Reports until 18:08, Monday 04 March 2024
LHO VE
janos.csizmazia@LIGO.ORG - posted 18:08, Monday 04 March 2024 - last comment - 09:47, Tuesday 05 March 2024(76105)
3-4 vent vacuum diary
The pressures:
HAM7: ~2.3E-7 Torr
HAM8: ~5.1E-7 Torr
Corner: ~7.9E-8 Torr
EX: ~1.9E-8 Torr

Today's activities:
- EX Turbo pump was valved out. The pressure rises, but will be consolidated at ~2.3E-8
- EX further schedule: it will be valved in to the beamtube at 3-5 - GV20 will be opened

- Another corner RGA scan has been taken at the OMC beam: it shows, that now Hydrogen has the highest partial pressure, water is only at the 2nd place
- The controller of IP1, IP2, and IP3, and IP14 (HAM6) was replaced with old style rebuilt controllers, which has higher maximum current, and therefore handles the pumps much better - they are not railing anymore but pumping nicely; but, they are now invisible in CDS - this needs attention very soon
- Corner further schedule: as the pressure is coming down nicely (and the IPs are happy), if everything stays like this, at 3-5 the main GVs (GV5; GV7) can be opened

- HAM8 RGA bakeout is ramped up, now it is baking for a few days
- HAM7 RGA bakeout was done, and a scan was already taken. It shows that the RGA needs more bakeout, and also that the chamber is free from poisonous gases
- So, the HAM7 IP was valved in, hence the huge pressure drop
- Relay tube - HAM7 - HAM8 further schedule: This volume will be valved in to the main volume around Wednesday-Thursday - RV1; FCV1; FCV2; FCV3; FCV4; FCV8; FCV9 will be opened
Comments related to this report
jordan.vanosky@LIGO.ORG - 09:47, Tuesday 05 March 2024 (76115)

HAM7 RGA scans posted to T2400018

RGA was baked for ~3 days at 175C prior to scans. Comparison to pre-vent scan attached, still RGA volume background limited for AMUs>45, but no appreciable difference compared to pre-vent scan

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