janos.csizmazia@LIGO.ORG - posted 20:13, Tuesday 20 February 2024 - last comment - 16:18, Wednesday 21 February 2024(75903)
2-20 vent vacuum diary
Today's activities: - HAM7 pumpdown status: ~1.1E-6 Torr - HAM7 Annulus system pumping cart has been switched off, it is pumped now only by its Ion-pump - Corner pumpdown: the OMC and Y-manifold Turbos have been switched on, roughing pump has been switched off; HAM6 turbo is coming tomorrow. The pressure is already ~4E-6 Torr - All the metal valves have been closed in the corner LVEA - EX pumpdown status: 3.2E-8 Torr: the post-vent RGA scan is ready, the results will be in the comment comment section, once they are published. The comparison with past RGAs is also coming next week. If the results will be considered satisfactory, the Ion-pump will be valved in. The GV will remain closed during FAC works - HAM8 works: the chamber was vented with purge air; the Annulus system was vented with Nitrogen; The Y+ door has been taken off; the Y- 12" blanks have been taken off
EX RGA scans added to the DCC at T2400018
The RGA tree was rebuilt and baked at 150C for 7 days, from the collected scans it looks like the RGA could use more baking at a higher temp. This a known issue with the new PrismaPro RGA that it takes a very high temp (250C or higher) to fully clean it up, but we are limited by the KF connections to the turbo pump on the RGA tree.
Baking will resume this week, and scans collected again next week.