Steve came by the lab today, and looked at the status of the upgraded vacuum system. He recommended pumping on the RGA volume, since it has not been pumped on for ~3 months on account of the vacuum upgrade. The procedure (so we may script this operation in the future) was:
- Start with the pumpspool completely isolated from the main IFO volume.
- Open V5, pump down the section between V5 and VM3. Keep an eye on PTP3.
- Open VM3, keep an eye on P4. It was reporting ~10 mtorr, went to "LO".
- Close VM3 and V5, transition pumping of the RGA volume to TP1 which is backed by TP2 (we had to open V4 as all valves were closed due to an N2 pressure drop event).
- Open VM2.
- Watch CC4.
CC4 pressure has been steadily falling. Steve recommends leaving things in this state over the weekend. He recommends also turning the RGA unit on so that the temperature rises and there is a bakeout of the RGA. The temperature may be read off manually using a probe attached to it. |