J. Kissel
IIET Ticket 24286

I've been working on an idea with Jason Oberling and Richard McCarthy to get Michael Ross and the UWash team an optical lever (or at least most of the components thereof) for study at UWash, with the eventual goal to improve the system for better performance and stationarity. That idea includes them borrowing one of the now defunct / decommissioned HAM table optical levers (see ECR E1700123).

There was some confusion about which whitening chassis are still in use after the prior-to-O3 rearrangement of chassis usage (see E1800038), so I went out and took inventory of the status. I'll attach a bunch of pictures to this aLOG that support the inventory and/or prove its validity.


                               HAM2     HAM3     HAM4      HAM5
Connected to Viewport?          Y        Y        Y         N
Yellow viewport protector?     n/a      n/a      n/a        Y
Still has fiber?                Y        Y        Y         Y
Still has laser?                N        N        N         N
Still has cooler?               Y        N        N         N
QPD connected to whitening?     Y        Y        Y         Y
    Where?                    SUS-R1    SUS-R1   SUS-R4   SUS-R3
                              Board 1   Board 2  Board 1  Board 1
    What's in the other
    board?                    HAM3     HAM2      Nothing   SR3

    BIO Daughter Board?         Y        Y        Y         N


With this inventory, I think it makes the most sense to extract 
    - the HAM5 Table Oplev's transceiver module, and associated fiber bundle since it's already disconnected from the vacuum system, and 
    - the HAM4 Table Oplev's whitening chassis, and associated daughter board since it's alone in its whitening chassis with nothing else connected.
    - the HAM2 Table Oplev's old-style cooler

This still leaves HAM2/HAM3 table oplev's use of the whitening chassis and daughter boards in SUS-R1 as spare here on site (Richard's worry was that after ECR E1800038 there weren't *two* whitening chassis left, but only one. Now that we know there's two, we're more willing to part with one). 
The PR3 / SR3 / BS / ITM coolers used to stabilize the oplev laser's temperature are quite different now, but I'll check with Jason if he still uses this empty HAM2 cooler as his temperature tuning cooler for spares.

Also, I know even saying this out loud means work for an over-taxed vacuum team, and it probably won't be deemed a priority, but I can't help but say that it seems like we should *truly* decommission the HAM2, HAM3, and HAM4 table optical levers in the fullness of time: disconnect their bellows from the vacuum system and cover the viewport with a yellow steel cover, assuming we put at some sort of black glass / anti-reflective / absorptive substance on the inside to morb, if not at least mitigate, stray / scattered light.