keita.kawabe@LIGO.ORG - posted 17:08, Tuesday 03 April 2018 - last comment - 12:57, Wednesday 04 April 2018(41274)
replacing 1" pico mirror with fixed one in OMCR path, removing OMCR components downstream of SiC dump (Sheila, Keita)
We're replaced a 1" pico high reflector and a black glass behind with non-pico version in OMCR path. PSL beam was not available so no alignment.
We removed the following components from HAM6 (refer to D1000342):
- M9. This is aforementioned 1" high reflector on left handed Siskiyou and pico with black glass behind. Pole and base plate were reused. (Non-pico Siskiyou that was used as a replacement is right-handed, not left.)
- 90:10 splitter on a Siskiyou lens mount.
- Black glass dump to receive the reflection of 90:10 splitter.
- M10, this is a 2" high reflector with picos and black glass behind.
- M11, this is a 2" 50:50 splitter without picos.
- The entire OMCR QPD sled including QPDs/cable assy (D1101654, S1108061).
- In-chamber DB25-four mighty mouse cable for pico (D1000238, S1105053).
We found that the black glass dump had some fogging on one of the two panels. Photos to follow.
Yesterday Terry, Nutsinee and I also prepared for tomorow's in chamber work by settings the apertures in their original places on the squeezer path, and aligning the beam produced by scanning the OPO through the apertures. We then moved the apertures out of the way.
1st attachment shows before the change. Green is uninstalled, red is replaced.
2nd is after.
3rd, 4th. Fogging apparent for left panel of the black glass V dump. The difference between these two is that I'm illuminating different part of the panel using a green flashlight.
5th. Right panel under the similar lighting. The fogging is much less severe.
6th, 7th. Outer side of the left panel also has fogging.
Note that I was able to wipe this off easily using a dry Vectra Alpha wipe, it didn't need any force, just wipe and it's off. I only wiped off the left 1/4 of the inside of the left panel that looks foggy in picture 4.
The dump is on the flow bench in the cleaning area next to optics lab in OSB, if somebody wants to inspect.