Georgia, Danny
With different ITM spot positions we have changed how the point absorbers contribute to the overall optical path distortion. This makes the first CO2Y mask design (Mask 1) less helpful, Aidan designed a second iteration of the CO2Y mask (Mask 2) in order to better accommodate for the new optical path distortion. We installed this new mask today into the annular mask beam flipper.
We believe the mask should be installed in the flipper as indicated in the first figure.
Some notes on the installation of Mask 2:
- Based on the installation orientation, we think the major axis of the elliptical aperture may be along the wrong axis.
- Installation with inital flipper position
- Attached FLIR images show some centering differences between Mask 1 and Mask 2 after initial installation.
- Measured optical path distortion after turning the CO2Y on with Mask 2. (.9 W of CO2 above nominal)
- Translated the mask to acquire better overlap of the aperture positions between Mask 2 and Mask 1
- Some FLIR images showing the new centering differences after translating
- Measured optical path distortion after translating Mask 2 (2W of CO2 above nominal)
- It looks like we translated the flipper to far in the vertical direction (Horizontal on the HWS).
- We still need to adjust position and mask rotation before testing.
Made some fine adjustments to the installed mask (Mask 2). A FLIR image is attached. Also attached are Hartmann images comparing the centering of the optical path distortion from the point absorbers (left) and the optical path distortion of CO2Y with the mask in its current alignment. It is important to note that the optical path distortion shown in the HWS image to the right is caused by a short duration 2.4W CO2 step up and not fully representative of the distortion you expect to see at thermal equilibrium.
