Betsy, Travis, Rick

How today went:

We spent a few hours this morning working on the in-vac side of the new ESD connector termination checkouts. 

At ~2pm we pulled the FC sheet off of the ETMy-HR (painted on last night).  We immediately saw that the 3 larger FC remnants that were causing all of the glint in the cavity arm were removed.  Yay!  However, it was also immediately clear (with the green flashlight) that the 3" ring feature and mottled haze were still there. 

We took a break at 3pm and spoke to a wider SYS+ audience where it was determined we would attempt to do a test drag wipe on the mottling nearer the edge of the optic.  We worked on getting pictures of numerous mottled areas in the haze of the donut shape on the ETMy-HR before doing some test drag wipes.  Then we chose an area toward the top of the optic where there was another relic IAS window circle print near the 12 o'clock position to test drag wiping.  After numerous failed attempts at performing the light-duty friction-only drag wiping technique on this area I resorted to folding the lens wipe a few times and applying pressure during the drag wipe.  This made a smudge where I wiped which I then had to spend another ~5 wipes removing.  We then reevaluated the mottling and found that we might have improved it in one small place, but not the entire area I had been working on.  We then redirected a streaky area at the bottom of the optic to see if I could get a better technique down.  No such luck and I again had to resort to applying pressure numerous times in order to see an improvement.  Since we had better pictures of the 12 o'clock position mottling area that I had been working on earlier, we decided to revisit that area.  I again made an attempt at friction-only drag wiping of this top area.  In the process I must have lightly swiped the optic with my glove because when inspecting the optic after the drag wipe, we found a ~2mmx2mm patch of particulate just outside of the 3" ring near the center of the optic.  Brilliant.  We also found more particulate on the optic from the waving lens tissues.  We tried to blow them off with a few minutes of N2.  This did not seem to work.  One of the particles was quite large and even a light dab with an swab did not move it (in fact, ~5 attempts to snatch it off via dabbing failed).  Rick captured a few pictures of the "new" features.

At this point we aborted the drag wipe testing and carefully repainted FC back on.  I was very careful to not brush across the large particle nor the "patch" area very much.  I applied very thick ~1 inch long strokes which at first were more like dabs near these areas.  (All other saturated sloppy strokes were ~1-2" in length, repeated.)

I do not think we can drag wipe the full surface (or even the central ~8") of the ETMy-HR.  We were not sucessful in ~25 attempts to get a good pull on the optic except for in the localized areas I mentioned above when I used finger pressue.  And after these attempts we added contaminant to the surface by accident.

The optic size obviously makes it hard to work with.  The working area is too small for 2 hands, elbows, flashlights, your head, etc.  Then, the task is too hampered by suspension brackets and braces to get good surface tension with the flat lens tissue.  The wipe wants to continue to pull off the surface and ripples easily.  As well (or worse), we had a hard time getting the wetted wipe to the surface before the acetone dried.

Rick plans to attach some pictures to this alog so check back later or tommorrow.