gerardo.moreno@LIGO.ORG - posted 10:43, Monday 02 June 2025 - last comment - 14:45, Tuesday 03 June 2025(84715)
HAM1 Vent Recovery Update
HAM1 annulus system appears to have issues pumping down, currently its annulus ion pump is railed 10 mA, and the pump cart pumping on this system is sitting at 6.04x10-05 Torr, see attached photo.
Process thus far:
- Last Thursday I managed to go and visit some of the -Y door bolts, found out that most of the bolts from 3 to 7 O'clock were not tigth, I was able to get 90 degrees turn, one bolt was actually loose, I was able to turn it by hand, but those were the only one that I was able to work on, since I was asked to stop work at HAM1.
- Another test done was to check for leaks on the aux cart pumping line, so the cart was isolated via the annulus system isolation valve, the pressure dropped at the aux cart down to 4x10-06 Torr, meaning that no leak is on the pumping side, the isolation valve was opened again to continue pumping.
I plan to visit HAM1 to check the rest of the bolts on -Y door and +Y door.
Images attached to this report
Comments related to this report
HAM1 internal pressure is doing good, see attached photo of the pressure at the SS-500 pump cart pumping on HAM1. Second attachment is a 5.5 day plot of the pressure internal to HAM1, the large step noted on the plot is due to the introduction of HAM1 ion pump.
Images attached to this comment
(Jordan V., Gerardo M.)
Today we went and performed the following on the annulus system for HAM1:
- Disconnected the communications cable, to make sure that the controller is doing its part, used a DB9 connector with the required jumpers, controller behavior did not change. Removed the bridged connector and reconnected the communication cable. No change noted.
- Isolated the ion pump via its isolation valve, pressure started to drop, but as soon as the isolation valve was open the pressure goes up. Valve returned to open, pressure went up.
- Then we moved to torque some of the bolts on both doors, only the ones that are reachable without bumping on sensitive parts. Thus far no change on pressure of the annulus.
Now we wait to see the results of today's changes overnight.