Danny, Georgia

Summary: We have fixed the ETMY HWS alignment and are ready for an overnight ring heater test.

Somehow after last week's Tuesday maintenance, the ETMY Hartmann wavefront sensor SLED beam became misaligned on the table before injection into the chamber. Today Danny and I went down and fixed the alignment. We checked that all the optics on the SLED path were appropriately bolted to the table and replaced the clamp on the lens/iris directly after the SLED as it was not fully on the translation stage. We co-aligned the SLED beam to the ALS reflected beam, and aligned both onto the camera. Screenshots of the streamed HWS camera image of the Hartmann beam, and the ALS beams attached. The ALS beam is ugly as it consists of the junk light rejected by the polarising beamsplitter.

We closed the SLED iris so that (by eye) the cladding modes were mostly blocked. This reduced the beam size on the HWS camera.

We forgot to play around the the mode matching today, and the beam still looks like it converges too early on the path on the table. Next time we get the chance we need to look at waist position as a function of iris aperture.