TravisS and RickS

Yesterday, we switched on the Pcal laser at Yend to check the alignment of the beams after the replacement of the ETM.

With the ETM in the nominal alignment according to the optical lever, we found that the Pcal beams at the Rx side are badly misaligned, one beam actually missing the relay mirror.

This is likely due to either a) the ETM not being properly oriented or b) the Pcal periscope orientation having shifted during B&K measurements or the addition of vibration dampers back in January.

We plan to investigate early next week, going inside the vacuum envelope and installing the Pcal target on the ETM suspension structure.