Attached are two RGA scans:
- Scan at 10:30am before the cryopump was valved in; 2000 l/s turbo pump only
- Scan at 3pm, about 2.5 hrs after CP was valved in, with 2000 l/s turbo also pumping on main volume
Later in the week we will collect more scans to see how the water is falling.
Total pressure at EX before valving in CP was 5e-7 Torr and is now 5e-8 Torr, as expected, as a result of a full order of magnitude decrease in water partial pressure.
Note that the short CPs allow 30% of water molecules to escape past the trap and into BT; long CPs in corner allow only 3% transmission.
EX is currently isolated from BT with a soft closure of GV19. We typically don't operate in this state (BT valve soft closed with a VEA turbo valved in) in case the turbo pump fails and back streams into main volume, possibly seeping past GV o-ring.
Tuesday 2pm RGA scan 26 hours after valving CP into EX volume.
RGA scan after 67 hours with CP8 valved in (plus 2000 l/s turbo).
EX RGA scan after 99 hours with CP8 valved in. This scan was taken one day after we temporarily (8-hr day shift) opened to x-arm.
Correction on short CP H2O transmission. Value is 17.2% (not 30%), per C960963. Long pumps (in corner station) are 2.6% each.