IAS: D. Cook, J. Oberling
SUS: B. Weaver, T. Sadecki
SEI: H. Radkins
After a couple days of adjustments, re-adjustments, and re-re-adjustments, the BS cartridge alignment is complete. Below are the position and angle errors from nominal (error direction in parentheses where required).
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Longitudinal: 0.0 mm
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Lateral: 0.1 mm (right)
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Vertical: 0.28 mm (high)
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Pitch error: 20 µrad up
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Tolerance: ±100 µrad
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Target: 446 µrad up
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Actual pitch: 466 µrad up
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Yaw error: 10 µrad CW
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Tolerance: ±100 µrad
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Target: 0.0 µrad
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Actual yaw: 10 µrad CW
We also aligned the HR and AR BS elliptical baffles. The spec for baffle alignment is ±0.5 mm both laterally and vertically. The AR elliptical baffle was aligned with a lateral error of 0.47 mm to the right (facing the baffle from the AR side) and a vertical error of 0.05 mm up. The HR elliptical baffle was aligned with a lateral error of 0.25 mm to the left (facing the baffle from the HR side) and a vertical error of 0.0 mm. This closes out the BS cartidge alignment.
Betsy, Travis
Further notes on the elliptical baffle:
1) We did not encounter the issue that the alignment pins on the target would not fit in the baffle as seen at LLO in this alog - https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=4425. Our pins fit fine into the baffle.
2) However, we DID run into the problem they mentioned where one of the press-fit pins was too tight of a fit in the target. At LLO they apparently reamed out the hole, again mentioned in their alog cited just above. However, since I read that log too late, we forced the pin into one of the targets and broke it off. (Phlltt!) We weren't given much of a hint to assembling/using these, however we were given a spare! Lesson-learned the hard way and we more-carefully assembled the second AOS baffle target.
3) I don't see how the baffle alignment is captured in the mechanics of the baffle if it gets removed. We've been working under the impression that the baffle cannot come off once aligned, which does make installation a bit trickier. Baffle RODA's assure us the baffle is supposed to be "removeable" so we'll pursue how to maintain the alignment with AOS as we haven't stumbled on that in an LLO log.
4) The method of how we aligned the baffle today seems to be the same as what LLO reported in the cited alog above.
4) Lastly, it seems strange to me that the optic height tolerance is 1mm, while the baffle tolerance is 0.5mm.