UMN CDMS Wiki archive
start › cdms › k100 › run_diary › 20160425

2016/04/25 (Monday)

Previous Day

0933 Mixing chamber temperature at 7.5 K, LHe level = 60.7%.
0938 IVC at 6.3E-7 mbar. Isolate IVC. P2=5.5 mbar. Turn on scroll pump to pump out cold trap 1 and P2. Once pumped out, isolate cold trap 1 and put into LN2 bath. Fill bath.
0955 1K Pot started. Currently G1=5.9 mbar, G2= 575 mbar, P1=.8 mbar, P2=2.0 mbar, 1K Pot temperature at 1.47 K and fridge temperature at 7.4 K. Start He 3 pump.
1000 Currently using scroll pump as 1K Pot pump, but quickly switch it over to using the He4 pump as intended. He4 pump seems capable of operating as 1K pot pump.
1005 Isolate and unpower Turbopump. 1K Pot: 1.53K. Open Gate and Condenser Line speedivalve. Open V9, G2: 803.7mbar.
1010 Open V1, V3, and Cold Trap 1 speedivalve. Open V13A to let mixture seep through V12A and slowly condense in fridge. G1 begins slowly rising at a reasonable pace.
1013 While slowly condensing the mixture, the 1K Pot is still down around 1.56K. Open the needle valve slightly to raise the temperature of the 1K Pot to ~1.79K. P2: 45.0mbar. MC Temp: 7.41K and dropping.
1030 MC Temp: 2.1K, 1KPot: 1.84K, P2: 340mbar. G1: 82mbar, G2: 416mbar, P1: 1000mbar. V12A is open at 4%, and we're opening it more every ~10s.
1120 MC Temp: 1.99K, 1KPot: 1.84K, P2: 260mbar. G1: 62.5mbar, G2: 67.4mbar, P1: 1000mbar. V12A is all the way open (has been since 1100). Just letting G1 and G2 stabilize before opening V6.
1144 With G1=62 mbar, G2=67 mbar, P2=320 mbar and oscillating (all other values unchanged), close V3 and V9 and open V6 (12% to start, increased to 12.9%) and commence circulation. MC temperature at 1.97 K and slowly dropping. Close 1K Pot slightly to bring 1K Pot temperature to 1.75 K (P2=32 mbar).
1245 Open V6 to 13.8%, and P1 finally drops from 1000mbar. Temperature begins plummeting. MC Temp: 1.43K and dropping. G1: 115mbar, G2: 156mbar, P1: 100mbar. 1KPot: 1.70K, P2: 18mbar.
1256 Open V6 all the way, G1:117 mbar, G2: 151 mbar, P1:.26 mbar and dropping, P2: 16 mbar, 1K Pot temp: 1.70 K, mixing chamber temperature at 860 mK and dropping.
1316 Open V14, P1 rises to roughly 200 mbar and begins dropping, G2 rises to 160 mbar and begins to drop. Mixing chamber temperature at 155 mK.
1355 Mixing chamber temperature 46.79 mK, G1=72 mbar, G2=90.4 mbar, P1=0.38 mbar, 1K Pot temperature is 1.706 K, P2=18.0 mbar.
1420 With P1=.22 mbar, close V14. Currently G1= 92.1 mbar, G2=104.3 mbar, P1= 75 ubar, P2=18 mbar (1K Pot temperature 1.705) and mixing chamber temperature at 44 mK.
1435 Adjust 1K Pot such that its temperature drops to 1.536 K. This initially causes a rise in mixing chamber temperature, but around 48 mK MC temp begins falling again.
1556 Fill LN2 cold traps full.
1610 MC Temp: ~43mK, Tower Temp: ~47mK.
1710 Mixing chamber temperature at 44 mK (slowly rising but hopefully it will start to drop), 1K Pot temperature at 1.68 K, P2=13.0 mbar, G1=188 mbar, G2=188 mbar, P1= .10 mbar.

Next Day