[Deepak N., Rodica M., Chris M.]

Tonights Work:
It turns out that the MC Refl beam is elliptically polarized (we may want to add a polarizer on IOT2L to correct this).  To fix this we used a TFP after the MC Refl periscope.  We then returned to the activity of the prior night which was to use the Faraday as a reference to set the polarization for IM1 so that we could measure the transmissivity.   These values are below.  Note that the values measured for IM4 may change slightly with the final alignment, but IM1 is in the final state.  





Optic
Incident
Transmitted
Trasnmissivity


IM1
151 +- 2 mW
78.5 +- 0.5 uW
520 +- 10 ppm


IM4
165.4 +- 1 mW
389 +- 5 uW
2350 +- 50 ppm


ROM LH1 (BS behind IM4)
389 +- 5 uW
29.4 +- 0.2 uW
7.56 +- 0.15 %



Alignment offsets on the IOO suspensions as of today:


Suspension
Pitch (MC in urad/ IM in cnts)
Yaw (MC in urad/ IM in cnts)


MC1
-46
-3750


MC2
65
137


MC3
320
-4300


IM1
1030
-900


IM2
-700
-520


IM3
3250
-500


IM4
-3250
4250



What is left to do next week:
* Align IM3 and IM4 to PRM/PR2 (this requires IAS to be finished/have irises placed)
* Use a HWP in the Faraday to screw up the polarization and check that PRM retro-reflects.  
* Align the forward rejection beam from the Faraday. 
* Check the placement of the ellipse shaped baffle between the Faraday and IM4 (this also needs to pass the parking beam).
* Check the placement of the MC3 AR baffle.
* Align the IFO Refl beam into HAM 1.
* Align auxiliary beams behind IM4 using the viewport replicator.
* Measure transmissivity of IM4 and the beamsplitters in the paths behind it.
* Check the alignment of MC2 Trans with a red beam.
* Check that MC Refl and IM1 Trans makes it through the viewports using the viewport replicator.
* Assist with aligning the optics behind PR2 using Keita's documented procedure (if time permits).  
* Replace/ remove all temporary things noted in list below.
* Drink beer.

Temporary things:
* Irises near MC1, MC2, and MC3.
* Irises near IM1 and IM2.
* Replace HWP and set the polarization.
* MC3 AR baffle.
* Two mirrors for MC Refl reclamation.
* IAS irises.
* Beamblocks.
* Baffles moved for IAS alignment.
* Tools.
* Replace hard aperture clamps.