J. Oberling, B. Weaver

Yesterday I completed the install and alignment of the AWC mirrors and beam dump on HAM5.  Betsy and I placed the mirrors on the table on 11/30/2017 and intially aligned them (as described below); I then installed and aligned the black glass beam dump yesterday.  The install went smoothly, the only slight hitch being an interfering OFI dog clamp forcing me to slightly move the beam dump from the position called out in the H1 AWC drawing (D1700468); it is ~3/4" closer to the OFI than called out for in the drawing.  The first picture shows the completed install, and the second shows a close up of the AWC beam dump with its slightly changed position.

The optics were aligned using the same laser setup used for the temporary oplev from the SRM swap from earlier in the vent (3rd picture), in which a spare optical lever laser was used in conjunction with a fiber collimator and one of the Brunson tripods from IAS; the viewport emulator (4th picture.  Hi Betsy!) was attached to the HAM chamber to simulate the viewport locations.  The alignment itself was very straigtforward and proceeded with the following steps:

• The beam was centered on the center viewport emulator and the 1st AWC mirror.
• The 1st AWC mirror was then adjusted until the beam was centered on the 2nd AWC mirror.
• The 2nd AWC mirror was adjusted until the beam entered and exited the apertures on the rear SRM baffle.
• Using both AWC mirrors, the beam was walked until it was centered on the entrance and exit holes in the rear SRM baffle.
• The beam dump was installed such that the beam was contained.

After I installed the beam dump, I double checked the alignment and all was still good.  This completes the HAM AWC in-vacuum installation.