Georgia, TVo

We walked the picomotors on the periscope for ITMX HWS in order to get rid of the prompt reflection and reduce the clipping on the baffles.  Attached are the before and after photos.  

During about 30 minutes of DC Readout when no transient heating is being applied so we expect very small changes in spherical power as a function of time, the ITMX HWS is still noisier than ITMY HWS by about a factor of 3 just looking at the time series.  This is better than before when we had a prompt reflection that was screwing up the fitting for the spherical power, maybe we can go back to the same alignment but digitally subtract the beam and keep the useful HWS beam, this is in progress.

After this alignment adjustment the noise got better but attached are the gradient plots for about 5 minutes for both HWS, it show that ITMY sees much less optical path distortion than ITMX and there seems to be a very large gradient vector for ITMX around coordinates=[+0.01, +0.05].  At first glance, this may be dust somewhere in the optical path so we'll investigate the optical table with an ion gun.  This "dot" remains persistent for multiple time frames and was present both before and after the pico-ing

There is also a large amount of contours in the upper left hand section, which looks like it's due to the single gradient arrow at coordinates=[-0.1,+0.75]. It is not obvious the root cause since it doesn't look like a normal fringe pattern and we only have one real data point there but we can try to pico away from the left hand side of the baffle and see if this improves the contour plots.