BHR Upgrade Phase I - Vent of Fall 2021

Venting process

Mon Oct 18th, 2021

• Checked the main volume is isolated.
• TP1 and TP2 were made isolated from other volumes. Stopped TP1. Closed V4 to isolate TP1 from TP2.
• TP3 was made isolated. TP3 was stopped.
• We wanted to vent annuli, but it was not allowed as VA6 was open. We closed VA6 and vented the annuli with VAVEE.
• We wanted to vent the volume between VA6, V5, VM3, V7 together with TP1. So V7 was opened. This did not change the TP1 pressure (P2 = 1.7mmTorr) .
• We wanted to connect the TP1 volume with the main volume. But this was not allowed as TP1 was not rotating. We will vent TP1 through TP2 once the vent of the main volume is done.
• Started venting the main volume@Oct 18, 2021 9:45AM PDT
• We started from 10mTorr/min, and increased the vent speed to 200mTorr/min, 700mTorr/min, and now it is 1Torr/min @ 20Torr
• 280Torr @11:50AM
• 1atm @~2PM

We wanted to vent TP1. We rerun the TP2 and tried to slowly introduce the air via TP2. But the interlock prevents the action.

Part I: Optics removal on westside of BS Table

Part II: Relocation of TT2 and MMT1/2 alignment to TT2

Part III: PRC Folding mirror placement

Part IV: SR3 replacement

Part V: LO Path up to LO2 setup

Part : AS Path setup

Part : BS Path setup

Part : POP Path setup

Part : POX Path setup

Part : POY Path setup

Part : AS RFPD Path setup

Part : Green transmission paths

Part : ITMX oplevs

Can we push the mirrors back to keep more clearance?

Part : ITMY oplevs

Part : BS, PRM SRM oplevs

Part : Place PRM and SRM

Part : Pre-pump alignment and clearance check

Pump down

Elog posts

* 40m/16410: Vent Started/Completed