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Reports until 12:29, Wednesday 13 November 2013
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betsy.weaver@LIGO.ORG - posted 12:29, Wednesday 13 November 2013 - last comment - 13:33, Friday 15 November 2013(8503)
ETMx pitch final alignment - and FC issue

This morning Travis, Jason and I made the ~last pitch alignment of the ETMx.  We also pulled the FC from the inside of the 2 East viewports and the ETMx CP-AR.  However, when we pulled the FC off of the CP-AR, the thin central portion of the sheet left segments of a ring around the center of the optic.  Par for the course.  And, of course, I could not get any good pictures of the feature so I'll attach a sketch shortly.  I'll get with COC to see what I should do - note, I cannot get the spray cone on to resheet the First COntact and start over, so either we'll need to live with these remnants, or I'll have to get crafty with a smaller cone.

 

But, back to the alignment - we aligned the ETMx to an offset pitch pointing such that when we pull the First Contact sheet from the HR surface, the optic bounces up to point the nominal pitch.  However, this does not help TMS with their alignment now.  After consult with IAS/TMS we decided to put the offset pitch onto the bias slider of the ETMx.  We have the range according to the uRad-calibrated bias slider, however Jason is going to go map it out and confirm the calibration of the slider with his optical equipment (still set up).  This should not take long, and he will leave the offset bias enabled for TMS to start their alignment asap.

Comments related to this report
betsy.weaver@LIGO.ORG - 13:46, Wednesday 13 November 2013 (8505)

Attached is my sketch of the CP-AR FC remnants/wisps left after I pulled the full sheet today.

Images attached to this comment
betsy.weaver@LIGO.ORG - 13:51, Wednesday 13 November 2013 (8506)

Note, these features are very small and kinda difficult to see, so they might be survivable...

jason.oberling@LIGO.ORG - 13:58, Wednesday 13 November 2013 (8507)AOS

ETMx pitch after this morning's adjustments:

  • Pitch: 383 µrad down
    • Target Pitch: 360 µrad down (8 µrad optic pitch + 352 µrad FC correction)
    • Error: 23 µrad
    • Tolerance: ±50 µrad
calum.torrie@LIGO.ORG - 08:41, Thursday 14 November 2013 (8529)
With reference to this alog 8503

We first note it is not a CP but an ERM AR side (TMS side).

As a result of it being a ERM AR side (and location) the small amount of first contact should either be left or removed with acetone if you really want too.

Cheers, Calum (with input from GariLynn)
betsy.weaver@LIGO.ORG - 08:56, Thursday 14 November 2013 (8530)

Great!  Sorry about the error in the reference to a CP - indeed, it is of course an ERM!  Thanks!

betsy.weaver@LIGO.ORG - 13:33, Friday 15 November 2013 (8581)

Also to note - at the time of this alignment, I closed the Ring Heater around the ETMx.

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