BHR Upgrade Phase I - Vent of Fall 2021

1. 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.

2. Part I: Optics removal on westside of BS Table

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

4. Part III: PRC Folding mirror placement

5. Part IV: SR3 replacement

• Clear East side of BS table

6. Part V: SRM Oplev setup

7. Part V: POY Path setup

8. Part VI: LO Path up to LO2 setup

9. Part VII: AS Path setup

• Clear the ITMY table. Following optics need to be removed:
  • POYM1
  • ITMY OL1
  • ITMY OL2
  • ..

10. Part VIII: BHDBS Path setup

• Setting up LO3, LO4, BHDBS

11. Part IX: POP Path setup

12. Part X: POX Path setup

13. Part XI: AS RFPD Path setup

14. Part XII: Green transmission paths

15. Part XIII: ITMX oplevs

Can we push the mirrors back to keep more clearance?

16. Part XIV: ITMY oplevs

17. Part XV: Place PRM and SRM

18. Part XVI: BS, PRM oplevs

19. Part XVII: Pre-pump alignment and clearance check

20. Pump down

21. Elog posts

* 40m/16410: Vent Started/Completed