UMN CDMS Wiki archive
start › cdms › k100 › run_diary › 20140902

2014/09/02

1140 Current Mixing Chamber temperature of 279K and G2 pressure of 502mbar. Commence pumping out IVC with turbopump.
1145 Fill LN2 cold trap full.
1720 Background helium leak rate 2.6E-9 mbar l/s. Commence spray test around 4 indium seals.
1755 Leak rate increased to 3.7E-9 mbar l/s very gradually. Doesn't look like the indium flanges are leaking. Move onto KF- and ISO-flanges above cryostat as these may have moved around a little and a hole may have opened up.
1830 Leak rate started to increase less gradually (but still gradually) when checking flange next to double-flange on top of wizard staff. Leak rate 1E-8 mbar l/s. Wait for leak rate to decrease.
1950 Leak rate has only just started to decrease having reached 1.1E-7 mbar l/s before falling again.
2030 Leak rate has been falling gradually, and has reached 5.5E-8 mbar l/s. Isolate leak checker and evacuate IVC with turbo pump. Let's try again tomorrow, starting at the flange next to the top of the wizard staff.
2100 Fill N2 cold trap full.