Minutes of the Tracker Meeting

June 24, 2004

 

Action Items:

1.    Sandro: check on the Aeroglace and Nusil shipments

2.    Nanda: check on and report status of the sidewall spec

3.    Martin: review tungsten surface preparation

4.    INFN: send photos of the 55C T/V test

5.    Nanda: check on and report status of the top/bottom tray assembly procedure

6.    Martin (and others): review the PS-01801 G&A procedure document

 

      - EM Vibe Test update: the x-axis vibration finished, and all test goals were completed a day early!

      - Shipments:

            * Aeroglaze primer and paint (2 shipments): have they arrived?  Nobody in the meeting could confirm.

            * Nusil CV-2502: has it arrived?  Sandro said it probably is in the Malpensa customs office

      - Status of T/V test preparations: we did not have time to cover this subject

            * TEM/PS for thermal-vacuum operation

            * Cables for the TEM/PS

            * Thermal stabilization for the TEM/PS

      - Status of tower functional test preparations: we did not have time to cover this subject

            * Support needed from SLAC (Hiro Tajima and I&T experts)

      - Sidewall fabrication

            * Titanium washers: inspection results from Italy on the countersink angle

Andrea reported that the M4 washers and M2.5 washers have 100 degree countersink angles and so are okay.

Sandro requested that we make the M2.5 screws such that they are easily distinguishable between the 100 degree and 120 degree countersinks.  Martin said that they are easily distinguished by the head size.

Robert asked about the plan to order Tower-A fasteners.  Martin et al are currently reviewing all the fasteners.  Jeff thinks he can get screws in 2 weeks.

            * Completion/release of the spec document

                  Nanda will check with Riccardo. 

            * Schedule for Tower-A sidewalls

                  No schedule was presented.

            * Prepreg amounts needed per tower: there was not time to discuss this.

      - Mid-tray production

            * Status and status reporting (not just Tower A, but also B, 1, 2, etc): status report was not discussed

            * Update on 3M-2216 NCR.  Sandro sent the following report:

4 trays (MID type with 3%Xo converters) have been tested under vacuum for more than 16hours at 50micro-bar at RT without any kapton delamination.  After 16 hours at 50micro-bars at 55 Celsius degrees we found:

a) mid tray SR10 was perfect

b) mid tray SR17 tray had a very little kapton ripple, <<0.1mm, possibly not due to the thermo vacuum test, and a bubble 1cm dia.

c) mid tray SR 07  had 2 1cm diam bubbles

d) mid tray SR 11 had 2 serious delamination of the kapton over 2 tungsen plates.

3 trays (07,10,17) can be used because the bubbles and the delaminations are small in dimension and height (<<0.1mm); the bubbles have to be etched (this needs review by MRB---RJ)

1 tray cannot be used

The delamination is clearly due to a poor adhesion of the 3m 2216 to the tungsten plates.  The Tungsten plates have been slightly sanded so as not to lose planarity and material.  New surface preparation of the W plates is under investigation.

To understand if the situation is stable, we are performing a new thermal-vacuum cycle on the 4 trays

 

Jim asked about experience with previous tests.  Sandro said that there were tests to 60C at the very beginning of development work without silicon but with a different shield plane on the bias circuit and at atm pressure.  EM trays went to 52C in T/V testing and were inspected afterwards, but they did have silicon ladders on already.  2 of those trays had the latest Kapton foil.  The other trays had the ½-oz foil with hatched shield plane.

 

Martin will look into Tungsten surface preparation.  He would like to know the exact procedure used by Plyform for the trays in question.

Nanda said that 20 trays have been bonded with Kapton so far.  INFN will try to remove Kapton from trays with problems.

Ben is sending info on recommended surface prep.

INFN will send photos from today's test, and we will hold a follow-up meeting at 7:30 Friday.

 

Bias circuit issue: there is very good evidence that the circuits are all good.  They were inspected 100% at SLAC, and Parlex has excellent traceability showing that the plating was done and vias were tested.  Nevertheless, they screwed up the coupons on many panels by masking over them during the gold plating procedure.  There will be an MRB Friday morning.  SLAC will make a case to use the circuits with bad coupons, but from each lot do DPA on one circuit.  INFN will wait for the outcome of the MRB before bringing up the issue with Plyform.

      - Bottom/top tray fabrication

            * Completion/release of the assembly procedure document

Nanda will find out the status.

            * Static test plate shipping schedule: not discussed

            * Bottom/top tray schedule: Assembly will start mid next week

      - Tray assembly at G&A

            * Schedule for tests with non-flight trays: assembly should start early next week.

Sandro reported that G&A is doing tests on mockups.  In wire bonding tests, all wires have >5 g strength, which is acceptable (but G&A was not too happy with uniformity).  G&A is now working on doing the encapsulation without bubbles.  They have finalized the process for gluing MCMs.

            * Completion/release of the assembly drawings

Martin expects these to go out tomorrow for release.

            * Completion/release of the assembly procedure document

                  Martin will review the document.  Sandro will send the drawing references to Robert.

            * Schedule for start of tray assembly and completion of tower A trays: start hopefully next week

      - Tower A schedule: Sandro said that after some experience next week at G&A he will be able to define a precise schedule.

      - Travel plans: not discussed

      - A.O.B.