aLIGO LHO Logbook

H1 SUS (ISC, SEI, TCS)

jeffrey.kissel@LIGO.ORG - posted 16:59, Thursday 30 November 2017 - last comment - 09:19, Friday 20 June 2025(39590)

B&K Hammer Done in HAM3 Baffles, SR2 Cage, and of Primary/Final/Large in-vac TCS Steering Mirrors in BSC2

J. Kissel, S. Pai

Siddhesh and I B&K Hammer'ed the new MC2 and PR2 Scrapper Baffles, SR2 Cage, and of Primary/Final/Large? in-vac TCS Steering Mirrors in BSC2. More details, pictures, and results to follow.

Notes for myself later: 
- SR2 cage accelerometer was oriented with X Y Z aligned with the IFO global coordinates. 
- All other measurements had acc Y aligned with IFO Y, and acc Z aligned with IFO X.

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jeffrey.kissel@LIGO.ORG - 09:19, Friday 20 June 2025 (85195)

Link

Adding an oldy-but-goldy picture of MC2 (background) and PR2 (foreground) taken by Conor Mow-Lowry the day of this BnK exercise. The picture is taken from the -Y HAM 3 door, so IFO +X and the beam splitter is to the right, and +L for both suspensions is to the left as their HR surfaces point back toward HAM2 (to the left).

Critical to today's yak shaving: the OSEM measuring Transverse at the top mass (M1) stage is toward the camera for both suspensions, i.e. in their +T direction, which means it's the "SIDE," or SD OSEM, per E1100109 (rather than the OPPOSITE SIDE, or OS).

(yak-shaving: while putting together the derivation of the OSEM2EUL matrices in G2402388), I'm reminded that some HSTS were assembled with the Transverse sensor on in the OS position, and I'm on the hunt as to which ones -- and making sure the (SD to T) & (T to SD) element OSEM2EUL & EUL2OSEM matrices, respectively, are correctly -1.0 if SD and +1.0 if OS.)

MC2 and PR2's OSEM2EUL matrix value H1:SUS-[MC2,PR2]_M1_OSEM2EUL_2_6 is correctly -1.0.

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