We identified the return beam from the ITMY HR surface. The HWY periscope is aligned such that this is now returned to the HWS CCD. We confirmed that this is the ITMY HR reflection by running the ring heater for several hours and measuring a negative thermal lens virtually identical to the one predicted by the online simulation.

The size and shape of the reflection is consistent with what we expect and what we see at LLO. We see features such as the shadow of the earthquake stops. The beam shows evidence of a considerable amount of dust on one or more of the HWS optics which we will need to clean. Also - we've not yet placed the HWS CCD at the conjugate plane of the ITM HR surface. We will also want to look at shrinking the beam envelope size by 30% or so (by adjusting the SLED fiber launcher) to make the beam more consistent with LLO and reduce diffraction from the edges.

More detailed report to follow.

H1 - HWSY return beam

L1-HWSY return beam