Notes on TART status call at
Tom Venator
1) Next
call tomorrow at
2) We need to get Henning on the phone with us to discuss his ideas and concerns with the rest of the team.
3) We did not discuss the cables. This discussion has been put off until tomorrow’s call at 12:00 EST. This is because none of the SLAC folks working the cable issues were available. Parlex trip is on for Friday this week.
4) Robert Johnson gave a positive summary of last Friday’s MRB+ meeting on the earlier tracker call.
a. Teledyne is planning to clean the fixturing. The exact procedure is TBD but Fred sent an email to Dave Rich suggesting scotchbrite and acetone followed by an IPA wipe. Dave was not on the call so perhaps he can clarify this tomorrow.
b. Teledyne tape samples were in Jim Lohr’s hands just after the call. Tavi is looking for some tape here. Should have a report tomorrow.
5) The idea of augmenting the electrical screening with a SAM scan is still awaiting the test of an MCM with a channel map.
a. Robert sent one last week but it has not been found. He was going to ask Jeff Tice to check for shipping information.
b. We are going to send Jim Lohr’s MCM, dated 5/18, back to Robert for electrical screening.
6) Diane Kolos has MCM SN775. This is the unit she pulled the epoxy off as a lump. She is now looking for contaminates on the surfaces.
a. Today she should have FTIR results. We are not optimistic that this will sow much.
b. The next step is to use an SEM.
c. If the SEM doesn’t work, then an ESKA (sp?).
d. If the ESKA doesn’t work we plan to send it out for an AUGER test.
7) John Ku discussed his analysis to date.
a. He is going to abandon the 3d model idea. It is not necessary for what we want. We are assuming that a failure of the encapsulant bond takes the wires with it so are not real concerned with wire stresses.
b. He will rerun the plane-strain analysis to see what the failure modes look like under thermal loading with some revision to the material properties. He hopes to have something by tomorrow.
c. He will add a case qualitatively assessing moisture effects to see if this is another important effect on the MCMs. He will report on this tomorrow as well.
8) For tower B and tower 1 trays added visual inspection step to look for debonded areas. (Used microscope at around 10x to 20x). None seen so far.
9) Current set of tower 1 MCMs are largely post 7/1 parts. They were selected on the basis of the visual and electrical inspections, not date.
10) While the preference is too stick with the existing design for future units Brian is making the first try at a cover by a 4 segment set of fiberglass pieces on the existing dams. This is being done at Teledyne today.