| | Status: First LHe transfer was yesterday. MC (Cernox) cooling overnight, turbo pump pumping out IVC. Cf source in shield for activation purposes. |
| | Both traps are at room temperature being pumped out by 4He pump. P2 = 0.018 mbar. |
| 0930 | Sorb/MC(Cernox)/Tower = 16.6/18.2/18.5 K. IVC pumping/valved out = 3.0e-7/1.6e-6 mbar. Main bath = 46.4%. |
| 0940 | Isolate IVC. |
| 0945 | Close GHS valves and 4He pump valve, turn off 4He pump |
| 0950 | Place cold traps in LN2 cold trap Dewar and fill LN2 cold trap Dewar. |
| 0955 | Let mix into Trap 1 from dump. Leaving 3He pump off. With V9 open and pump off, G2=758.3 mbar. Open V13a: G2 falls to 712 mbar. |
| 1005 | Let mix into fridge through Condenser valve, V1, and Trap 1 speedivalve. Also open gate valve to still to view pressure on P1. (This of course opens an additional large volume for mixture to expand into: the circulation pumping line.) |
| 1010 | G1/G2 = 610/635 mbar and falling. Sorb = 10.8 K and falling. MC(Cernox) = 17.8 K |
| 1015 | Open 1KPot needle valve 45 degrees. Sorb and 1KPot temperatures start to fall. |
| 1020 | Pot fell to 6.6 K but then rose again. Sorb fell to 8.0 K but also rose again. Sorb = 8.7 K. Still/Coldplate = 16.0/NaN(?) |
| | cold plate resistance looks like a normal value but the vi doesn't translate it to a temperature, don't know why |
| 1025 | Close V13a to isolate some mix in the dump. G2 = 553 mbar. |
| 1030 | Start pumping on 1KPot. G1 dropping < 500 mbar, Sorb ~ 4K, 1KPot → 3.1 K / 6.0 mbar. |
| 1045 | Pot slowly cooling, G1 falling slowly. 1KPot = 2.15 K / 6.0 mbar. Still/MC(Cernox)/Tower = 5.6/17.5/17.8 K. Cold plate thermometer still not reading right. |
| 1050 | Open 1KPot needle valve another 5 degrees to increase cooling power (pumping pressure is still lowish, 6 mbar) |
| 1110 | 1KPot = 1.72 K / 18.0 mbar. G1 = 228 mbar. MC(Cernox) = 16.4 K. |
| 1115 | Letting more mix into fridge in controlled fashion. Open V13A but watch 1KPot pressure, close again if it climbs high. |
| 1120 | Leave V13a open. G2 falling. |
| 1125 | 1K Pot = 2.3 K / 18.0 mbar. G1/G2 = 380/440 mbar, getting closer to one another. Still/ColdPlate/MC(Cernox)/Tower = 3.7/6.1/14.1/14.2 K |
| 1135 | Open V12a completely, allow mix to flow freely into fridge. Small increases in G1 and 1KPot. |
| 1145 | G1/G2 = 405/365 mbar. Still/ColdPlate/MC(Cernox)/Tower = 3.2/4.9/3.24/4.51 K. 1K Pot = 2.2 K / 18.0 mbar. |
| 1200 | G1/G2 = 215/205 mbar. Still/ColdPlate/MC(Cernox)/Tower = 2.4/3.6/2.70/3.92 K. 1K Pot = 2.2 K / 18.0 mbar. |
| 1210 | Close V13a and turn on 3He circulation pump. This pushes mix that's in the pump into the dump. G2 rises from 160 to 168 mbar. Then reopen V13a. |
| 1220 | G1/G2 = 105/100 mbar. Still/ColdPlate/MC(Cernox)/Tower = 2.0/2.9/2.36/3.19 K. 1K Pot = 1.62 K / 7.0 mbar. Open needle valve additional 20 degrees. |
| 1225 | Close V9 leaving 80 mbar in dump. |
| 1230 | 1KPot spikes for no apparent reason. Delayed response? Pressure settling around 75 mbar. Close needle valve about 10 degrees |
| 1235 | G1/G2 = 80/70 mbar. Still/ColdPlate/MC(Cernox)/Tower = 2.1/3.0/2.29/2.32 K. 1K Pot = 1.76 K / 34.0 mbar. |
| 1240 | Start circulation: open V6 to 12%. Then start opening further in steps of 0.5%. |
| 1248 | At V6 = 13.5% response is seen: Circulation and 1KPot pressures increase. Still temperature starts to decrease. |
| 1250 | G1/G2 = 225/250 mbar. Still/MC(Cernox) = 1.9/1.59 K. 1K Pot = 1.76 K / 34.0 mbar. |
| 1255 | At V6 = 14.0%, still pressure(P1) falls into readable range. Falls as low as 10 mbar, some oscillation. |
| 1300 | V6 = 14.0%, G1/G2 = 125/155 mbar. Still = 1.26 K / 20 mbar, ColdPlate/MC(H35)/Tower = 1.30/1.33/1.21 K. 1K Pot = 1.75 K / 30.0 mbar. |
| 1300 | Still pressure oscillations stop. Was spiking between about 5 and 50 mbar. Now staying below 5 mbar. |
| 1315 | V6 = 14.5%, G1/G2 = 125/120 mbar. Still = 1.09 K / 2.8 mbar, MC(H35) = 0.74 K. |
| 1340 | V6 = 16.5%, G1/G2 = 100/95 mbar. Still = 1.26 K / 0.380 mbar, MC(H35) = 0.153 K. |
| 1340 | V6 = 100%, G1/G2 = 100/95 mbar. Still = 1.09 K / 0.140 mbar, MC(H35) = 59 mK. |
| 1350 | Begin opening then closing V14 to let the rest of the mix into circulation. Throttle to keep circulation pressures between 80 and 160 mbar. MC has fallen as low as 30 mK but increases as high as 100 mK when more mix is let in. |
| 1430 | Leave V14 open to get all mix in fridge |
| 1550 | G1/G2 = 100/95 mbar. Still = 1.11 K / 0.240 mbar, V14 open. ColdPlate/MC(H35)/Tower = 151/28.9/40.3 mK. |
| 1555 | Almost all mix is out of dump, so close V14 |
| 1600 | Commence LHe transfer (30.3%). |
| 1645 | G1/G2 = 100/95 mbar. Still = 1.11 K / 0.120 mbar, ColdPlate/MC(H35)/Tower = 150/28.3/39.5 mK. 1K Pot = 1.73 K / 28.0 mbar. |
| 1710 | Cease LHe transfer (92.8%). |
| 1715 | Fill LN2 cold trap full. |