[Aidan, Camilla, TJ]

We returned to the ETMX to work on the HWS this afternoon. We adjusted the positions of lenses 2 and 3 and the HWS itself to better match the nominal/design layout. 

• L1 to L2 was 533mm. We added 76.6mm to bring that up to 610mm (by moving L2 closer to the HWS source and L3)
• L2 to L3 was 1041mm. In addition to the move above, we moved L3 closer to L2 by 36mm to bring the distance between L2 and L3 to 929mm.
• We moved the two mirrors in front of the HWS closer to it by 3" each. This brought the L3 to HWS distance down to approximateoy 1350mm from 1500mm. This needs to come down another 50mm to 1300mm but we don't have space right now

Aside from this, it is obvious from an inspection of mirrors and the HWS return beam that there is a LOT OF DUST on all the optics. Also, the HWS beam wanders on the camera by small amounts - I can put my finger on the picomotor mount and see signifcant movement of the beam. The high spatial frequencoes in the return beam (from diffraction from dust) coupled with the beam motion will create significant noise. 

We need to clean the optics.

TJ and Camilla did clean the bottom periscope mirror (pictures to follow) but there are still more optics to clean.