve to let this into the vacuum jacket. Vacuum Jacket → 19 ubar. |
| 1325 | Recovery = 54 cuft/hour, 386669.9 cuft |
| 1330 | Recovery = 80 cuft/hour, 386676.5 cuft |
| 1335 | Recovery = 87 cuft/hour, 386683.8 cuft |
| 1340 | Recovery = 83 cuft/hour, 386690.8 cuft |
| 1345 | Cryostat vacuum jacket = 3.4 ubar. |
| 1345 | Let 1.0 mbar He gas into vacuum manifold. Then open cryostat vacuum jacket valve to let this into the vacuum jacket. Vacuum Jacket → 30 ubar. |
| 1350 | Recovery = 139 cuft/hour, 386709.3 cuft |
| 1355 | MB = 24.4%. Boiling off around 4X faster than normal. |
| 1400 | Recovery = 173 cuft/hour, 386737.7 cuft |
| 1410 | Recovery = 159 cuft/hour, 386765.1 cuft |
| 1415 | Fill LN2 cold trap bath |
| 1420 | Cryostat vacuum jacket = 12 ubar. |
| 1422 | Let 1.9 mbar He gas into vacuum manifold. Then open cryostat vacuum jacket valve to let this into the vacuum jacket. Vacuum Jacket → 46 ubar. |
| 1430 | Recovery = 241 cuft/hour, 386823.3 cuft |
| 1440 | Recovery = 256 cuft/hour, 386866.1 cuft |
| 1450 | MB = 9.4%. That's pretty fast. |
| 1450 | Recovery = 245 cuft/hour, 386907.8 cuft |
| 1450 | Cryostat vacuum jacket = 19 ubar. |
| 1455 | Close valve at cryostat vacuum port |
| 1500 | MC(Cernox)/Sorb/1K Pot = 4.82/6.7/5.35 K. MC/Still heaters = 20/30 mW. Temperatures have risen a little in the last half hour. |
| 1500 | Recovery = 240 cuft/hour, 386948.1 cuft |
| 1500 | Matt leaves lab |
| 1530 | Recovery = 219 cuft/hour, 387061.1 cuft |
| 1530 | MC(Cernox)/Sorb/1K Pot = 4.9/7.1/5.7 K. After this they start rising much more quickly. |
| 1550 | MB = -1.0% (minimum) |
| 1600 | Recovery = 200 cuft/hour, 387166.8 cuft |
| 1600 | MC(Cernox)/Sorb/1K Pot = 5.45/8.8/6.92 K. All rising. |
| 1630 | Recovery = 149 cuft/hour, 387251.2 cuft |
| 1700 | Recovery = 97 cuft/hour, 387308.5 cuft |
| 1700 | MC(Cernox)/Sorb = 10.9/20.8 K. Both rising. |
| 1720 | Recovery = 79 cuft/hour. |
| 1730 | Recovery = 40 cuft/hour. Precipitous drop in boiloff rate. |
| 1800 | Recovery = 12 cuft/hour, 387352.0 cuft |
| 1900 | Recovery = 4.3 cuft/hour, 387357.94 cuft |
| 2000 | Recovery = 2.0 cuft/hour, 387360.48 cuft |
| 2000 | MC(Cernox)/Sorb = 45.8/80.0 K. Both rising. |
| 2100 | Tried to turn off heaters but I think I forgot to set the IGH to remote. |
| 2100 | Recovery = 1.2 cuft/hour, 387361.98 cuft |
| 2100 | MC(Cernox)/Sorb = 56.8/109.3 K. |
| 2200 | Recovery = 0.58 cuft/hour, 387363.75 cuft |
| 2200 | MC(Cernox)/Sorb = 62.2/124.4 K. |