UMN CDMS Wiki archive
start › cdms › k100 › run_diary › 20231024

2023/10/24 (Tuesday)

Previous Day

* Lab in-personnel: Himangshu

0855 IVC closed and pressure valve closed. CVJ on turbo overnight. Main Bath is up(fridge closed)
0930 Turbo on IVC = 16 nbar, with turbo valved out for a min = 120 nbar
1002 Check contents of warm LN2 Trap 1: 10 mbar (11 on G1). Pump it out with the scroll pump.
1005 Insert cold trap 1 into the LN2 bath, begin filling with LN2
1011 We are out of LN2. Refilling now
1100 Checked CVJ pressure again. With scroll: 54 ubar, with scroll valved out for a minute: 86 ubar
1158 Fill LN2 in the cold trap 1.
Pump out fridge lines:
  1. Make sure mixture is isolated in the dump.
  2. Check fridge pressures by opening condenser speedivalve+V1 and still gate valve: LHe trap+Condenser(G1)/Still(P1) = (47.5-2.4=) 45.1/0.13 (1.2-0.07)) mbar.
  3. Connect scroll pump to He-4 pump line, turn it on.
  4. Open pump line valve, V5A, V2A, V7, V2, wait a minute, then open V3.
  5. You're now pumping on the fridge lines. Wait until P1 and G1 flatten out.
  6. Close condenser speedivalve and still gate valve, V1, V3, V2, V7, V2A, V5A and close and turn off the scroll pump.
1230 G1 fell to about 1 mbar then rose to now 1.6 mbar, P1 still falling. Stopped at P1=0.45 mbar
1235 Throughput test procedure, Cold Trap 1:
  1. All mixture in dump, LN2 trap 1 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
1245 Perform mixture throughput test at MC = 300 K using above procedure with 3He pump on. Let G1 rise to 600 mbar before Step 3, then it falls to 48.5 mbar on step 4 and starts to rise. Throughput = 6.5 mbar/min.
1317 Pump mixture back to dump:
  1. Close V13A then turn on the 3He pump.
  2. Open V12A+speedivalve, V3.
  3. Open V6 initially to 11%, then further in steps to 30%, making sure G2 doesn't rise too quickly.
  4. Continue pumping until G1 stabilizes at a minimum value (typically a few mbar) and P1 is less than 0.1 mbar.
  5. Stop pumping on cold trap 1, close V12a and speedivalve.
  6. Stop pumping on fridge, close still gate valve, condenser speedivalve, V1, V3.
  7. Close V6, then when V6 is fully closed, close V9.

Next Day