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2017/01/21 (Saturday)

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Status: Warming up after second blockage discovered. Bath empty, He gas in main bath vacuum jacket and in IVC. Small leak at top of stripline tube. Mixture is in dump, fridge evacuated.
1235 MC(Cernox) = 282 K, IVC = 14 mbar.
that's quite high for the IVC. Maybe air leaked in. Will want to pump this out and put in fresh He.
1240 Put LN2 traps in bath and fill bath
1250 Perform near-room-temperature throughput test (through cold Trap 1)
  1. All mixture in dump, LN2 traps cold, condenser & still valves open (3He pump on - optional)
  2. Open V9, V13a, V12a+speedivalve, V3. Wait for G1 to be close to G2.
  3. Close V12a+speedivalve and V3, open V1
  4. monitor G1
Room temperature throughput test result: let G1 rise to 630 mbar before Step 3, then it falls to 50 mbar and begins to rise. Throughput: 8.5 mbar/min
1305 Pump mixture back to dump
1305 Pump out IVC with turbo pump for a few minutes to around 10 μbar. Then fill with 4.6 mbar He exchange gas
1320 Begin pumping out main bath vacuum jacket with scroll pump. After 10 minutes switch to turbo pump.
1325 Begin cryocleaning mixture through LN2 Cold Trap 2
1430 Turbopump = 0.1 μbar, main bath vacuum jacket = 10 μbar. Stop pumping out main bath vacuum jacket.
1500 Stop cryocleaning, pump mix to dump. Cleaned for 95 minutes.
1515 Remove Trap 2 from bath to let it warm up

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