Jenne, Thomas, Sheila

The message is that we don't think that we need to move the OMC to have OK clearances in HAM6. 

• This morning Jenne and Thomas used a card to find positions of SR3 and SR2 which were roughly centered in the Faraday apperature (by moving both optics until they could not find a beam).
• Cheryl and Jeff measured 5.34 W of power going into the IMC from inside the PSL, while the IMC_PWR_IN diode was reporting 6W.  Thomas is updating the calibration. 
• We measured 11.4 mW in HAM6, so with 5.34W of input power, 80% IO throughput, 0.03% PRM transmission, 0.25 from the beam splitter in single bounce, and SRM transmission of 0.32, we expect 10.3 mW in HAM6.  If all these numbers are correct, it could be a problem with our power meter calibration.  We can try to repeat this measurement in HAM6 with the same power meter as was used in the PSL.
• We roughly aligned the path onto AS_C by steering all three of the steering optics, and translating the lens closer to OM1. 
• Once AS_C was aligned we closed the SRC2 loop from AS_C to SR2, and steered SR3 to find the edges of the aperture by watching AS_C_SUM.  We centered ourselves in this aperture with the alignment sliders as shown in the screenshot.
• We then returned to HAM6 and measured clearances and beam centering on the OMs. 
  • The beam from HAM5 is ~27mm from the edge of the OM2 cage, and centered on OM1 within a mm.
  • The lens in the AS_C path has plenty of clearance, maybe about an inch.
  • The spot on OM2 was 9 mm from center in the +X direction.  We rotated OM1 to center this better.
• • Before the OM1 rotation we had 8-9mm of clearance from the HAM5 beam to the fast shutter structure, but after rotating OM1 we estimate that we should now have 12-13 mm of clearance.  We have left the fast shutter out of the path for now since we do not have high voltage in HAM6 to open it.
  • The OM1-OM2 beam was 25mm from the OM3 cage when we started, and should now be larger.
  • We rotated OM2 to roughly center the beam on OM3's aperture, and saw that the beam is entering the hole in the OMC shroud.
• Still to do on HAM6 (not in order):
  • Reposition beam dump after OM2.
  • Put fast shutter back in path.
  • Dress fast shutter wires (llo log 37301)
  • Align onto OMC QPDs (might require removing shroud).
  • Double check AS_C beam path is centered on optics.
  • Use viewport simulator to check AS air beam position.