C. Compton, S. Dwyer, J. Oberling

This morning we removed the KTP wedge assembly (D2000038) from the OFI and moved it into the OSB Optics Lab.

We began by trying the "transport shims" that are supposed to help secure the OFI.  Unfortunately, these did not work.  The slot in the shims was not wide enough to fit around the OFI Earthquake Stop Posts we were supposed to fit them around, and the shims were too skinny (the posts bottomed out before contacting the shims).  So we had to pivot to Plan B, which was to use dog clamps instead.  This mostly worked, but the OFI still moved around enough that we decided one of us would try to support the OFI while the other turned bolts.  Camilla has some pictures of this and will post as a comment to this alog.  Even still, we managed to almost immediately dislodge one of the OSEM magnets (the one near the lone +X/+Y OSEM) as soon as we started trying to remove the KTP wedge assembly (the magnet is still stuck to the flag on the OFI, will need to have its polarity checked and be put back in place).

We first placed a teflon sheet in between the KTP wedge and the quartz rotator assembly.  Using non-magnetic tools (a titanium hex key that had been bent so it would fit in the space between the KTP and FS wedges, and a beryllium copper one that had been cut short) we attempted to remove the beam dump assembly from the KTP wedge assembly.  Camilla held the OFI and I tried to loosen the bolts holding the beam dump on the KTP wedge.  I say "tried" because the bolts are frozen in place.  We were unable to get them to move, at all.  Pivoting again, we found that the beryllium copper hex key was short enough to fit under the beam dump assembly, so we began loosening the two bolts on the +Y side of the KTP wedge assembly; Camilla had to crawl in the -X door to access the -X bolt while I held the OFI.  This worked until the -X bolt was loose enough that we could no longer fit the hex key under the beam dump assembly.  At this point Sheila used a T-shaped titanium hex key to loosen the -Y bolt on the KTP wedge (the bolt directly under the quartz rotator) while I held the OFI, and then I loosened the +X bolt.  With these 2 bolts loose we were able to lift the KTP wedge assembly enough that Camilla could fit the hex key under the beam dump assembly again.  In this way were able to slowly work the -X bolt free.  With all bolts free I carefully removed the KTP wedge assembly while Sheila held the OFI.  We Ooohh'd and Ahhhh'd at the craters in the KTP wedge for a bit and took some photos (see attached), and Camilla and Sheila grabbed some more pictures of the back side of the FS wedge (more access, and therefore better viewing, with the KTP assembly out of the way).  We also removed the teflon sheet from in front of the quartz rotator.

We ensured all of the non-magnetic tools were separate from other tools in the cleanroom, safely wrapped up the tools we would need as well as the KTP wedge assembly, and moved everything to the optics lab to start prepping for swapping and realigning the KTP wedge assembly (the beam dump assembly will have to be removed in the Optics Lab).  I've attached a few closeup pictures of the KTP; 2 are viewing the front surface and one is viewing the back surface (better view of the coating damage around the craters).  Camilla has several other pictures that she'll attach as a comment to this alog.