cheryl.vorvick@LIGO.ORG - posted 23:21, Friday 26 April 2019 (48801)
the benefits of aligning the IO FI to center on Calcite Wedge 1 (CW1)
- Simple put, one beam in, two beams out, or at least as close as possible to this ideal.
- Images 1 and 2.
- The baffles were carefully placed to pick off unwanted beams.
- Images 3 and 4.
- I observe a number of beams, in HAM2, and a couple that are controlled by PRM, which may be low power, but do appear to be hitting optics and a couple of shinny baffles.
- Images 5 and 6, IMC only locked, Images 6 and 7, full IFO locked at 35W.
- There is no way for a beam to travel through the FI and escape CW1 or CW2, based on the calcite wedge baffle geometry.
- Image 8.
- Which means we have 2 beams escaping the IO FI baffles on the way toward REFL, and moving as PRM moves.
- Two final images, of a beam, located just today, clipping on the CW1 SiC baffle, the baffle aperture is yellow, and the beam is circled in red, and may be somewhat in the location of REFL.
- Images 9 and 10.
- With the CW1 centered, the beams recorded here are more likely to be dumped in the IO FI, or guided to locations that are known to be of no consequence, or at least as close as possible to this ideal.
Images attached to this report
