Koji pointed out during the group meeting that I should compensate for local tilt when I move the beam around the mirror for calculating the loss map.
So I did.
Also, I made a mistake earlier by calculating the loss map for a much bigger (X7) area than what I thought.
Both these mistakes made it seem like the loss is very inhomogeneous across the mirror.
Attachment 1 and 2 show the corrected loss maps for ITMX and ETMX respectively.
The loss now seems much more reasonable and homogeneous and the average total arm loss sums up to ~ 22ppm which is consistent with the after-cleaning arm loss measurements. |