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2015/03/16

1300 With mixing chamber temperature at 18.6 K, Sorb temperature at 19.2 K and a leak rate of 2.9E-9 mbarL/s in line leading up to isolated IVC, conduct leak check on IVC. Leak rate rose to 1.1E-7 mbarL/s and stabilized.
1305 Open turbo pump to line and isolate leak checker.
1330 P1=4.5 mbar, G1=11 mbar. Opened V6 and V9. Fill LN2 cold trap full.
1355 Close V6 (P1=15 ubar, G=1.5 mbar, G2=672 mbar) and close V9. After a few moments P1 has increase 24 ubar. Commence cryocleaning through cold trap 2.
1512 Commence pumping mixture back to dump.
1530 David is isolating the IVC. Begin pumping out mixture capsule in preparation for mass spectrometer analysis.
1636 Commence pumping out on mixture capsule with turbo pump.
1655 Background leak rate of 1.0E-10 mbarL/s on mixture capsule (capsule still isolated). Open IVC to turbo pump and open capsule to leak checker.
1703 After allowing background rate to stabilize, a background leak rate of 3.0E-10 mbarL/s was found. Commence spray leak check on mixture capsule. Leak rate rose to 3.1E-10 mbarL/s during test, in line with background and suggesting no leak. Isolate IVC and leak checker, and resume pumping on mixture capsule with turbo pump.
1730 Isolate mixture capsule and turbo pump. Commence turning off turbo pump. Attach capsule to the vent valve.
1750 Start turbo pumping through He-4 rotary pump lines on lines leading to vent, with vent valve open.
1835 Commence LHe transfer (36.4%).
1905 End LHe transfer (80.7%).
1915 With mixture capsule attached to vent valve, close vent valve and all valves on IGH, including speedivalves.
1923 Turn off turbo pump.
1925 With G1=1 mbar (fluctuating slightly) and P1=150 ubar, open cold trap 1 speedivalve and V12A with some mixture in cold trap 1. G1 rises to 87 mbar. Close cold trap 1 speedivalve and V12A. Then open V3 to open G1 up to P1. G1 falls to 1 mbar and P1=160 ubar. Close V3 and open V2 and V7. G1=1.3 mbar, open vent valve. G1 rises/oscillates for a moment to 1.5 mbar before settling back down to 1.2 mbar. Close vent valve and open capsule valve, allowing mixture to flow into capsule (should be a very small amount of mixture at this point). Close capsule valve to secure tiny portion of mixture in the capsule. Open V5, V9 and vent speedivalve to pump mixture to dump.
1952 Reattach turbo pump to IVC lines and start turbo pump. Close vent valve, V7 and V2 to isolate vent lines from pump. Open V6 and cold trap 1 speedivalve. Remove mixture capsule from vent valve.
2005 Commence pumping on IVC with turbo pump.