Continued from 90691. Betsy, Keita, Sheila, Oli, Eric, Camilla, Ryan S, Jenne

First thing, we went back to alignment we had ITMX SQZ  the "flashes" and "fly-bys" yesterday, put the same size oscillation on the BS, but saw no flashes of fly bys. Betsy took a video of what the two SQZ beams looked like at PR2 at this alignment, they were crossing each other. 

We then rethought the alignments from yesterday, we are leaving:

• ITMX and ITMY at March DRMI top mass OSEM sensors
• ZM4 and ZM5 to get SQZ beam on SQZT7 irises
• ZM6 to O4 sliders.
• SR3 at the Oplev/slider positions of March DRMI/O4 (all similar)
• SR2 Yaw slider back to O4, Pitch to get SQZ ITMY beam on AS_AIR (+440urad PIT sliders different from O4).
• SRM aligned to improve SRY fringes (+200urad PIT sliders, +400urad YAW sliders different from O4).

Once we did this, we had SRY fringes, Betsy and I then adjusted the BS to bring the beams back on top of each other at PR2. This was a change in the BS sliders from (P 1000, Y 1290) to (P 1350, Y 1180).

Keita then wobbled ITMX and found the SQZ beam off ITMX! Aligned ITMX to get MICH flashes at AS_AIR, AS_A/B and ISCT1 REFL. He had to move ITMX from (P -96, Y 104) to (P -280, Y 94). 

He then got the PSL IX and IY reflection in the AS_AIR camera in this alignment. Sliders at this alignment attached. 

However as we are not sure we trust the ITMY alignment form top mass osems (from 90551), we want this Pitch change to be in ITMY, so ITMX is at it's known DRMI pointing. We could try to walk these, maybe along with SRC which might reduce some of our Pitch differences in SR2 and SRM. This change is so small that we will go ahead with mechanically offloading BS Pitch. The BS YAW will not mechanically changed. 

The OMs are also not currently in their O4 sliders/osems position, attached. We could verify the SQZ beam pointing by putting these back if we thought that was needed.