J. Kissel, T. Sadecki
Today, we adjusted the pointing of the ITMx TM to get the OpLev beam out of the receiver viewport that houses the OpLev PD. We then aligned the reaction chain such that the CP HR reflection overlaps with the TM AR reflection, thus ensuring parallelism of the inner surfaces at the TM level. We did not check the 20mm spacing between the chains as time was running short for the day, so we'll have to re-assess that at a later time. This was mostly a check that we had range in the pitch and yaw adjustment to get us where we need to be. We did, but just barely, as we used up most of the four main chain fine pitch adjuster ranges to get us there. We then reinstalled and centered the top mass BOSEMs for both chains and the PUM AOSEMs. We did not bother with the most fussy, UIM level BOSEMs as Jeff noted that for the bounce/roll mode measurements we need to tune BRDs, the PUM OSEMs will suffice. Next up: run TF measurements to check for overall health/rubbing, take bounce/roll measurements for BRD tuning, and set up for the final round of fully suspended violin mode measurements.
There was a slight misunderstanding regarding which beams we were supposed to make overlap that I only noticed when perusing Jeff's photos. Jeff was directing me to align the CP Surface 1 (HR) reflection to the ITM HR reflection. According to E1200951, section 7.1.10, the CP should be aligned to the ITM AR surface, therefore the CP HR and ITM AR reflections should overlap. We'll revisit this alignment next week since only the reaction chain will need realignment, which would have happened regardless due to further tuning of UIM OSEMs, etc.