jason.oberling@LIGO.ORG - posted 12:43, Wednesday 08 February 2012 (2184)
ETMy Test Stand Alignment Progress
J. Oberling
After yesterday's round of adjustments and letting everything settle overnight I measured the position of the ETMy and the position/pointing of both the ETMy and ERM. As usual all yaw directions are reported assuming a top down view of the ETM/ERM and all position directions are reported using the local End Y cardinal directions.
-
ETMy Longitudinal error: 4.0mm West
- Spec currently listed as ±3mm, but there has been discussion on relaxing this
-
ETMy Horizontal error: 0.97mm North
- ±1mm spec
-
ETMy Vertical error: 0.13mm low
- ±1mm spec
-
ETMy Pitch: ~605 µrad down
- 639 µrad down desired pitch with a ±100 µrad spec
-
ETMy Yaw: ~120 µrad CW
- 0 µrad desired yaw with a ±100 µrad spec
-
ERM Pitch: ~2.3 mrad down
- 1.86 mrad down desired pitch (to coincide with AR surface of ETM) with a ±1.47 mrad spec
-
ERM Yaw: ~70 µrad CW
- 0 µrad desired yaw with a ±1.47 mrad spec
I also measured the ETMy/ERM gap using the Keyence system at the two positions we initially measured yesterday.
- Position 1 - 12 o'clock on the ETMy, ~3" from the edge: 5.25mm
- Position 2 - 10 o'clock on the ETMy, ~1" from the edge: 5.22mm
The desired gap is 5mm. The tolerance as listed in the IAS BSC06 alignment procedure (E1101071-v3, page 17) is ±0.5mm average center distance and ±1.47 mrad pitch and yaw (parallelism). With that as the spec the gap is properly set and the ERM is properly aligned.