| Status: | Fridge warming after blockage found |
| 0820 | MC = 215 K, IVC = 2.2e-1 mbar |
| 0825 | Fill LN2 cold trap bath. Trap 1 in bath, Trap 2 at room temperature |
| 0830 | Pump GHS contents to dump, then open Still and Condenser to GHS. No increase seen in pressure. Pump fridge to dump. |
| 0840 | Stop pumping fridge to dump. P1 = 0.4 mbar, G1 = 0.0.85 mbar. |
| 0850 | Begin cryocleaning mixture through Trap 1. V6 open to 12.8%. G2 increases from 626 to 640 mbar then settles to 628 mbar. |
| 0855 | Open V6 further, to 13.0%. G2 increases to 750 mbar then relaxes slowly (down to 650 mbar after 15 minutes). G1 falls a little, from 682 to 679 mbar. Trap outlet port gets a little frosty. |
| 0930 | Trap outlet no longer frosty and closing V13a does not cause change in G2. So open V6 more, to 13.2%. G2 climbs to 883 mbar then begins to fall again. |
| 1105 | Mixture still flowing (i.e. closing V13A causes G2 to rise). Cease cryocleaning mixture. Pump mixture to dump in preparation for a throughput test. |
| 1125 | G1: 0.6mbar, P1: 0.006mbar, G2: 794mbar. Isolate Cold Trap 1, and begin closing V6. |
| 1130 | G2: 795mbar. Get ready for throughput test. |
| 1145 | Open Gate and Condenser Line speedivalve. P1 rises from 6ubar to 40ubar. Maybe remnants of blockage? Perform throughput test. |
| 1150 | Throughput rate: 14mbar/min. Looking good. Pump all mixture to dump. |
| 1200 | 794mbar mixture collected in dump. P1 back down to 6ubar. Close fridge lines, and all IGH valves. Isolate mix in dump. Turn off He3 circulation pump. |
| 1210 | Add more He exchange gas to IVC to bring total to 5.6mbar. |
| 1215 | Shut off He recovery valve from Main Bath and commence LN2 transfer. |
| 1240 | MC = 222 K and falling, IVC = 4.6 mbar |
| 1300 | MC = 205 K, IVC = 3.4 mbar |
| 1310 | Remove Trap 1 from bath to warm up. Open trap to G1 to measure how much contamination was removed. |
| 1330 | MC = 158 K, IVC = 2.5 mbar. Sorb thermometer still pegged at max (250K) |
| 1345 | MC = 141 K, Sorb = 236 K |
| 1400 | Trap 1 pressure 20.5 mbar and flat |
| 1420 | Pump out Cold Trap 1 through V2, V7, V2A, V5A. |
| | Resistance measurement of the Main Bath reads 1.28kΩ indicating that the bath has a decent amount of LN2 in it, and could be ended soon since we'll be blowing out early tomorrow anyway. |
| 1430 | MC = 107K. Resistance of Main Bath reads 1.31kΩ, which is good enough. Cease LN2 transfer and attach ping pong ball on He Recovery port on top of Main Bath. |
| 1455 | MC = 99 K, Sorb = 132 K, IVC = 1.9 mbar |
| 1505 | P2 has been pumped down to 20ubar. Isolate LN2 cold trap 1 and close all valves on IGH. Isolate scroll pump with manual valve and unpower. Leave LN2 cold traps warm overnight, so we can cool them down tomorrow as we blow out the LN2 then commence a clean. |
| 1530 | Perform 77K electrical checkouts. All looks ok except DIB1qI to QET return reads low conductance, might be open. (Also kOhm shorts from DIB1pD and DIB2pD feedback coils to chassis, not relevant to this run. Were those there before? May not have checked.) |
| 1535 | MC = 89 K, Sorb = 127 K, IVC = 1.9 mbar |