Sheila, Camilla, Ryan S, Cory (Fellow), Rahul

Given below is the summary of beam alignment work we performed in HAM7 today.

After locking the SQZ beam and the OPO we first checked the alignment on the OPO - it looked good and there was no clipping anywhere. Then we checked the beam on ZM4 and ZM5. Camilla measured the incoming beam on ZM4 to be 5.5inches approximately and it looked well centered on the iris in front of it.

On ZM5 the beam was very high on the optic (we had to remove the face baffle to be able to see the beam on the PSAMS mirror). At first we tried using  ZM4 sliders to center the beam on ZM5, but ran out of range. Hence, we mechanically adjusted ZM4 in pitch (using the pitch adjuster) to bring the beam down on ZM5 and center it (Camilla took pictures for reference). 

The beam from ZM5 to the beam divertor was off in both pitch (beam too low) and yaw (too wide as well, almost missing). We first adjusted ZM5 in yaw (mechanically) to center it on the beam divertor - we also had to push it slightly (less than 3mm) side ways for this purpose. With Yaw looking good on the beam divertor, we tried using sliders for Pitch but quickly ran out of range. I then used the mechanical pitch adjuster, but even that was not enough (ran out of range here too). Hence, I added 50grams of weight to the rear side of ZM5 intermediate mass to pitch it up (by 0.5inch) on the beam divertor. This worked and the beam looked good both in pitch and yaw on the beam divertor. 

Finally Ryan S checked the beam on the periscope and the two irises on SQZT7 table. It was off in Yaw - so I applied a negative yaw (clockwise rotation) on ZM5 mechanically (again the sliders were not enough for this big move) using dog clamps and round end screws (for better yaw control). While I rotated ZM5 in Yaw, Ryan S held an IR card on the periscope (SQZT7 table) and Camilla kept an eye on the beam, telling us when to stop. Once we were satisfied in both pitch/yaw on the periscope, Ryan S looked at the two iris in SQZT7, and he was happy with it as well.

I dogged down ZM5 and also re-attached the face baffle before closing the curtains on HAM7 chamber. Camilla started using sliders to fine tune the alignment.

Tomorrow morning I will take health checks on both ZM4 and ZM5 suspensions.