Reports until 14:09, Thursday 31 October 2013
H1 ISC (ISC)
sheila.dwyer@LIGO.ORG - posted 14:09, Thursday 31 October 2013 - last comment - 14:09, Thursday 31 October 2013(8338)
Tip tilts for HAM6

Yesterday Keita had Alexa and I mount some optics in tip tilts to prepare for HAM6 work. 

For OM1 we mounted an optic E1201104 SN3 in tip tilt serial number 2

For OM2 we mounted E1100056-1 serial number 12 in tip tilt serial number 4.  

Both of these were pitched downward after installing the optic.  We tried to balance them by turning the bolt that is on the bottom of the mirror holder, but found that for each of them we had to turn the bolt until it was hitting the tip tilt mount.  This is similar to the situation Kiwamu described in https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=7897

We replaced the silvered, 1and 1/2" 8-83 bolts with 1 inch stainless bolts, which is what is called for in D1001396.  I then thought we should try the same thing for the tip tilt assmebly that had been rejected durring the HAM1 work (serial number 9).  With the optic installed and the 1 inch bolt, the mirror was pitched up, we would have needed to add a longer screw to correct it.  I didn't realize that Joe had reclamped the wire in a effort to solve the large pitch seen in HAM1.  

As I tried to remove the optic I chipped it, Alexa has taken photos, one is attached. 

The small pice that is used to put some tension on the mirror (D1001648, the tip tilt nudge) sticks out somewhat into the mirror holder even when the bolt is loose, meaning that we put a lot of pressure on the optics to get them in.  This creates small scraches along the barrel of the optic where the other two contact points are as we push the optic in, and this is where the optic chipped.  This optic had no serial number and an unpolished barrel.  

We have another optic and will clean it this afternoon. 

Images attached to this report
Comments related to this report
alexan.staley@LIGO.ORG - 14:07, Thursday 31 October 2013 (8340)

Here is the link for pictures of the chipped optic (this is a class A clean optic BS99% 1064nm, ref E1000457-v1)